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Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
 Andrii Nakryiko
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1a8df7fa00 |
libbpf: add BPF token support to bpf_btf_load() API
Allow user to specify token_fd for bpf_btf_load() API that wraps kernel's BPF_BTF_LOAD command. This allows loading BTF from unprivileged process as long as it has BPF token allowing BPF_BTF_LOAD command, which can be created and delegated by privileged process. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231130185229.2688956-15-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Andrii Nakryiko
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37891cea66 |
libbpf: add BPF token support to bpf_map_create() API
Add ability to provide token_fd for BPF_MAP_CREATE command through bpf_map_create() API. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231130185229.2688956-14-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Andrii Nakryiko
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ecd435143e |
libbpf: add bpf_token_create() API
Add low-level wrapper API for BPF_TOKEN_CREATE command in bpf() syscall. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231130185229.2688956-13-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Andrii Nakryiko
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d734ca7b33 |
bpf,lsm: add BPF token LSM hooks
Wire up bpf_token_create and bpf_token_free LSM hooks, which allow to allocate LSM security blob (we add `void *security` field to struct bpf_token for that), but also control who can instantiate BPF token. This follows existing pattern for BPF map and BPF prog. Also add security_bpf_token_allow_cmd() and security_bpf_token_capable() LSM hooks that allow LSM implementation to control and negate (if necessary) BPF token's delegation of a specific bpf_cmd and capability, respectively. Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231130185229.2688956-12-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Andrii Nakryiko
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66d636d70a |
bpf,lsm: refactor bpf_map_alloc/bpf_map_free LSM hooks
Similarly to bpf_prog_alloc LSM hook, rename and extend bpf_map_alloc hook into bpf_map_create, taking not just struct bpf_map, but also bpf_attr and bpf_token, to give a fuller context to LSMs. Unlike bpf_prog_alloc, there is no need to move the hook around, as it currently is firing right before allocating BPF map ID and FD, which seems to be a sweet spot. But like bpf_prog_alloc/bpf_prog_free combo, make sure that bpf_map_free LSM hook is called even if bpf_map_create hook returned error, as if few LSMs are combined together it could be that one LSM successfully allocated security blob for its needs, while subsequent LSM rejected BPF map creation. The former LSM would still need to free up LSM blob, so we need to ensure security_bpf_map_free() is called regardless of the outcome. Acked-by: Paul Moore <paul@paul-moore.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231130185229.2688956-11-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Andrii Nakryiko
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c3dd6e94df |
bpf,lsm: refactor bpf_prog_alloc/bpf_prog_free LSM hooks
Based on upstream discussion ([0]), rework existing
bpf_prog_alloc_security LSM hook. Rename it to bpf_prog_load and instead
of passing bpf_prog_aux, pass proper bpf_prog pointer for a full BPF
program struct. Also, we pass bpf_attr union with all the user-provided
arguments for BPF_PROG_LOAD command. This will give LSMs as much
information as we can basically provide.
The hook is also BPF token-aware now, and optional bpf_token struct is
passed as a third argument. bpf_prog_load LSM hook is called after
a bunch of sanity checks were performed, bpf_prog and bpf_prog_aux were
allocated and filled out, but right before performing full-fledged BPF
verification step.
bpf_prog_free LSM hook is now accepting struct bpf_prog argument, for
consistency. SELinux code is adjusted to all new names, types, and
signatures.
Note, given that bpf_prog_load (previously bpf_prog_alloc) hook can be
used by some LSMs to allocate extra security blob, but also by other
LSMs to reject BPF program loading, we need to make sure that
bpf_prog_free LSM hook is called after bpf_prog_load/bpf_prog_alloc one
*even* if the hook itself returned error. If we don't do that, we run
the risk of leaking memory. This seems to be possible today when
combining SELinux and BPF LSM, as one example, depending on their
relative ordering.
Also, for BPF LSM setup, add bpf_prog_load and bpf_prog_free to
sleepable LSM hooks list, as they are both executed in sleepable
context. Also drop bpf_prog_load hook from untrusted, as there is no
issue with refcount or anything else anymore, that originally forced us
to add it to untrusted list in
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Andrii Nakryiko
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8062fb12de |
bpf: consistently use BPF token throughout BPF verifier logic
Remove remaining direct queries to perfmon_capable() and bpf_capable() in BPF verifier logic and instead use BPF token (if available) to make decisions about privileges. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231130185229.2688956-9-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Andrii Nakryiko
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4cbb270e11 |
bpf: take into account BPF token when fetching helper protos
Instead of performing unconditional system-wide bpf_capable() and perfmon_capable() calls inside bpf_base_func_proto() function (and other similar ones) to determine eligibility of a given BPF helper for a given program, use previously recorded BPF token during BPF_PROG_LOAD command handling to inform the decision. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231130185229.2688956-8-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Andrii Nakryiko
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e1cef620f5 |
bpf: add BPF token support to BPF_PROG_LOAD command
Add basic support of BPF token to BPF_PROG_LOAD. Wire through a set of allowed BPF program types and attach types, derived from BPF FS at BPF token creation time. Then make sure we perform bpf_token_capable() checks everywhere where it's relevant. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231130185229.2688956-7-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Andrii Nakryiko
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ee54b1a910 |
bpf: add BPF token support to BPF_BTF_LOAD command
Accept BPF token FD in BPF_BTF_LOAD command to allow BTF data loading through delegated BPF token. BTF loading is a pretty straightforward operation, so as long as BPF token is created with allow_cmds granting BPF_BTF_LOAD command, kernel proceeds to parsing BTF data and creating BTF object. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231130185229.2688956-6-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Andrii Nakryiko
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688b7270b3 |
bpf: add BPF token support to BPF_MAP_CREATE command
Allow providing token_fd for BPF_MAP_CREATE command to allow controlled BPF map creation from unprivileged process through delegated BPF token. Wire through a set of allowed BPF map types to BPF token, derived from BPF FS at BPF token creation time. This, in combination with allowed_cmds allows to create a narrowly-focused BPF token (controlled by privileged agent) with a restrictive set of BPF maps that application can attempt to create. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231130185229.2688956-5-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Andrii Nakryiko
|
4527358b76 |
bpf: introduce BPF token object
Add new kind of BPF kernel object, BPF token. BPF token is meant to
allow delegating privileged BPF functionality, like loading a BPF
program or creating a BPF map, from privileged process to a *trusted*
unprivileged process, all while having a good amount of control over which
privileged operations could be performed using provided BPF token.
This is achieved through mounting BPF FS instance with extra delegation
mount options, which determine what operations are delegatable, and also
constraining it to the owning user namespace (as mentioned in the
previous patch).
BPF token itself is just a derivative from BPF FS and can be created
through a new bpf() syscall command, BPF_TOKEN_CREATE, which accepts BPF
FS FD, which can be attained through open() API by opening BPF FS mount
point. Currently, BPF token "inherits" delegated command, map types,
prog type, and attach type bit sets from BPF FS as is. In the future,
having an BPF token as a separate object with its own FD, we can allow
to further restrict BPF token's allowable set of things either at the
creation time or after the fact, allowing the process to guard itself
further from unintentionally trying to load undesired kind of BPF
programs. But for now we keep things simple and just copy bit sets as is.
When BPF token is created from BPF FS mount, we take reference to the
BPF super block's owning user namespace, and then use that namespace for
checking all the {CAP_BPF, CAP_PERFMON, CAP_NET_ADMIN, CAP_SYS_ADMIN}
capabilities that are normally only checked against init userns (using
capable()), but now we check them using ns_capable() instead (if BPF
token is provided). See bpf_token_capable() for details.
Such setup means that BPF token in itself is not sufficient to grant BPF
functionality. User namespaced process has to *also* have necessary
combination of capabilities inside that user namespace. So while
previously CAP_BPF was useless when granted within user namespace, now
it gains a meaning and allows container managers and sys admins to have
a flexible control over which processes can and need to use BPF
functionality within the user namespace (i.e., container in practice).
And BPF FS delegation mount options and derived BPF tokens serve as
a per-container "flag" to grant overall ability to use bpf() (plus further
restrict on which parts of bpf() syscalls are treated as namespaced).
