[ Upstream commit a6bded921e ]
Explicit fixed file install/remove operations on slots outside the
configured alloc range can corrupt alloc_hint via io_file_bitmap_set()
and io_file_bitmap_clear(), which unconditionally update alloc_hint to
the bit position. This causes subsequent auto-allocations to fall
outside the configured range.
For example, if the alloc range is [10, 20) and a file is removed at
slot 2, alloc_hint gets set to 2. The next auto-alloc then starts
searching from slot 2, potentially returning a slot below the range.
Fix this by clamping alloc_hint to [file_alloc_start, file_alloc_end)
at the top of io_file_bitmap_get() before starting the search.
Cc: stable@vger.kernel.org
Fixes: 6e73dffbb9 ("io_uring: let to set a range for file slot allocation")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 806ae939c4 ]
If a send bundle has picked a bunch of buffers, then it needs to send
all of those to be complete. This may require poll arming, if the send
buffer ends up being full. Once a send bundle has been poll armed, no
further bundles should be attempted.
This allows a current bundle to complete even though it needs to go
through polling to do so, but it will not allow another bundle to be
started once that has happened. Ideally we would abort a bundle if it
was only partially sent, but as some parts of it already went out on the
wire, this obviously isn't feasible. Not continuing more bundle attempts
post encountering a full socket buffer is the second best thing.
Cc: stable@vger.kernel.org
Fixes: a05d1f625c ("io_uring/net: support bundles for send")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 22dbb0987b ]
By having them share the same space in struct io_cancel_data, it ends up
disallowing IORING_ASYNC_CANCEL_FD|IORING_ASYNC_CANCEL_USERDATA from
working. Eg you cannot match on both a file and user_data for
cancelation purposes. This obviously isn't a common use case as nobody
has reported this, but it does result in -ENOENT potentially being
returned when trying to match on both, rather than actually doing what
the API says it would.
Fixes: 4bf94615b8 ("io_uring: allow IORING_OP_ASYNC_CANCEL with 'fd' key")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 649dd18f55 ]
Check if the passed in offset is negative once cast to sync->off. This
ensures that -EINVAL is returned for that case, like it would be for
sync_file_range(2).
Fixes: c992fe2925 ("io_uring: add fsync support")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7a8737e113 ]
io_uring_enter(), __io_msg_ring_data(), and io_msg_send_fd() read
ctx->flags and ctx->submitter_task without holding the ctx's uring_lock.
This means they may race with the assignment to ctx->submitter_task and
the clearing of IORING_SETUP_R_DISABLED from ctx->flags in
io_register_enable_rings(). Ensure the correct ordering of the
ctx->flags and ctx->submitter_task memory accesses by storing to
ctx->flags using release ordering and loading it using acquire ordering.
Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Fixes: 4add705e4e ("io_uring: remove io_register_submitter")
Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Commit d8e1dec2f8 upstream.
The mshot side of reads already does this, but the regular read path
does not. This leads to needing recycling checks sprinkled in various
spots in the "go async" path, like arming poll. In preparation for
getting rid of those, ensure that read recycles appropriately.
Link: https://lore.kernel.org/r/20250821020750.598432-8-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 10dc959398 upstream.
Currently this is checked before running the pending work. Normally this
is quite fine, as work items either end up blocking (which will create a
new worker for other items), or they complete fairly quickly. But syzbot
reports an issue where io-wq takes seemingly forever to exit, and with a
bit of debugging, this turns out to be because it queues a bunch of big
(2GB - 4096b) reads with a /dev/msr* file. Since this file type doesn't
support ->read_iter(), loop_rw_iter() ends up handling them. Each read
returns 16MB of data read, which takes 20 (!!) seconds. With a bunch of
these pending, processing the whole chain can take a long time. Easily
longer than the syzbot uninterruptible sleep timeout of 140 seconds.
This then triggers a complaint off the io-wq exit path:
INFO: task syz.4.135:6326 blocked for more than 143 seconds.
