mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-09-22 09:34:56 +02:00
Gustavo A. R. Silva
235fd607c6
One-element arrays are deprecated, and we are replacing them with flexible
array members instead. So, replace one-element array with flexible-array
member in struct mwifiex_ie_types_rates_param_set.
These are the only binary differences I see after the change:
mwifiex.o
_@@ -50154,7 +50154,7 @@
23514: R_X86_64_32S kmalloc_caches+0x50
23518: call 2351d <mwifiex_scan_networks+0x11d>
23519: R_X86_64_PLT32 __tsan_read8-0x4
- 2351d: mov $0x225,%edx
+ 2351d: mov $0x224,%edx
23522: mov $0xdc0,%esi
23527: mov 0x0(%rip),%rdi # 2352e <mwifiex_scan_networks+0x12e>
2352a: R_X86_64_PC32 kmalloc_caches+0x4c
scan.o
_@@ -5582,7 +5582,7 @@
4394: R_X86_64_32S kmalloc_caches+0x50
4398: call 439d <mwifiex_scan_networks+0x11d>
4399: R_X86_64_PLT32 __tsan_read8-0x4
- 439d: mov $0x225,%edx
+ 439d: mov $0x224,%edx
43a2: mov $0xdc0,%esi
43a7: mov 0x0(%rip),%rdi # 43ae <mwifiex_scan_networks+0x12e>
43aa: R_X86_64_PC32 kmalloc_caches+0x4c
and the reason for that is the following line:
drivers/net/wireless/marvell/mwifiex/scan.c:
1517 scan_cfg_out = kzalloc(sizeof(union mwifiex_scan_cmd_config_tlv),
1518 GFP_KERNEL);
sizeof(union mwifiex_scan_cmd_config_tlv) is now one-byte smaller due to the
flex-array transformation:
46 union mwifiex_scan_cmd_config_tlv {
47 /* Scan configuration (variable length) */
48 struct mwifiex_scan_cmd_config config;
49 /* Max allocated block */
50 u8 config_alloc_buf[MAX_SCAN_CFG_ALLOC];
51 };
Notice that MAX_SCAN_CFG_ALLOC is defined in terms of
sizeof(struct mwifiex_ie_types_rates_param_set), see:
26 /* Memory needed to store supported rate */
27 #define RATE_TLV_MAX_SIZE (sizeof(struct mwifiex_ie_types_rates_param_set) \
28 + HOSTCMD_SUPPORTED_RATES)
37 /* Maximum memory needed for a mwifiex_scan_cmd_config with all TLVs at max */
38 #define MAX_SCAN_CFG_ALLOC (sizeof(struct mwifiex_scan_cmd_config) \
39 + sizeof(struct mwifiex_ie_types_num_probes) \
40 + sizeof(struct mwifiex_ie_types_htcap) \
41 + CHAN_TLV_MAX_SIZE \
42 + RATE_TLV_MAX_SIZE \
43 + WILDCARD_SSID_TLV_MAX_SIZE)
This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
routines on memcpy() and help us make progress towards globally
enabling -fstrict-flex-arrays=3 [1].
Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/252
Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html [1]
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/Y9xkjXeElSEQ0FPY@work
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.