Note also, BPF_TOKEN_CREATE command itself requires ns_capable(CAP_BPF)
within the BPF FS owning user namespace, rounding up the ns_capable()
story of BPF token.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231130185229.2688956-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Andrii Nakryiko
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40bba140c6 |
bpf: add BPF token delegation mount options to BPF FS
Add few new mount options to BPF FS that allow to specify that a given
BPF FS instance allows creation of BPF token (added in the next patch),
and what sort of operations are allowed under BPF token. As such, we get
4 new mount options, each is a bit mask
- `delegate_cmds` allow to specify which bpf() syscall commands are
allowed with BPF token derived from this BPF FS instance;
- if BPF_MAP_CREATE command is allowed, `delegate_maps` specifies
a set of allowable BPF map types that could be created with BPF token;
- if BPF_PROG_LOAD command is allowed, `delegate_progs` specifies
a set of allowable BPF program types that could be loaded with BPF token;
- if BPF_PROG_LOAD command is allowed, `delegate_attachs` specifies
a set of allowable BPF program attach types that could be loaded with
BPF token; delegate_progs and delegate_attachs are meant to be used
together, as full BPF program type is, in general, determined
through both program type and program attach type.
Currently, these mount options accept the following forms of values:
- a special value "any", that enables all possible values of a given
bit set;
- numeric value (decimal or hexadecimal, determined by kernel
automatically) that specifies a bit mask value directly;
- all the values for a given mount option are combined, if specified
multiple times. E.g., `mount -t bpf nodev /path/to/mount -o
delegate_maps=0x1 -o delegate_maps=0x2` will result in a combined 0x3
mask.
Ideally, more convenient (for humans) symbolic form derived from
corresponding UAPI enums would be accepted (e.g., `-o
delegate_progs=kprobe|tracepoint`) and I intend to implement this, but
it requires a bunch of UAPI header churn, so I postponed it until this
feature lands upstream or at least there is a definite consensus that
this feature is acceptable and is going to make it, just to minimize
amount of wasted effort and not increase amount of non-essential code to
be reviewed.
Attentive reader will notice that BPF FS is now marked as
FS_USERNS_MOUNT, which theoretically makes it mountable inside non-init
user namespace as long as the process has sufficient *namespaced*
capabilities within that user namespace. But in reality we still
restrict BPF FS to be mountable only by processes with CAP_SYS_ADMIN *in
init userns* (extra check in bpf_fill_super()). FS_USERNS_MOUNT is added
to allow creating BPF FS context object (i.e., fsopen("bpf")) from
inside unprivileged process inside non-init userns, to capture that
userns as the owning userns. It will still be required to pass this
context object back to privileged process to instantiate and mount it.
This manipulation is important, because capturing non-init userns as the
owning userns of BPF FS instance (super block) allows to use that userns
to constraint BPF token to that userns later on (see next patch). So
creating BPF FS with delegation inside unprivileged userns will restrict
derived BPF token objects to only "work" inside that intended userns,
making it scoped to a intended "container". Also, setting these
delegation options requires capable(CAP_SYS_ADMIN), so unprivileged
process cannot set this up without involvement of a privileged process.
There is a set of selftests at the end of the patch set that simulates
this sequence of steps and validates that everything works as intended.
But careful review is requested to make sure there are no missed gaps in
the implementation and testing.
This somewhat subtle set of aspects is the result of previous
discussions ([0]) about various user namespace implications and
interactions with BPF token functionality and is necessary to contain
BPF token inside intended user namespace.
[0] https://lore.kernel.org/bpf/20230704-hochverdient-lehne-eeb9eeef785e@brauner/
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231130185229.2688956-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Andrii Nakryiko
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909fa05dd3 |
bpf: align CAP_NET_ADMIN checks with bpf_capable() approach
Within BPF syscall handling code CAP_NET_ADMIN checks stand out a bit compared to CAP_BPF and CAP_PERFMON checks. For the latter, CAP_BPF or CAP_PERFMON are checked first, but if they are not set, CAP_SYS_ADMIN takes over and grants whatever part of BPF syscall is required. Similar kind of checks that involve CAP_NET_ADMIN are not so consistent. One out of four uses does follow CAP_BPF/CAP_PERFMON model: during BPF_PROG_LOAD, if the type of BPF program is "network-related" either CAP_NET_ADMIN or CAP_SYS_ADMIN is required to proceed. But in three other cases CAP_NET_ADMIN is required even if CAP_SYS_ADMIN is set: - when creating DEVMAP/XDKMAP/CPU_MAP maps; - when attaching CGROUP_SKB programs; - when handling BPF_PROG_QUERY command. This patch is changing the latter three cases to follow BPF_PROG_LOAD model, that is allowing to proceed under either CAP_NET_ADMIN or CAP_SYS_ADMIN. This also makes it cleaner in subsequent BPF token patches to switch wholesomely to a generic bpf_token_capable(int cap) check, that always falls back to CAP_SYS_ADMIN if requested capability is missing. Cc: Jakub Kicinski <kuba@kernel.org> Acked-by: Yafang Shao <laoar.shao@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231130185229.2688956-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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 Alexei Starovoitov
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3aee2bf9c4 |
Merge branch 'complete-bpf-verifier-precision-tracking-support-for-register-spills'
Andrii Nakryiko says: ==================== Complete BPF verifier precision tracking support for register spills Add support to BPF verifier to track and support register spill/fill to/from stack regardless if it was done through read-only R10 register (which is the only form supported today), or through a general register after copying R10 into it, while also potentially modifying offset. Once we add register this generic spill/fill support to precision backtracking, we can take advantage of it to stop doing eager STACK_ZERO conversion on register spill. Instead we can rely on (im)precision of spilled const zero register to improve verifier state pruning efficiency. This situation of using const zero register to initialize stack slots is very common with __builtin_memset() usage or just zero-initializing variables on the stack, and it causes unnecessary state duplication, as that STACK_ZERO knowledge is often not necessary for correctness, as those zero values are never used in precise context. Thus, relying on register imprecision helps tremendously, especially in real-world BPF programs. To make spilled const zero register behave completely equivalently to STACK_ZERO, we need to improve few other small pieces, which is done in the second part of the patch set. See individual patches for details. There are also two small bug fixes spotted during STACK_ZERO debugging. The patch set consists of logically three changes: - patch #1 (and corresponding tests in patch #2) is fixing/impoving precision propagation for stack spills/fills. This can be landed as a stand-alone improvement; - patches #3 through #9 is improving verification scalability by utilizing register (im)precision instead of eager STACK_ZERO. These changes depend on patch #1. - patch #10 is a memory efficiency improvement to how instruction/jump history is tracked and maintained. It depends on patch #1, but is not strictly speaking required, even though I believe it's a good long-term solution to have a path-dependent per-instruction information. Kind of like a path-dependent counterpart to path-agnostic insn_aux array. v3->v3: - fixed up Fixes tag (Alexei); - fixed few more selftests to not use BPF_ST instruction in inline asm directly, checked with CI, it was happy (CI); v2->v3: - BPF_ST instruction workaround (Eduard); - force dereference in added tests to catch problems (Eduard); - some commit message massaging (Alexei); v1->v2: - clean ups, WARN_ONCE(), insn_flags helpers added (Eduard); - added more selftests for STACK_ZERO/STACK_MISC cases (Eduard); - a bit more detailed explanation of effect of avoiding STACK_ZERO in favor of register spill in patch #8 commit (Alexei); - global shared instruction history refactoring moved to be the last patch in the series to make it easier to revert it, if applied (Alexei). ==================== Link: https://lore.kernel.org/r/20231205184248.1502704-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Andrii Nakryiko
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064e0bea19 |
selftests/bpf: validate precision logic in partial_stack_load_preserves_zeros
Enhance partial_stack_load_preserves_zeros subtest with detailed precision propagation log checks. We know expect fp-16 to be spilled, initially imprecise, zero const register, which is later marked as precise even when partial stack slot load is performed, even if it's not a register fill (!). Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231205184248.1502704-10-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
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Andrii Nakryiko
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18a433b620 |
bpf: track aligned STACK_ZERO cases as imprecise spilled registers
Now that precision backtracing is supporting register spill/fill to/from
stack, there is another oportunity to be exploited here: minimizing
precise STACK_ZERO cases. With a simple code change we can rely on
initially imprecise register spill tracking for cases when register
spilled to stack was a known zero.