Not tainted syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.135 state:D stack:26824 pid:6326 tgid:6324 ppid:5957 task_flags:0x400548 flags:0x00080000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common+0x2fc/0x4e0 kernel/sched/completion.c:121
io_wq_exit_workers io_uring/io-wq.c:1328 [inline]
io_wq_put_and_exit+0x271/0x8a0 io_uring/io-wq.c:1356
io_uring_clean_tctx+0x10d/0x190 io_uring/tctx.c:203
io_uring_cancel_generic+0x69c/0x9a0 io_uring/cancel.c:651
io_uring_files_cancel include/linux/io_uring.h:19 [inline]
do_exit+0x2ce/0x2bd0 kernel/exit.c:911
do_group_exit+0xd3/0x2a0 kernel/exit.c:1112
get_signal+0x2671/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa02738f749
RSP: 002b:00007fa0281ae0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fa0275e6098 RCX: 00007fa02738f749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fa0275e6098
RBP: 00007fa0275e6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa0275e6128 R14: 00007fff14e4fcb0 R15: 00007fff14e4fd98
There's really nothing wrong here, outside of processing these reads
will take a LONG time. However, we can speed up the exit by checking the
IO_WQ_BIT_EXIT inside the io_worker_handle_work() loop, as syzbot will
exit the ring after queueing up all of these reads. Then once the first
item is processed, io-wq will simply cancel the rest. That should avoid
syzbot running into this complaint again.
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/68a2decc.050a0220.e29e5.0099.GAE@google.com/
Reported-by: syzbot+4eb282331cab6d5b6588@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit da579f05ef upstream.
With IORING_SETUP_DEFER_TASKRUN, task work is queued to ctx->work_llist
(local work) rather than the fallback list. During io_ring_exit_work(),
io_move_task_work_from_local() was called once before the cancel loop,
moving work from work_llist to fallback_llist.
However, task work can be added to work_llist during the cancel loop
itself. There are two cases:
1) io_kill_timeouts() is called from io_uring_try_cancel_requests() to
cancel pending timeouts, and it adds task work via io_req_queue_tw_complete()
for each cancelled timeout:
2) URING_CMD requests like ublk can be completed via
io_uring_cmd_complete_in_task() from ublk_queue_rq() during canceling,
given ublk request queue is only quiesced when canceling the 1st uring_cmd.
Since io_allowed_defer_tw_run() returns false in io_ring_exit_work()
(kworker != submitter_task), io_run_local_work() is never invoked,
and the work_llist entries are never processed. This causes
io_uring_try_cancel_requests() to loop indefinitely, resulting in
100% CPU usage in kworker threads.
Fix this by moving io_move_task_work_from_local() inside the cancel
loop, ensuring any work on work_llist is moved to fallback before
each cancel attempt.
Cc: stable@vger.kernel.org
Fixes: c0e0d6ba25 ("io_uring: add IORING_SETUP_DEFER_TASKRUN")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit e15cb2200b upstream.
Using min_wait, two timeouts are given:
1) The min_wait timeout, within which up to 'wait_nr' events are
waited for.
2) The overall long timeout, which is entered if no events are generated
in the min_wait window.
If the min_wait has expired, any event being posted must wake the task.
For SQPOLL, that isn't the case, as it won't trigger the io_has_work()
condition, as it will have already processed the task_work that happened
when an event was posted. This causes any event to trigger post the
min_wait to not always cause the waiting application to wakeup, and
instead it will wait until the overall timeout has expired. This can be
shown in a test case that has a 1 second min_wait, with a 5 second
overall wait, even if an event triggers after 1.5 seconds:
axboe@m2max-kvm /d/iouring-mre (master)> zig-out/bin/iouring
info: MIN_TIMEOUT supported: true, features: 0x3ffff
info: Testing: min_wait=1000ms, timeout=5s, wait_nr=4
info: 1 cqes in 5000.2ms
where the expected result should be:
axboe@m2max-kvm /d/iouring-mre (master)> zig-out/bin/iouring
info: MIN_TIMEOUT supported: true, features: 0x3ffff
info: Testing: min_wait=1000ms, timeout=5s, wait_nr=4
info: 1 cqes in 1500.3ms
When the min_wait timeout triggers, reset the number of completions
needed to wake the task. This should ensure that any future events will
wake the task, regardless of how many events it originally wanted to
wait for.
