| Message ID | 20230728231245.never.309-kees@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | wifi: ray_cs: Replace 1-element array with flexible array | expand |
Kees Cook <keescook@chromium.org> wrote: > The trailing array member of struct tx_buf was defined as a 1-element > array, but used as a flexible array. This was resulting in build warnings: > > In function 'fortify_memset_chk', > inlined from 'memset_io' at /kisskb/src/arch/mips/include/asm/io.h:486:2, > inlined from 'build_auth_frame' at /kisskb/src/drivers/net/wireless/legacy/ray_cs.c:2697:2: > /kisskb/src/include/linux/fortify-string.h:493:25: error: call to '__write_overflow_field' declared with attribute warning: > detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning] > 493 | __write_overflow_field(p_size_field, size); > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > Replace it with an actual flexible array. Binary difference comparison > shows a single change in output: > > │ drivers/net/wireless/legacy/ray_cs.c:883 > │ lea 0x1c(%rbp),%r13d > │ - cmp $0x7c3,%r13d > │ + cmp $0x7c4,%r13d > > This is from: > > if (len + TX_HEADER_LENGTH > TX_BUF_SIZE) { > > specifically: > > #define TX_BUF_SIZE (2048 - sizeof(struct tx_msg)) > > This appears to have been originally buggy, so the change is correct. > > Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> > Closes: https://lore.kernel.org/all/88f83d73-781d-bdc-126-aa629cb368c@linux-m68k.org > Cc: Kalle Valo <kvalo@kernel.org> > Cc: linux-wireless@vger.kernel.org > Signed-off-by: Kees Cook <keescook@chromium.org> Patch applied to wireless.git, thanks. 1d7dd5aa3547 wifi: ray_cs: Replace 1-element array with flexible array
diff --git a/drivers/net/wireless/legacy/rayctl.h b/drivers/net/wireless/legacy/rayctl.h index 2b0f332043d7..1f3bde8ac73d 100644 --- a/drivers/net/wireless/legacy/rayctl.h +++ b/drivers/net/wireless/legacy/rayctl.h @@ -577,7 +577,7 @@ struct tx_msg { struct tib_structure tib; struct phy_header phy; struct mac_header mac; - UCHAR var[1]; + UCHAR var[]; }; /****** ECF Receive Control Structure (RCS) Area at Shared RAM offset 0x0800 */
The trailing array member of struct tx_buf was defined as a 1-element array, but used as a flexible array. This was resulting in build warnings: In function 'fortify_memset_chk', inlined from 'memset_io' at /kisskb/src/arch/mips/include/asm/io.h:486:2, inlined from 'build_auth_frame' at /kisskb/src/drivers/net/wireless/legacy/ray_cs.c:2697:2: /kisskb/src/include/linux/fortify-string.h:493:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning] 493 | __write_overflow_field(p_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Replace it with an actual flexible array. Binary difference comparison shows a single change in output: │ drivers/net/wireless/legacy/ray_cs.c:883 │ lea 0x1c(%rbp),%r13d │ - cmp $0x7c3,%r13d │ + cmp $0x7c4,%r13d This is from: if (len + TX_HEADER_LENGTH > TX_BUF_SIZE) { specifically: #define TX_BUF_SIZE (2048 - sizeof(struct tx_msg)) This appears to have been originally buggy, so the change is correct. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Closes: https://lore.kernel.org/all/88f83d73-781d-bdc-126-aa629cb368c@linux-m68k.org Cc: Kalle Valo <kvalo@kernel.org> Cc: linux-wireless@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> --- drivers/net/wireless/legacy/rayctl.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)