This is a very common case for initializing on the stack variables,
including rather large structures. Often times zero has no special
meaning for the subsequent BPF program logic and is often overwritten
with non-zero values soon afterwards. But due to STACK_ZERO vs
STACK_MISC tracking, such initial zero initialization actually causes
duplication of verifier states as STACK_ZERO is clearly different than
STACK_MISC or spilled SCALAR_VALUE register.
The effect of this (now) trivial change is huge, as can be seen below.
These are differences between BPF selftests, Cilium, and Meta-internal
BPF object files relative to previous patch in this series. You can see
improvements ranging from single-digit percentage improvement for
instructions and states, all the way to 50-60% reduction for some of
Meta-internal host agent programs, and even some Cilium programs.
For Meta-internal ones I left only the differences for largest BPF
object files by states/instructions, as there were too many differences
in the overall output. All the differences were improvements, reducting
number of states and thus instructions validated.
Note, Meta-internal BPF object file names are not printed below.
Many copies of balancer_ingress are actually many different
configurations of Katran, so they are different BPF programs, which
explains state reduction going from -16% all the way to 31%, depending
on BPF program logic complexity.
I also tooked a closer look at a few small-ish BPF programs to validate
the behavior. Let's take bpf_iter_netrlink.bpf.o (first row below).
While it's just 8 vs 5 states, verifier log is still pretty long to
include it here. But the reduction in states is due to the following
piece of C code:
unsigned long ino;
...
sk = s->sk_socket;
if (!sk) {
ino = 0;
} else {
inode = SOCK_INODE(sk);
bpf_probe_read_kernel(&ino, sizeof(ino), &inode->i_ino);
}
BPF_SEQ_PRINTF(seq, "%-8u %-8lu\n", s->sk_drops.counter, ino);
return 0;
You can see that in some situations `ino` is zero-initialized, while in
others it's unknown value filled out by bpf_probe_read_kernel(). Before
this change code after if/else branches have to be validated twice. Once
with (precise) ino == 0, due to eager STACK_ZERO logic, and then again
for when ino is just STACK_MISC. But BPF_SEQ_PRINTF() doesn't care about
precise value of ino, so with the change in this patch verifier is able
to prune states from after one of the branches, reducing number of total
states (and instructions) required for successful validation.
Similar principle applies to bigger real-world applications, just at
a much larger scale.
SELFTESTS
=========
File Program Insns (A) Insns (B) Insns (DIFF) States (A) States (B) States (DIFF)
--------------------------------------- ----------------------- --------- --------- --------------- ---------- ---------- -------------
bpf_iter_netlink.bpf.linked3.o dump_netlink 148 104 -44 (-29.73%) 8 5 -3 (-37.50%)
bpf_iter_unix.bpf.linked3.o dump_unix 8474 8404 -70 (-0.83%) 151 147 -4 (-2.65%)
bpf_loop.bpf.linked3.o stack_check 560 324 -236 (-42.14%) 42 24 -18 (-42.86%)
local_storage_bench.bpf.linked3.o get_local 120 77 -43 (-35.83%) 9 6 -3 (-33.33%)
loop6.bpf.linked3.o trace_virtqueue_add_sgs 10167 9868 -299 (-2.94%) 226 206 -20 (-8.85%)
pyperf600_bpf_loop.bpf.linked3.o on_event 4872 3423 -1449 (-29.74%) 322 229 -93 (-28.88%)
strobemeta.bpf.linked3.o on_event 180697 176036 -4661 (-2.58%) 4780 4734 -46 (-0.96%)
test_cls_redirect.bpf.linked3.o cls_redirect 65594 65401 -193 (-0.29%) 4230 4212 -18 (-0.43%)
test_global_func_args.bpf.linked3.o test_cls 145 136 -9 (-6.21%) 10 9 -1 (-10.00%)
test_l4lb.bpf.linked3.o balancer_ingress 4760 2612 -2148 (-45.13%) 113 102 -11 (-9.73%)
test_l4lb_noinline.bpf.linked3.o balancer_ingress 4845 4877 +32 (+0.66%) 219 221 +2 (+0.91%)
test_l4lb_noinline_dynptr.bpf.linked3.o balancer_ingress 2072 2087 +15 (+0.72%) 97 98 +1 (+1.03%)
test_seg6_loop.bpf.linked3.o __add_egr_x 12440 9975 -2465 (-19.82%) 364 353 -11 (-3.02%)
test_tcp_hdr_options.bpf.linked3.o estab 2558 2572 +14 (+0.55%) 179 180 +1 (+0.56%)
test_xdp_dynptr.bpf.linked3.o _xdp_tx_iptunnel 645 596 -49 (-7.60%) 26 24 -2 (-7.69%)
test_xdp_noinline.bpf.linked3.o balancer_ingress_v6 3520 3516 -4 (-0.11%) 216 216 +0 (+0.00%)
xdp_synproxy_kern.bpf.linked3.o syncookie_tc 82661 81241 -1420 (-1.72%) 5073 5155 +82 (+1.62%)
xdp_synproxy_kern.bpf.linked3.o syncookie_xdp 84964 82297 -2667 (-3.14%) 5130 5157 +27 (+0.53%)
META-INTERNAL
=============
Program Insns (A) Insns (B) Insns (DIFF) States (A) States (B) States (DIFF)
-------------------------------------- --------- --------- ----------------- ---------- ---------- ---------------
balancer_ingress 27925 23608 -4317 (-15.46%) 1488 1482 -6 (-0.40%)
balancer_ingress 31824 27546 -4278 (-13.44%) 1658 1652 -6 (-0.36%)
balancer_ingress 32213 27935 -4278 (-13.28%) 1689 1683 -6 (-0.36%)
balancer_ingress 32213 27935 -4278 (-13.28%) 1689 1683 -6 (-0.36%)
balancer_ingress 31824 27546 -4278 (-13.44%) 1658 1652 -6 (-0.36%)
balancer_ingress 38647 29562 -9085 (-23.51%) 2069 1835 -234 (-11.31%)
balancer_ingress 38647 29562 -9085 (-23.51%) 2069 1835 -234 (-11.31%)
balancer_ingress 40339 30792 -9547 (-23.67%) 2193 1934 -259 (-11.81%)
balancer_ingress 37321 29055 -8266 (-22.15%) 1972 1795 -177 (-8.98%)
balancer_ingress 38176 29753 -8423 (-22.06%) 2008 1831 -177 (-8.81%)
balancer_ingress 29193 20910 -8283 (-28.37%) 1599 1422 -177 (-11.07%)
balancer_ingress 30013 21452 -8561 (-28.52%) 1645 1447 -198 (-12.04%)
balancer_ingress 28691 24290 -4401 (-15.34%) 1545 1531 -14 (-0.91%)
balancer_ingress 34223 28965 -5258 (-15.36%) 1984 1875 -109 (-5.49%)
balancer_ingress 35481 26158 -9323 (-26.28%) 2095 1806 -289 (-13.79%)
balancer_ingress 35481 26158 -9323 (-26.28%) 2095 1806 -289 (-13.79%)
balancer_ingress 35868 26455 -9413 (-26.24%) 2140 1827 -313 (-14.63%)
balancer_ingress 35868 26455 -9413 (-26.24%) 2140 1827 -313 (-14.63%)
balancer_ingress 35481 26158 -9323 (-26.28%) 2095 1806 -289 (-13.79%)
balancer_ingress 35481 26158 -9323 (-26.28%) 2095 1806 -289 (-13.79%)
balancer_ingress 34844 29485 -5359 (-15.38%) 2036 1918 -118 (-5.80%)
fbflow_egress 3256 2652 -604 (-18.55%) 218 192 -26 (-11.93%)
fbflow_ingress 1026 944 -82 (-7.99%) 70 63 -7 (-10.00%)
sslwall_tc_egress 8424 7360 -1064 (-12.63%) 498 458 -40 (-8.03%)
syar_accept_protect 15040 9539 -5501 (-36.58%) 364 220 -144 (-39.56%)
syar_connect_tcp_v6 15036 9535 -5501 (-36.59%) 360 216 -144 (-40.00%)
syar_connect_udp_v4 15039 9538 -5501 (-36.58%) 361 217 -144 (-39.89%)