Reported-by: Tip ten Brink <tip@tenbrinkmeijs.com>
Cc: stable@vger.kernel.org
Fixes: 1100c4a265 ("io_uring: add support for batch wait timeout")
Link: https://github.com/axboe/liburing/issues/1477
Signed-off-by: Jens Axboe <axboe@kernel.dk>
(cherry picked from commit e15cb2200b)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 84230ad2d2 upstream.
When the core of io_uring was updated to handle completions
consistently and with fixed return codes, the POLL_REMOVE opcode
with updates got slightly broken. If a POLL_ADD is pending and
then POLL_REMOVE is used to update the events of that request, if that
update causes the POLL_ADD to now trigger, then that completion is lost
and a CQE is never posted.
Additionally, ensure that if an update does cause an existing POLL_ADD
to complete, that the completion value isn't always overwritten with
-ECANCELED. For that case, whatever io_poll_add() set the value to
should just be retained.
Cc: stable@vger.kernel.org
Fixes: 97b388d70b ("io_uring: handle completions in the core")
Reported-by: syzbot+641eec6b7af1f62f2b99@syzkaller.appspotmail.com
Tested-by: syzbot+641eec6b7af1f62f2b99@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b14fad5553 upstream.
__io_openat_prep() allocates a struct filename using getname(). However,
for the condition of the file being installed in the fixed file table as
well as having O_CLOEXEC flag set, the function returns early. At that
point, the request doesn't have REQ_F_NEED_CLEANUP flag set. Due to this,
the memory for the newly allocated struct filename is not cleaned up,
causing a memory leak.
Fix this by setting the REQ_F_NEED_CLEANUP for the request just after the
successful getname() call, so that when the request is torn down, the
filename will be cleaned up, along with other resources needing cleanup.
Reported-by: syzbot+00e61c43eb5e4740438f@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=00e61c43eb5e4740438f
Tested-by: syzbot+00e61c43eb5e4740438f@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Prithvi Tambewagh <activprithvi@gmail.com>
Fixes: b9445598d8 ("io_uring: openat directly into fixed fd table")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit a94e065726 upstream.
The current approach is a bit naive, and hence calls the time querying
way too often. Only start the "doing work" timer when there's actual
work to do, and then use that information to terminate (and account) the
work time once done. This greatly reduces the frequency of these calls,
when they cannot have changed anyway.
Running a basic random reader that is setup to use SQPOLL, a profile
before this change shows these as the top cycle consumers:
+ 32.60% iou-sqp-1074 [kernel.kallsyms] [k] thread_group_cputime_adjusted
+ 19.97% iou-sqp-1074 [kernel.kallsyms] [k] thread_group_cputime
+ 12.20% io_uring io_uring [.] submitter_uring_fn
+ 4.13% iou-sqp-1074 [kernel.kallsyms] [k] getrusage
+ 2.45% iou-sqp-1074 [kernel.kallsyms] [k] io_submit_sqes
+ 2.18% iou-sqp-1074 [kernel.kallsyms] [k] __pi_memset_generic
+ 2.09% iou-sqp-1074 [kernel.kallsyms] [k] cputime_adjust
and after this change, top of profile looks as follows:
+ 36.23% io_uring io_uring [.] submitter_uring_fn
+ 23.26% iou-sqp-819 [kernel.kallsyms] [k] io_sq_thread
+ 10.14% iou-sqp-819 [kernel.kallsyms] [k] io_sq_tw
+ 6.52% iou-sqp-819 [kernel.kallsyms] [k] tctx_task_work_run
+ 4.82% iou-sqp-819 [kernel.kallsyms] [k] nvme_submit_cmds.part.0
+ 2.91% iou-sqp-819 [kernel.kallsyms] [k] io_submit_sqes
[...]
0.02% iou-sqp-819 [kernel.kallsyms] [k] cputime_adjust
where it's spending the cycles on things that actually matter.
Reported-by: Fengnan Chang <changfengnan@bytedance.com>
Cc: stable@vger.kernel.org
Fixes: 3fcb9d1720 ("io_uring/sqpoll: statistics of the true utilization of sq threads")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 8ac9b0d33e upstream.
getrusage() does a lot more than what the SQPOLL accounting needs, the
latter only cares about (and uses) the stime. Rather than do a full
RUSAGE_SELF summation, just query the used stime instead.
Cc: stable@vger.kernel.org
Fixes: 3fcb9d1720 ("io_uring/sqpoll: statistics of the true utilization of sq threads")
Reviewed-by: Gabriel Krisman Bertazi <krisman@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit c5efc6a0b3 ]
The __must_hold annotation references &req->ctx->uring_lock, but req
is not in scope in io_install_fixed_file. This change updates the
annotation to reference the correct ctx->uring_lock.
improving code clarity.
Fixes: f110ed8498 ("io_uring: split out fixed file installation and removal")
Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Commit 927069c4ac upstream.
This reverts commit 90bfb28d5f.
Kevin reports that this commit causes an issue for him with LVM
snapshots, most likely because of turning off NOWAIT support while a
snapshot is being created. This makes -EOPNOTSUPP bubble back through
the completion handler, where io_uring read/write handling should just
retry it.
Reinstate the previous check removed by the referenced commit.
Cc: stable@vger.kernel.org
Fixes: 90bfb28d5f ("io_uring/rw: drop -EOPNOTSUPP check in __io_complete_rw_common()")
Reported-by: Salvatore Bonaccorso <carnil@debian.org>
Reported-by: Kevin Lumik <kevin@xf.ee>
Link: https://lore.kernel.org/io-uring/cceb723c-051b-4de2-9a4c-4aa82e1619ee@kernel.dk/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 2c139a47ef ]
In io_link_skb function, there is a bug where prev_notif is incorrectly
assigned using 'nd' instead of 'prev_nd'. This causes the context
validation check to compare the current notification with itself instead
of comparing it with the previous notification.
Fix by using the correct prev_nd parameter when obtaining prev_notif.
Signed-off-by: Yang Xiuwei <yangxiuwei@kylinos.cn>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Fixes: 6fe4220912 ("io_uring/notif: implement notification stacking")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Partially based on commit 98b6fa62c8 upstream.
This can be triggered by userspace, so just drop it. The condition
is appropriately handled.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit df8922afc3 upstream.
A recent commit:
fc582cd26e ("io_uring/msg_ring: ensure io_kiocb freeing is deferred for RCU")
fixed an issue with not deferring freeing of io_kiocb structs that
msg_ring allocates to after the current RCU grace period. But this only
covers requests that don't end up in the allocation cache. If a request
goes into the alloc cache, it can get reused before it is sane to do so.
A recent syzbot report would seem to indicate that there's something
there, however it may very well just be because of the KASAN poisoning
that the alloc_cache handles manually.
Rather than attempt to make the alloc_cache sane for that use case, just
drop the usage of the alloc_cache for msg_ring request payload data.
Fixes: 50cf5f3842 ("io_uring/msg_ring: add an alloc cache for io_kiocb entries")
Link: https://lore.kernel.org/io-uring/68cc2687.050a0220.139b6.0005.GAE@google.com/
Reported-by: syzbot+baa2e0f4e02df602583e@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 3539b1467e upstream.
When running task_work for an exiting task, rather than perform the
issue retry attempt, the task_work is canceled. However, this isn't
done for a ring that has been closed. This can lead to requests being
successfully completed post the ring being closed, which is somewhat
confusing and surprising to an application.
Rather than just check the task exit state, also include the ring
ref state in deciding whether or not to terminate a given request when
run from task_work.