syar_connect_connect4_protect4 24805 15833 -8972 (-36.17%) 756 480 -276 (-36.51%)
syar_lsm_file_open 167772 151813 -15959 (-9.51%) 1836 1667 -169 (-9.20%)
syar_namespace_create_new 14805 9304 -5501 (-37.16%) 353 209 -144 (-40.79%)
syar_python3_detect 17531 12030 -5501 (-31.38%) 391 247 -144 (-36.83%)
syar_ssh_post_fork 16412 10911 -5501 (-33.52%) 405 261 -144 (-35.56%)
syar_enter_execve 14728 9227 -5501 (-37.35%) 345 201 -144 (-41.74%)
syar_enter_execveat 14728 9227 -5501 (-37.35%) 345 201 -144 (-41.74%)
syar_exit_execve 16622 11121 -5501 (-33.09%) 376 232 -144 (-38.30%)
syar_exit_execveat 16622 11121 -5501 (-33.09%) 376 232 -144 (-38.30%)
syar_syscalls_kill 15288 9787 -5501 (-35.98%) 398 254 -144 (-36.18%)
syar_task_enter_pivot_root 14898 9397 -5501 (-36.92%) 357 213 -144 (-40.34%)
syar_syscalls_setreuid 16678 11177 -5501 (-32.98%) 429 285 -144 (-33.57%)
syar_syscalls_setuid 16678 11177 -5501 (-32.98%) 429 285 -144 (-33.57%)
syar_syscalls_process_vm_readv 14959 9458 -5501 (-36.77%) 364 220 -144 (-39.56%)
syar_syscalls_process_vm_writev 15757 10256 -5501 (-34.91%) 390 246 -144 (-36.92%)
do_uprobe 15519 10018 -5501 (-35.45%) 373 229 -144 (-38.61%)
edgewall 179715 55783 -123932 (-68.96%) 12607 3999 -8608 (-68.28%)
bictcp_state 7570 4131 -3439 (-45.43%) 496 269 -227 (-45.77%)
cubictcp_state 7570 4131 -3439 (-45.43%) 496 269 -227 (-45.77%)
tcp_rate_skb_delivered 447 272 -175 (-39.15%) 29 18 -11 (-37.93%)
kprobe__bbr_set_state 4566 2615 -1951 (-42.73%) 209 124 -85 (-40.67%)
kprobe__bictcp_state 4566 2615 -1951 (-42.73%) 209 124 -85 (-40.67%)
inet_sock_set_state 1501 1337 -164 (-10.93%) 93 85 -8 (-8.60%)
tcp_retransmit_skb 1145 981 -164 (-14.32%) 67 59 -8 (-11.94%)
tcp_retransmit_synack 1183 951 -232 (-19.61%) 67 55 -12 (-17.91%)
bpf_tcptuner 1459 1187 -272 (-18.64%) 99 80 -19 (-19.19%)
tw_egress 801 776 -25 (-3.12%) 69 66 -3 (-4.35%)
tw_ingress 795 770 -25 (-3.14%) 69 66 -3 (-4.35%)
ttls_tc_ingress 19025 19383 +358 (+1.88%) 470 465 -5 (-1.06%)
ttls_nat_egress 490 299 -191 (-38.98%) 33 20 -13 (-39.39%)
ttls_nat_ingress 448 285 -163 (-36.38%) 32 21 -11 (-34.38%)
tw_twfw_egress 511127 212071 -299056 (-58.51%) 16733 8504 -8229 (-49.18%)
tw_twfw_ingress 500095 212069 -288026 (-57.59%) 16223 8504 -7719 (-47.58%)
tw_twfw_tc_eg 511113 212064 -299049 (-58.51%) 16732 8504 -8228 (-49.18%)
tw_twfw_tc_in 500095 212069 -288026 (-57.59%) 16223 8504 -7719 (-47.58%)
tw_twfw_egress 12632 12435 -197 (-1.56%) 276 260 -16 (-5.80%)
tw_twfw_ingress 12631 12454 -177 (-1.40%) 278 261 -17 (-6.12%)
tw_twfw_tc_eg 12595 12435 -160 (-1.27%) 274 259 -15 (-5.47%)
tw_twfw_tc_in 12631 12454 -177 (-1.40%) 278 261 -17 (-6.12%)
tw_xdp_dump 266 209 -57 (-21.43%) 9 8 -1 (-11.11%)
CILIUM
=========
File Program Insns (A) Insns (B) Insns (DIFF) States (A) States (B) States (DIFF)
------------- -------------------------------- --------- --------- ---------------- ---------- ---------- --------------
bpf_host.o cil_to_netdev 6047 4578 -1469 (-24.29%) 362 249 -113 (-31.22%)
bpf_host.o handle_lxc_traffic 2227 1585 -642 (-28.83%) 156 103 -53 (-33.97%)
bpf_host.o tail_handle_ipv4_from_netdev 2244 1458 -786 (-35.03%) 163 106 -57 (-34.97%)
bpf_host.o tail_handle_nat_fwd_ipv4 21022 10479 -10543 (-50.15%) 1289 670 -619 (-48.02%)
bpf_host.o tail_handle_nat_fwd_ipv6 15433 11375 -4058 (-26.29%) 905 643 -262 (-28.95%)
bpf_host.o tail_ipv4_host_policy_ingress 2219 1367 -852 (-38.40%) 161 96 -65 (-40.37%)
bpf_host.o tail_nodeport_nat_egress_ipv4 22460 19862 -2598 (-11.57%) 1469 1293 -176 (-11.98%)
bpf_host.o tail_nodeport_nat_ingress_ipv4 5526 3534 -1992 (-36.05%) 366 243 -123 (-33.61%)
bpf_host.o tail_nodeport_nat_ingress_ipv6 5132 4256 -876 (-17.07%) 241 219 -22 (-9.13%)
bpf_host.o tail_nodeport_nat_ipv6_egress 3702 3542 -160 (-4.32%) 215 205 -10 (-4.65%)
bpf_lxc.o tail_handle_nat_fwd_ipv4 21022 10479 -10543 (-50.15%) 1289 670 -619 (-48.02%)
bpf_lxc.o tail_handle_nat_fwd_ipv6 15433 11375 -4058 (-26.29%) 905 643 -262 (-28.95%)
bpf_lxc.o tail_ipv4_ct_egress 5073 3374 -1699 (-33.49%) 262 172 -90 (-34.35%)
bpf_lxc.o tail_ipv4_ct_ingress 5093 3385 -1708 (-33.54%) 262 172 -90 (-34.35%)
bpf_lxc.o tail_ipv4_ct_ingress_policy_only 5093 3385 -1708 (-33.54%) 262 172 -90 (-34.35%)
bpf_lxc.o tail_ipv6_ct_egress 4593 3878 -715 (-15.57%) 194 151 -43 (-22.16%)
bpf_lxc.o tail_ipv6_ct_ingress 4606 3891 -715 (-15.52%) 194 151 -43 (-22.16%)
bpf_lxc.o tail_ipv6_ct_ingress_policy_only 4606 3891 -715 (-15.52%) 194 151 -43 (-22.16%)
bpf_lxc.o tail_nodeport_nat_ingress_ipv4 5526 3534 -1992 (-36.05%) 366 243 -123 (-33.61%)
bpf_lxc.o tail_nodeport_nat_ingress_ipv6 5132 4256 -876 (-17.07%) 241 219 -22 (-9.13%)
bpf_overlay.o tail_handle_nat_fwd_ipv4 20524 10114 -10410 (-50.72%) 1271 638 -633 (-49.80%)
bpf_overlay.o tail_nodeport_nat_egress_ipv4 22718 19490 -3228 (-14.21%) 1475 1275 -200 (-13.56%)
bpf_overlay.o tail_nodeport_nat_ingress_ipv4 5526 3534 -1992 (-36.05%) 366 243 -123 (-33.61%)
bpf_overlay.o tail_nodeport_nat_ingress_ipv6 5132 4256 -876 (-17.07%) 241 219 -22 (-9.13%)
bpf_overlay.o tail_nodeport_nat_ipv6_egress 3638 3548 -90 (-2.47%) 209 203 -6 (-2.87%)
bpf_overlay.o tail_rev_nodeport_lb4 4368 3820 -548 (-12.55%) 248 215 -33 (-13.31%)
bpf_overlay.o tail_rev_nodeport_lb6 2867 2428 -439 (-15.31%) 167 140 -27 (-16.17%)
bpf_sock.o cil_sock6_connect 1718 1703 -15 (-0.87%) 100 99 -1 (-1.00%)
bpf_xdp.o tail_handle_nat_fwd_ipv4 12917 12443 -474 (-3.67%) 875 849 -26 (-2.97%)
bpf_xdp.o tail_handle_nat_fwd_ipv6 13515 13264 -251 (-1.86%) 715 702 -13 (-1.82%)
bpf_xdp.o tail_lb_ipv4 39492 36367 -3125 (-7.91%) 2430 2251 -179 (-7.37%)
bpf_xdp.o tail_lb_ipv6 80441 78058 -2383 (-2.96%) 3647 3523 -124 (-3.40%)
bpf_xdp.o tail_nodeport_ipv6_dsr 1038 901 -137 (-13.20%) 61 55 -6 (-9.84%)
bpf_xdp.o tail_nodeport_nat_egress_ipv4 13027 12096 -931 (-7.15%) 868 809 -59 (-6.80%)
bpf_xdp.o tail_nodeport_nat_ingress_ipv4 7617 5900 -1717 (-22.54%) 522 413 -109 (-20.88%)
bpf_xdp.o tail_nodeport_nat_ingress_ipv6 7575 7395 -180 (-2.38%) 383 374 -9 (-2.35%)
bpf_xdp.o tail_rev_nodeport_lb4 6808 6739 -69 (-1.01%) 403 396 -7 (-1.74%)
bpf_xdp.o tail_rev_nodeport_lb6 16173 15847 -326 (-2.02%) 1010 990 -20 (-1.98%)
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231205184248.1502704-9-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Andrii Nakryiko
|
add1cd7f22 |
selftests/bpf: validate zero preservation for sub-slot loads