Cc: stable@vger.kernel.org # 6.1+
Link: https://github.com/axboe/liburing/discussions/1459
Reported-by: Benedek Thaler <thaler@thaler.hu>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Parts of commit b6f58a3f4a upstream.
Backport io_should_terminate_tw() helper to judge whether task_work
should be run or terminated.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit df3b8ca604 upstream.
When the taks that submitted a request is dying, a task work for that
request might get run by a kernel thread or even worse by a half
dismantled task. We can't just cancel the task work without running the
callback as the cmd might need to do some clean up, so pass a flag
instead. If set, it's not safe to access any task resources and the
callback is expected to cancel the cmd ASAP.
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit fc582cd26e upstream.
syzbot reports that defer/local task_work adding via msg_ring can hit
a request that has been freed:
CPU: 1 UID: 0 PID: 19356 Comm: iou-wrk-19354 Not tainted 6.16.0-rc4-syzkaller-00108-g17bbde2e1716 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:408 [inline]
print_report+0xd2/0x2b0 mm/kasan/report.c:521
kasan_report+0x118/0x150 mm/kasan/report.c:634
io_req_local_work_add io_uring/io_uring.c:1184 [inline]
__io_req_task_work_add+0x589/0x950 io_uring/io_uring.c:1252
io_msg_remote_post io_uring/msg_ring.c:103 [inline]
io_msg_data_remote io_uring/msg_ring.c:133 [inline]
__io_msg_ring_data+0x820/0xaa0 io_uring/msg_ring.c:151
io_msg_ring_data io_uring/msg_ring.c:173 [inline]
io_msg_ring+0x134/0xa00 io_uring/msg_ring.c:314
__io_issue_sqe+0x17e/0x4b0 io_uring/io_uring.c:1739
io_issue_sqe+0x165/0xfd0 io_uring/io_uring.c:1762
io_wq_submit_work+0x6e9/0xb90 io_uring/io_uring.c:1874
io_worker_handle_work+0x7cd/0x1180 io_uring/io-wq.c:642
io_wq_worker+0x42f/0xeb0 io_uring/io-wq.c:696
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
which is supposed to be safe with how requests are allocated. But msg
ring requests alloc and free on their own, and hence must defer freeing
to a sane time.
Add an rcu_head and use kfree_rcu() in both spots where requests are
freed. Only the one in io_msg_tw_complete() is strictly required as it
has been visible on the other ring, but use it consistently in the other
spot as well.
This should not cause any other issues outside of KASAN rightfully
complaining about it.
Link: https://lore.kernel.org/io-uring/686cd2ea.a00a0220.338033.0007.GAE@google.com/
Reported-by: syzbot+54cbbfb4db9145d26fc2@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Fixes: 0617bb500b ("io_uring/msg_ring: improve handling of target CQE posting")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
(cherry picked from commit fc582cd26e)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 508c1314b3 upstream.
The io_futex_data is allocated upfront and assigned to the io_kiocb
async_data field, but the request isn't marked with REQ_F_ASYNC_DATA
at that point. Those two should always go together, as the flag tells
io_uring whether the field is valid or not.
Additionally, on failure cleanup, the futex handler frees the data but
does not clear ->async_data. Clear the data and the flag in the error
path as well.
Thanks to Trend Micro Zero Day Initiative and particularly ReDress for
reporting this.
Cc: stable@vger.kernel.org
Fixes: 194bb58c60 ("io_uring: add support for futex wake and wait")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 41b70df5b3 upstream.
Ring provided buffers are potentially only valid within the single
execution context in which they were acquired. io_uring deals with this
and invalidates them on retry. But on the networking side, if
MSG_WAITALL is set, or if the socket is of the streaming type and too
little was processed, then it will hang on to the buffer rather than
recycle or commit it. This is problematic for two reasons:
1) If someone unregisters the provided buffer ring before a later retry,
then the req->buf_list will no longer be valid.
2) If multiple sockers are using the same buffer group, then multiple
receives can consume the same memory. This can cause data corruption
in the application, as either receive could land in the same
userspace buffer.
Fix this by disallowing partial retries from pinning a provided buffer
across multiple executions, if ring provided buffers are used.
Cc: stable@vger.kernel.org
Reported-by: pt x <superman.xpt@gmail.com>
Fixes: c56e022c0a ("io_uring: add support for user mapped provided buffer ring")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 825aea662b upstream.
kernel test robot reports that a recent change of the sqe->rw_flags
field throws a sparse warning on 32-bit archs:
>> io_uring/rw.c:291:19: sparse: sparse: incorrect type in assignment (different base types) @@ expected restricted __kernel_rwf_t [usertype] flags @@ got unsigned int @@
io_uring/rw.c:291:19: sparse: expected restricted __kernel_rwf_t [usertype] flags
io_uring/rw.c:291:19: sparse: got unsigned int
Force cast it to rwf_t to silence that new sparse warning.
Fixes: cf73d9970e ("io_uring: don't use int for ABI")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202507032211.PwSNPNSP-lkp@intel.com/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c7cafd5b81 upstream.
8c8492ca64 ("io_uring/net: don't retry connect operation on EPOLLERR")
is a little dirty hack that
1) wrongfully assumes that POLLERR equals to a failed request, which
breaks all POLLERR users, e.g. all error queue recv interfaces.
2) deviates the connection request behaviour from connect(2), and
3) racy and solved at a wrong level.
Nothing can be done with 2) now, and 3) is beyond the scope of the
patch. At least solve 1) by moving the hack out of generic poll handling
into io_connect().
Cc: stable@vger.kernel.org
Fixes: 8c8492ca64 ("io_uring/net: don't retry connect operation on EPOLLERR")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/3dc89036388d602ebd84c28e5042e457bdfc952b.1752682444.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A previous commit aborted mapping more for a non-incremental ring for
bundle peeking, but depending on where in the process this peeking
happened, it would not necessarily prevent a retry by the user. That can
create gaps in the received/read data.
Add struct buf_sel_arg->partial_map, which can pass this information
back. The networking side can then map that to internal state and use it
to gate retry as well.
Since this necessitates a new flag, change io_sr_msg->retry to a
retry_flags member, and store both the retry and partial map condition
in there.
Cc: stable@vger.kernel.org
Fixes: 26ec15e4b0 ("io_uring/kbuf: don't truncate end buffer for multiple buffer peeks")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
(cherry picked from commit 178b8ff66f)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 9a709b7e98 upstream.
A bigger array of vecs could've been allocated, but
io_ring_buffers_peek() still decided to cap the mapped range depending
on how much data was available. Hence don't rely on the segment count
to know if the request should be marked as needing cleanup, always
check upfront if the iov array is different than the fast_iov array.
Fixes: 26ec15e4b0 ("io_uring/kbuf: don't truncate end buffer for multiple buffer peeks")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
A previous fix corrected the retry condition for when to continue a
current bundle, but it missed that the current (not the total) transfer
count also applies to the buffer put. If not, then for incrementally
consumed buffer rings repeated completions on the same request may end
up over consuming.
Reported-by: Roy Tang (ErgoniaTrading) <royonia@ergonia.io>
Cc: stable@vger.kernel.org
Fixes: 3a08988123 ("io_uring/net: only retry recv bundle for a full transfer")
Link: https://github.com/axboe/liburing/issues/1423
Signed-off-by: Jens Axboe <axboe@kernel.dk>
(cherry picked from commit 51a4598ad5)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 2c7f023219 upstream.
Currently retry and general validity of msg_inq is gated on it being
larger than zero, but it's entirely possible for this to be slightly
inaccurate. In particular, if FIN is received, it'll return 1.
Just use larger than 1 as the check. This covers both the FIN case, and
at the same time, it doesn't make much sense to retry a recv immediately
if there's even just a single 1 byte of valid data in the socket.
Leave the SOCK_NONEMPTY flagging when larger than 0 still, as an app may
use that for the final receive.