Validate that 1-, 2-, and 4-byte loads from stack slots not aligned on 8-byte boundary still preserve zero, when loading from all-STACK_ZERO sub-slots, or when stack sub-slots are covered by spilled register with known constant zero value. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231205184248.1502704-8-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
e322f0bcb8 |
bpf: preserve constant zero when doing partial register restore
Similar to special handling of STACK_ZERO, when reading 1/2/4 bytes from stack from slot that has register spilled into it and that register has a constant value zero, preserve that zero and mark spilled register as precise for that. This makes spilled const zero register and STACK_ZERO cases equivalent in their behavior. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231205184248.1502704-7-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
b33ceb6a3d |
selftests/bpf: validate STACK_ZERO is preserved on subreg spill
Add tests validating that STACK_ZERO slots are preserved when slot is partially overwritten with subregister spill. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231205184248.1502704-6-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
eaf18febd6 |
bpf: preserve STACK_ZERO slots on partial reg spills
Instead of always forcing STACK_ZERO slots to STACK_MISC, preserve it in situations where this is possible. E.g., when spilling register as 1/2/4-byte subslots on the stack, all the remaining bytes in the stack slot do not automatically become unknown. If we knew they contained zeroes, we can preserve those STACK_ZERO markers. Add a helper mark_stack_slot_misc(), similar to scrub_spilled_slot(), but that doesn't overwrite either STACK_INVALID nor STACK_ZERO. Note that we need to take into account possibility of being in unprivileged mode, in which case STACK_INVALID is forced to STACK_MISC for correctness, as treating STACK_INVALID as equivalent STACK_MISC is only enabled in privileged mode. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231205184248.1502704-5-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
ab125ed3ec |
bpf: fix check for attempt to corrupt spilled pointer
When register is spilled onto a stack as a 1/2/4-byte register, we set
slot_type[BPF_REG_SIZE - 1] (plus potentially few more below it,
depending on actual spill size). So to check if some stack slot has
spilled register we need to consult slot_type[7], not slot_type[0].
To avoid the need to remember and double-check this in the future, just
use is_spilled_reg() helper.
Fixes:
|
||
|
Andrii Nakryiko
|
876301881c |
selftests/bpf: add stack access precision test
Add a new selftests that validates precision tracking for stack access instruction, using both r10-based and non-r10-based accesses. For non-r10 ones we also make sure to have non-zero var_off to validate that final stack offset is tracked properly in instruction history information inside verifier. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231205184248.1502704-3-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
41f6f64e69 |
bpf: support non-r10 register spill/fill to/from stack in precision tracking
Use instruction (jump) history to record instructions that performed register spill/fill to/from stack, regardless if this was done through read-only r10 register, or any other register after copying r10 into it *and* potentially adjusting offset. To make this work reliably, we push extra per-instruction flags into instruction history, encoding stack slot index (spi) and stack frame number in extra 10 bit flags we take away from prev_idx in instruction history. We don't touch idx field for maximum performance, as it's checked most frequently during backtracking. This change removes basically the last remaining practical limitation of precision backtracking logic in BPF verifier. It fixes known deficiencies, but also opens up new opportunities to reduce number of verified states, explored in the subsequent patches. There are only three differences in selftests' BPF object files according to veristat, all in the positive direction (less states). File Program Insns (A) Insns (B) Insns (DIFF) States (A) States (B) States (DIFF) -------------------------------------- ------------- --------- --------- ------------- ---------- ---------- ------------- test_cls_redirect_dynptr.bpf.linked3.o cls_redirect 2987 2864 -123 (-4.12%) 240 231 -9 (-3.75%) xdp_synproxy_kern.bpf.linked3.o syncookie_tc 82848 82661 -187 (-0.23%) 5107 5073 -34 (-0.67%) xdp_synproxy_kern.bpf.linked3.o syncookie_xdp 85116 84964 -152 (-0.18%) 5162 5130 -32 (-0.62%) Note, I avoided renaming jmp_history to more generic insn_hist to minimize number of lines changed and potential merge conflicts between bpf and bpf-next trees. Notice also cur_hist_entry pointer reset to NULL at the beginning of instruction verification loop. This pointer avoids the problem of relying on last jump history entry's insn_idx to determine whether we already have entry for current instruction or not. It can happen that we added jump history entry because current instruction is_jmp_point(), but also we need to add instruction flags for stack access. In this case, we don't want to entries, so we need to reuse last added entry, if it is present. Relying on insn_idx comparison has the same ambiguity problem as the one that was fixed recently in [0], so we avoid that. [0] https://patchwork.kernel.org/project/netdevbpf/patch/20231110002638.4168352-3-andrii@kernel.org/ Acked-by: Eduard Zingerman <eddyz87@gmail.com> Reported-by: Tao Lyu <tao.lyu@epfl.ch> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231205184248.1502704-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
 Stanislav Fomichev
|
5ffb260f75 |
selftests/bpf: Make sure we trigger metadata kfuncs for dst 8080
xdp_metadata test is flaky sometimes: verify_xsk_metadata:FAIL:rx_hash_type unexpected rx_hash_type: actual 8 != expected 0 Where 8 means XDP_RSS_TYPE_L4_ANY and is exported from veth driver only when 'skb->l4_hash' condition is met. This makes me think that the program is triggering again for some other packet. Let's have a filter, similar to xdp_hw_metadata, where we trigger XDP kfuncs only for UDP packets destined to port 8080. Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20231204174423.3460052-1-sdf@google.com |
||
|
Stanislav Fomichev
|
5c399ae080 |
xsk: Add missing SPDX to AF_XDP TX metadata documentation
Not sure how I missed that. I even acknowledged it explicitly
in the changelog [0]. Add the tag for real now.