Cc: stable@vger.kernel.org
Reported-by: Christian Mazakas <christian.mazakas@gmail.com>
Fixes: 7c71a0af81 ("io_uring/net: improve recv bundles")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 3a08988123 upstream.
If a shorter than assumed transfer was seen, a partial buffer will have
been filled. For that case it isn't sane to attempt to fill more into
the bundle before posting a completion, as that will cause a gap in
the received data.
Check if the iterator has hit zero and only allow to continue a bundle
operation if that is the case.
Also ensure that for putting finished buffers, only the current transfer
is accounted. Otherwise too many buffers may be put for a short transfer.
Link: https://github.com/axboe/liburing/issues/1409
Cc: stable@vger.kernel.org
Fixes: 7c71a0af81 ("io_uring/net: improve recv bundles")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 7c71a0af81 upstream.
Current recv bundles are only supported for multishot receives, and
additionally they also always post at least 2 CQEs if more data is
available than what a buffer will hold. This happens because the initial
bundle recv will do a single buffer, and then do the rest of what is in
the socket as a followup receive. As shown in a test program, if 1k
buffers are available and 32k is available to receive in the socket,
you'd get the following completions:
bundle=1, mshot=0
cqe res 1024
cqe res 1024
[...]
cqe res 1024
bundle=1, mshot=1
cqe res 1024
cqe res 31744
where bundle=1 && mshot=0 will post 32 1k completions, and bundle=1 &&
mshot=1 will post a 1k completion and then a 31k completion.
To support bundle recv without multishot, it's possible to simply retry
the recv immediately and post a single completion, rather than split it
into two completions. With the below patch, the same test looks as
follows:
bundle=1, mshot=0
cqe res 32768
bundle=1, mshot=1
cqe res 32768
where mshot=0 works fine for bundles, and both of them post just a
single 32k completion rather than split it into separate completions.
Posting fewer completions is always a nice win, and not needing
multishot for proper bundle efficiency is nice for cases that can't
necessarily use multishot.
Reported-by: Norman Maurer <norman_maurer@apple.com>
Link: https://lore.kernel.org/r/184f9f92-a682-4205-a15d-89e18f664502@kernel.dk
Fixes: 2f9c9515bd ("io_uring/net: support bundles for recv")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit f2320f1dd6 ]
A recent commit moved the error handling of sqpoll thread and tctx
failures into the thread itself, as part of fixing an issue. However, it
missed that tctx allocation may also fail, and that
io_sq_offload_create() does its own error handling for the task_struct
in that case.
Remove the manual task putting in io_sq_offload_create(), as
io_sq_thread() will notice that the tctx did not get setup and hence it
should put itself and exit.
Reported-by: syzbot+763e12bbf004fb1062e4@syzkaller.appspotmail.com
Fixes: ac0b8b327a ("io_uring: fix use-after-free of sq->thread in __io_uring_show_fdinfo()")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 26ec15e4b0 upstream.
If peeking a bunch of buffers, normally io_ring_buffers_peek() will
truncate the end buffer. This isn't optimal as presumably more data will
be arriving later, and hence it's better to stop with the last full
buffer rather than truncate the end buffer.
Cc: stable@vger.kernel.org
Fixes: 35c8711c8f ("io_uring/kbuf: add helpers for getting/peeking multiple buffers")
Reported-by: Christian Mazakas <christian.mazakas@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit c538f400fa ]
The sqpoll thread is dereferenced with rcu read protection in one place,
so it needs to be annotated as an __rcu type, and should consistently
use rcu helpers for access and assignment to make sparse happy.
Since most of the accesses occur under the sqd->lock, we can use
rcu_dereference_protected() without declaring an rcu read section.
Provide a simple helper to get the thread from a locked context.
Fixes: ac0b8b327a ("io_uring: fix use-after-free of sq->thread in __io_uring_show_fdinfo()")
Signed-off-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20250611205343.1821117-1-kbusch@meta.com
[axboe: fold in fix for register.c]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