[0] https://lore.kernel.org/bpf/20231127190319.1190813-1-sdf@google.com/
Fixes:
|
||
 Dave Marchevsky
|
1b4c7e20bf |
selftests/bpf: Test bpf_kptr_xchg stashing of bpf_rb_root
There was some confusion amongst Meta sched_ext folks regarding whether stashing bpf_rb_root - the tree itself, rather than a single node - was supported. This patch adds a small test which demonstrates this functionality: a local kptr with rb_root is created, a node is created and added to the tree, then the tree is kptr_xchg'd into a mapval. Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/bpf/20231204211722.571346-1-davemarchevsky@fb.com |
||
|
Alexei Starovoitov
|
ce3c49da11 |
Merge branch 'bpf-fix-the-release-of-inner-map'
Hou Tao says: ==================== bpf: Fix the release of inner map From: Hou Tao <houtao1@huawei.com> Hi, The patchset aims to fix the release of inner map in map array or map htab. The release of inner map is different with normal map. For normal map, the map is released after the bpf program which uses the map is destroyed, because the bpf program tracks the used maps. However bpf program can not track the used inner map because these inner map may be updated or deleted dynamically, and for now the ref-counter of inner map is decreased after the inner map is remove from outer map, so the inner map may be freed before the bpf program, which is accessing the inner map, exits and there will be use-after-free problem as demonstrated by patch #6. The patchset fixes the problem by deferring the release of inner map. The freeing of inner map is deferred according to the sleepable attributes of the bpf programs which own the outer map. Patch #1 fixes the warning when running the newly-added selftest under interpreter mode. Patch #2 adds more parameters to .map_fd_put_ptr() to prepare for the fix. Patch #3 fixes the incorrect value of need_defer when freeing the fd array. Patch #4 fixes the potential use-after-free problem by using call_rcu_tasks_trace() and call_rcu() to wait for one tasks trace RCU GP and one RCU GP unconditionally. Patch #5 optimizes the free of inner map by removing the unnecessary RCU GP waiting. Patch #6 adds a selftest to demonstrate the potential use-after-free problem. Patch #7 updates a selftest to update outer map in syscall bpf program. Please see individual patches for more details. And comments are always welcome. Change Log: v5: * patch #3: rename fd_array_map_delete_elem_with_deferred_free() to __fd_array_map_delete_elem() (Alexei) * patch #5: use atomic64_t instead of atomic_t to prevent potential overflow (Alexei) * patch #7: use ptr_to_u64() helper instead of force casting to initialize pointers in bpf_attr (Alexei) v4: https://lore.kernel.org/bpf/20231130140120.1736235-1-houtao@huaweicloud.com * patch #2: don't use "deferred", use "need_defer" uniformly * patch #3: newly-added, fix the incorrect value of need_defer during fd array free. * patch #4: doesn't consider the case in which bpf map is not used by any bpf program and only use sleepable_refcnt to remove unnecessary tasks trace RCU GP (Alexei) * patch #4: remove memory barriers added due to cautiousness (Alexei) v3: https://lore.kernel.org/bpf/20231124113033.503338-1-houtao@huaweicloud.com * multiple variable renamings (Martin) * define BPF_MAP_RCU_GP/BPF_MAP_RCU_TT_GP as bit (Martin) * use call_rcu() and its variants instead of synchronize_rcu() (Martin) * remove unnecessary mask in bpf_map_free_deferred() (Martin) * place atomic_or() and the related smp_mb() together (Martin) * add patch #6 to demonstrate that updating outer map in syscall program is dead-lock free (Alexei) * update comments about the memory barrier in bpf_map_fd_put_ptr() * update commit message for patch #3 and #4 to describe more details v2: https://lore.kernel.org/bpf/20231113123324.3914612-1-houtao@huaweicloud.com * defer the invocation of ops->map_free() instead of bpf_map_put() (Martin) * update selftest to make it being reproducible under JIT mode (Martin) * remove unnecessary preparatory patches v1: https://lore.kernel.org/bpf/20231107140702.1891778-1-houtao@huaweicloud.com ==================== Link: https://lore.kernel.org/r/20231204140425.1480317-1-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
 Hou Tao
|
e3dd408285 |
selftests/bpf: Test outer map update operations in syscall program
Syscall program is running with rcu_read_lock_trace being held, so if bpf_map_update_elem() or bpf_map_delete_elem() invokes synchronize_rcu_tasks_trace() when operating on an outer map, there will be dead-lock, so add a test to guarantee that it is dead-lock free. Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20231204140425.1480317-8-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Hou Tao
|
1624918be8 |
selftests/bpf: Add test cases for inner map
Add test cases to test the race between the destroy of inner map due to map-in-map update and the access of inner map in bpf program. The following 4 combinations are added: (1) array map in map array + bpf program (2) array map in map array + sleepable bpf program (3) array map in map htab + bpf program (4) array map in map htab + sleepable bpf program Before applying the fixes, when running `./test_prog -a map_in_map`, the following error was reported: ================================================================== BUG: KASAN: slab-use-after-free in array_map_update_elem+0x48/0x3e0 Read of size 4 at addr ffff888114f33824 by task test_progs/1858 CPU: 1 PID: 1858 Comm: test_progs Tainted: G O 6.6.0+ #7 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ...... Call Trace: <TASK> dump_stack_lvl+0x4a/0x90 print_report+0xd2/0x620 kasan_report+0xd1/0x110 __asan_load4+0x81/0xa0 array_map_update_elem+0x48/0x3e0 bpf_prog_be94a9f26772f5b7_access_map_in_array+0xe6/0xf6 trace_call_bpf+0x1aa/0x580 kprobe_perf_func+0xdd/0x430 kprobe_dispatcher+0xa0/0xb0 kprobe_ftrace_handler+0x18b/0x2e0 0xffffffffc02280f7 RIP: 0010:__x64_sys_getpgid+0x1/0x30 ...... </TASK> Allocated by task 1857: kasan_save_stack+0x26/0x50 kasan_set_track+0x25/0x40 kasan_save_alloc_info+0x1e/0x30 __kasan_kmalloc+0x98/0xa0 __kmalloc_node+0x6a/0x150 __bpf_map_area_alloc+0x141/0x170 bpf_map_area_alloc+0x10/0x20 array_map_alloc+0x11f/0x310 map_create+0x28a/0xb40 __sys_bpf+0x753/0x37c0 __x64_sys_bpf+0x44/0x60 do_syscall_64+0x36/0xb0 entry_SYSCALL_64_after_hwframe+0x6e/0x76 Freed by task 11: kasan_save_stack+0x26/0x50 kasan_set_track+0x25/0x40 kasan_save_free_info+0x2b/0x50 __kasan_slab_free+0x113/0x190 slab_free_freelist_hook+0xd7/0x1e0 __kmem_cache_free+0x170/0x260 kfree+0x9b/0x160 kvfree+0x2d/0x40 bpf_map_area_free+0xe/0x20 array_map_free+0x120/0x2c0 bpf_map_free_deferred+0xd7/0x1e0 process_one_work+0x462/0x990 worker_thread+0x370/0x670 kthread+0x1b0/0x200 ret_from_fork+0x3a/0x70 ret_from_fork_asm+0x1b/0x30 Last potentially related work creation: kasan_save_stack+0x26/0x50 __kasan_record_aux_stack+0x94/0xb0 kasan_record_aux_stack_noalloc+0xb/0x20 __queue_work+0x331/0x950 queue_work_on+0x75/0x80 bpf_map_put+0xfa/0x160 bpf_map_fd_put_ptr+0xe/0x20 bpf_fd_array_map_update_elem+0x174/0x1b0 bpf_map_update_value+0x2b7/0x4a0 __sys_bpf+0x2551/0x37c0 __x64_sys_bpf+0x44/0x60 do_syscall_64+0x36/0xb0 entry_SYSCALL_64_after_hwframe+0x6e/0x76 Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20231204140425.1480317-7-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Hou Tao
|
af66bfd3c8 |
bpf: Optimize the free of inner map
When removing the inner map from the outer map, the inner map will be freed after one RCU grace period and one RCU tasks trace grace period, so it is certain that the bpf program, which may access the inner map, has exited before the inner map is freed. However there is no need to wait for one RCU tasks trace grace period if the outer map is only accessed by non-sleepable program. So adding sleepable_refcnt in bpf_map and increasing sleepable_refcnt when adding the outer map into env->used_maps for sleepable program. Although the max number of bpf program is INT_MAX - 1, the number of bpf programs which are being loaded may be greater than INT_MAX, so using atomic64_t instead of atomic_t for sleepable_refcnt. When removing the inner map from the outer map, using sleepable_refcnt to decide whether or not a RCU tasks trace grace period is needed before freeing the inner map. Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20231204140425.1480317-6-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Hou Tao
|
8766733641 |
bpf: Defer the free of inner map when necessary
When updating or deleting an inner map in map array or map htab, the map may still be accessed by non-sleepable program or sleepable program. However bpf_map_fd_put_ptr() decreases the ref-counter of the inner map directly through bpf_map_put(), if the ref-counter is the last one (which is true for most cases), the inner map will be freed by ops->map_free() in a kworker. But for now, most .map_free() callbacks don't use synchronize_rcu() or its variants to wait for the elapse of a RCU grace period, so after the invocation of ops->map_free completes, the bpf program which is accessing the inner map may incur use-after-free problem. Fix the free of inner map by invoking bpf_map_free_deferred() after both one RCU grace period and one tasks trace RCU grace period if the inner map has been removed from the outer map before. The deferment is accomplished by using call_rcu() or call_rcu_tasks_trace() when releasing the last ref-counter of bpf map. The newly-added rcu_head field in bpf_map shares the same storage space with work field to reduce the size of bpf_map. Fixes: |
||
|
Hou Tao
|
79d93b3c6f |
bpf: Set need_defer as false when clearing fd array during map free
Both map deletion operation, map release and map free operation use fd_array_map_delete_elem() to remove the element from fd array and need_defer is always true in fd_array_map_delete_elem(). For the map deletion operation and map release operation, need_defer=true is necessary, because the bpf program, which accesses the element in fd array, may still alive. However for map free operation, it is certain that the bpf program which owns the fd array has already been exited, so setting need_defer as false is appropriate for map free operation. So fix it by adding need_defer parameter to bpf_fd_array_map_clear() and adding a new helper __fd_array_map_delete_elem() to handle the map deletion, map release and map free operations correspondingly. Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20231204140425.1480317-4-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Hou Tao
|
20c20bd11a |
bpf: Add map and need_defer parameters to .map_fd_put_ptr()
map is the pointer of outer map, and need_defer needs some explanation. need_defer tells the implementation to defer the reference release of the passed element and ensure that the element is still alive before the bpf program, which may manipulate it, exits. The following three cases will invoke map_fd_put_ptr() and different need_defer values will be passed to these callers: 1) release the reference of the old element in the map during map update or map deletion. The release must be deferred, otherwise the bpf program may incur use-after-free problem, so need_defer needs to be true. 2) release the reference of the to-be-added element in the error path of map update. The to-be-added element is not visible to any bpf program, so it is OK to pass false for need_defer parameter. 3) release the references of all elements in the map during map release. Any bpf program which has access to the map must have been exited and released, so need_defer=false will be OK. These two parameters will be used by the following patches to fix the potential use-after-free problem for map-in-map. Signed-off-by: Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20231204140425.1480317-3-houtao@huaweicloud.com Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Hou Tao
|
169410eba2 |
bpf: Check rcu_read_lock_trace_held() before calling bpf map helpers
These three bpf_map_{lookup,update,delete}_elem() helpers are also
available for sleepable bpf program, so add the corresponding lock
assertion for sleepable bpf program, otherwise the following warning
will be reported when a sleepable bpf program manipulates bpf map under
interpreter mode (aka bpf_jit_enable=0):
WARNING: CPU: 3 PID: 4985 at kernel/bpf/helpers.c:40 ......
CPU: 3 PID: 4985 Comm: test_progs Not tainted 6.6.0+ #2
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) ......
RIP: 0010:bpf_map_lookup_elem+0x54/0x60
......
Call Trace:
<TASK>
? __warn+0xa5/0x240
? bpf_map_lookup_elem+0x54/0x60
? report_bug+0x1ba/0x1f0
? handle_bug+0x40/0x80
? exc_invalid_op+0x18/0x50
? asm_exc_invalid_op+0x1b/0x20
? __pfx_bpf_map_lookup_elem+0x10/0x10
? rcu_lockdep_current_cpu_online+0x65/0xb0
? rcu_is_watching+0x23/0x50
? bpf_map_lookup_elem+0x54/0x60
? __pfx_bpf_map_lookup_elem+0x10/0x10
___bpf_prog_run+0x513/0x3b70
__bpf_prog_run32+0x9d/0xd0
? __bpf_prog_enter_sleepable_recur+0xad/0x120
? __bpf_prog_enter_sleepable_recur+0x3e/0x120
bpf_trampoline_6442580665+0x4d/0x1000
__x64_sys_getpgid+0x5/0x30
? do_syscall_64+0x36/0xb0
entry_SYSCALL_64_after_hwframe+0x6e/0x76
</TASK>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231204140425.1480317-2-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
 Colin Ian King
|
153de60e8b |
selftests/bpf: Fix spelling mistake "get_signaure_size" -> "get_signature_size"
There is a spelling mistake in an ASSERT_GT message. Fix it. Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20231204093940.2611954-1-colin.i.king@gmail.com |
||
 Andrei Matei
|
5bd90cdc65 |
bpf: Minor logging improvement
One place where we were logging a register was only logging the variable part, not also the fixed part. Signed-off-by: Andrei Matei <andreimatei1@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20231204011248.2040084-1-andreimatei1@gmail.com |
||
|
Alexei Starovoitov
|
90679706d4 |
Merge branch 'bpf-verifier-retval-logic-fixes'
Andrii Nakryiko says: ==================== BPF verifier retval logic fixes This patch set fixes BPF verifier logic around validating and enforcing return values for BPF programs that have specific range of expected return values. Both sync and async callbacks have similar logic and are fixes as well. A few tests are added that would fail without the fixes in this patch set. Also, while at it, we update retval checking logic to use smin/smax range instead of tnum, avoiding future potential issues if expected range cannot be represented precisely by tnum (e.g., [0, 2] is not representable by tnum and is treated as [0, 3]). There is a little bit of refactoring to unify async callback and program exit logic to avoid duplication of checks as much as possible. v4->v5: - fix timer_bad_ret test on no-alu32 flavor (CI); v3->v4: - add back bpf_func_state rearrangement patch; - simplified patch #4 as suggested (Shung-Hsi); v2->v3: - more carefullly switch from umin/umax to smin/smax; v1->v2: - drop tnum from retval checks (Eduard); - use smin/smax instead of umin/umax (Alexei). ==================== Link: https://lore.kernel.org/r/20231202175705.885270-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
81eff2e364 |
bpf: simplify tnum output if a fully known constant
Emit tnum representation as just a constant if all bits are known. Use decimal-vs-hex logic to determine exact format of emitted constant value, just like it's done for register range values. For that move tnum_strn() to kernel/bpf/log.c to reuse decimal-vs-hex determination logic and constants. Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231202175705.885270-12-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
5c19e1d05e |
selftests/bpf: adjust global_func15 test to validate prog exit precision
Add one more subtest to global_func15 selftest to validate that verifier properly marks r0 as precise and avoids erroneous state pruning of the branch that has return value outside of expected [0, 1] value. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231202175705.885270-11-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
e02dea158d |
selftests/bpf: validate async callback return value check correctness
Adjust timer/timer_ret_1 test to validate more carefully verifier logic of enforcing async callback return value. This test will pass only if return result is marked precise and read. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231202175705.885270-10-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
eabe518de5 |
bpf: enforce precision of R0 on program/async callback return
Given we enforce a valid range for program and async callback return
value, we must mark R0 as precise to avoid incorrect state pruning.
Fixes:
|
||
|
Andrii Nakryiko
|
0ef24c8dfa |
bpf: unify async callback and program retval checks
Use common logic to verify program return values and async callback return values. This allows to avoid duplication of any extra steps necessary, like precision marking, which will be added in the next patch. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231202175705.885270-8-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
c871d0e00f |
bpf: enforce precise retval range on program exit
Similarly to subprog/callback logic, enforce return value of BPF program using more precise smin/smax range. We need to adjust a bunch of tests due to a changed format of an error message. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231202175705.885270-7-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
60a6b2c78c |
selftests/bpf: add selftest validating callback result is enforced
BPF verifier expects callback subprogs to return values from specified range (typically [0, 1]). This requires that r0 at exit is both precise (because we rely on specific value range) and is marked as read (otherwise state comparison will ignore such register as unimportant). Add a simple test that validates that all these conditions are enforced. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231202175705.885270-6-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
8fa4ecd49b |
bpf: enforce exact retval range on subprog/callback exit
Instead of relying on potentially imprecise tnum representation of expected return value range for callbacks and subprogs, validate that smin/smax range satisfy exact expected range of return values. E.g., if callback would need to return [0, 2] range, tnum can't represent this precisely and instead will allow [0, 3] range. By checking smin/smax range, we can make sure that subprog/callback indeed returns only valid [0, 2] range. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231202175705.885270-5-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
0acd03a5bd |
bpf: enforce precision of R0 on callback return
Given verifier checks actual value, r0 has to be precise, so we need to
propagate precision properly. r0 also has to be marked as read,
otherwise subsequent state comparisons will ignore such register as
unimportant and precision won't really help here.
Fixes:
|
||
|
Andrii Nakryiko
|
5fad52bee3 |
bpf: provide correct register name for exception callback retval check
bpf_throw() is checking R1, so let's report R1 in the log. Acked-by: Eduard Zingerman <eddyz87@gmail.com> Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20231202175705.885270-3-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org> |
||
|
Andrii Nakryiko
|
45b5623f2d |
bpf: rearrange bpf_func_state fields to save a bit of memory
It's a trivial rearrangement saving 8 bytes. We have 4 bytes of padding
at the end which can be filled with another field without increasing
struct bpf_func_state.
copy_func_state() logic remains correct without any further changes.
BEFORE
======
struct bpf_func_state {
struct bpf_reg_state regs[11]; /* 0 1320 */
/* --- cacheline 20 boundary (1280 bytes) was 40 bytes ago --- */
int callsite; /* 1320 4 */
u32 frameno; /* 1324 4 */
u32 subprogno; /* 1328 4 */
u32 async_entry_cnt; /* 1332 4 */
bool in_callback_fn; /* 1336 1 */
/* XXX 7 bytes hole, try to pack */
/* --- cacheline 21 boundary (1344 bytes) --- */
struct tnum callback_ret_range; /* 1344 16 */
bool in_async_callback_fn; /* 1360 1 */
bool in_exception_callback_fn; /* 1361 1 */
/* XXX 2 bytes hole, try to pack */
int acquired_refs; /* 1364 4 */
struct bpf_reference_state * refs; /* 1368 8 */
int allocated_stack; /* 1376 4 */
/* XXX 4 bytes hole, try to pack */
struct bpf_stack_state * stack; /* 1384 8 */
/* size: 1392, cachelines: 22, members: 13 */
/* sum members: 1379, holes: 3, sum holes: 13 */
/* last cacheline: 48 bytes */
};
AFTER
=====
struct bpf_func_state {
struct bpf_reg_state regs[11]; /* 0 1320 */
/* --- cacheline 20 boundary (1280 bytes) was 40 bytes ago --- */
int callsite; /* 1320 4 */
u32 frameno; /* 1324 4 */
u32 subprogno; /* 1328 4 */
u32 async_entry_cnt; /* 1332 4 */
struct tnum callback_ret_range; /* 1336 16 */
/* --- cacheline 21 boundary (1344 bytes) was 8 bytes ago --- */
bool in_callback_fn; /* 1352 1 */
bool in_async_callback_fn; /* 1353 1 */
bool in_exception_callback_fn; /* 1354 1 */
/* XXX 1 byte hole, try to pack */
int acquired_refs; /* 1356 4 */
struct bpf_reference_state * refs; /* 1360 8 */
struct bpf_stack_state * stack; /* 1368 8 */
int allocated_stack; /* 1376 4 */
/* size: 1384, cachelines: 22, members: 13 */
/* sum members: 1379, holes: 1, sum holes: 1 */
/* padding: 4 */
/* last cacheline: 40 bytes */
};
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231202175705.885270-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|
||
|
Alexei Starovoitov
|
6685aadcab |
Merge branch 'bpf-file-verification-with-lsm-and-fsverity'
Song Liu says:
====================
bpf: File verification with LSM and fsverity
Changes v14 => v15:
1. Fix selftest build without CONFIG_FS_VERITY. (Alexei)
2. Add Acked-by from KP.
Changes v13 => v14:
1. Add "static" for bpf_fs_kfunc_set.
2. Add Acked-by from Christian Brauner.
Changes v12 => v13:
1. Only keep 4/9 through 9/9 of v12, as the first 3 patches already
applied;
2. Use new macro __bpf_kfunc_[start|end]_defs().
Changes v11 => v12:
1. Fix typo (data_ptr => sig_ptr) in bpf_get_file_xattr().
Changes v10 => v11:
1. Let __bpf_dynptr_data() return const void *. (Andrii)
2. Optimize code to reuse output from __bpf_dynptr_size(). (Andrii)
3. Add __diag_ignore_all("-Wmissing-declarations") for kfunc definition.
4. Fix an off indentation. (Andrii)
Changes v9 => v10:
1. Remove WARN_ON_ONCE() from check_reg_const_str. (Alexei)
Changes v8 => v9:
1. Fix test_progs kfunc_dynptr_param/dynptr_data_null.
Changes v7 => v8:
1. Do not use bpf_dynptr_slice* in the kernel. Add __bpf_dynptr_data* and
use them in ther kernel. (Andrii)
Changes v6 => v7:
1. Change "__const_str" annotation to "__str". (Alexei, Andrii)
2. Add KF_TRUSTED_ARGS flag for both new kfuncs. (KP)
3. Only allow bpf_get_file_xattr() to read xattr with "user." prefix.
4. Add Acked-by from Eric Biggers.
Changes v5 => v6:
1. Let fsverity_init_bpf() return void. (Eric Biggers)
2. Sort things in alphabetic orders. (Eric Biggers)
Changes v4 => v5:
1. Revise commit logs. (Alexei)
Changes v3 => v4:
1. Fix error reported by CI.
2. Update comments of bpf_dynptr_slice* that they may return error pointer.
Changes v2 => v3:
1. Rebase and resolve conflicts.
Changes v1 => v2:
1. Let bpf_get_file_xattr() use const string for arg "name". (Alexei)
2. Add recursion prevention with allowlist. (Alexei)
3. Let bpf_get_file_xattr() use __vfs_getxattr() to avoid recursion,
as vfs_getxattr() calls into other LSM hooks.
4. Do not use dynptr->data directly, use helper insteadd. (Andrii)
5. Fixes with bpf_get_fsverity_digest. (Eric Biggers)
6. Add documentation. (Eric Biggers)
7. Fix some compile warnings. (kernel test robot)
This set enables file verification with BPF LSM and fsverity.
In this solution, fsverity is used to provide reliable and efficient hash
of files; and BPF LSM is used to implement signature verification (against
asymmetric keys), and to enforce access control.
This solution can be used to implement access control in complicated cases.
For example: only signed python binary and signed python script and access
special files/devices/ports.
Thanks,
Song
====================
Link: https://lore.kernel.org/r/20231129234417.856536-1-song@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
|