Messages in this thread Patch in this message | | | From | Kees Cook <> | Subject | [PATCH] staging: r8188eu: Check for NULL header value | Date | Wed, 12 Jan 2022 16:19:34 -0800 |
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When building with -Warray-bounds, the following warning is emitted:
In file included from ./include/linux/string.h:253, from ./arch/x86/include/asm/page_32.h:22, from ./arch/x86/include/asm/page.h:14, from ./arch/x86/include/asm/thread_info.h:12, from ./include/linux/thread_info.h:60, from ./arch/x86/include/asm/preempt.h:7, from ./include/linux/preempt.h:78, from ./include/linux/rcupdate.h:27, from ./include/linux/rculist.h:11, from ./include/linux/sched/signal.h:5, from ./drivers/staging/rtl8723bs/include/drv_types.h:17, from drivers/staging/rtl8723bs/core/rtw_recv.c:7: In function 'memcpy', inlined from 'wlanhdr_to_ethhdr' at drivers/staging/rtl8723bs/core/rtw_recv.c:1554:2: ./include/linux/fortify-string.h:41:33: warning: '__builtin_memcpy' offset [0, 5] is out of the bounds [0, 0] [-Warray-bounds] 41 | #define __underlying_memcpy __builtin_memcpy | ^
This is because the compiler sees it is possible for "ptr" to be a NULL value, and concludes that it has zero size and attempts to copy to it would overflow. Instead, detect the NULL return and error out early.
Cc: Larry Finger <Larry.Finger@lwfinger.net> Cc: Phillip Potter <phil@philpotter.co.uk> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Michael Straube <straube.linux@gmail.com> Cc: Fabio Aiuto <fabioaiuto83@gmail.com> Cc: linux-staging@lists.linux.dev Signed-off-by: Kees Cook <keescook@chromium.org> --- drivers/staging/r8188eu/core/rtw_recv.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/staging/r8188eu/core/rtw_recv.c b/drivers/staging/r8188eu/core/rtw_recv.c index 51a13262a226..93b0aa5688e3 100644 --- a/drivers/staging/r8188eu/core/rtw_recv.c +++ b/drivers/staging/r8188eu/core/rtw_recv.c @@ -1191,6 +1191,9 @@ static int wlanhdr_to_ethhdr(struct recv_frame *precvframe) u8 *ptr = get_recvframe_data(precvframe); /* point to frame_ctrl field */ struct rx_pkt_attrib *pattrib = &precvframe->attrib; + if (!ptr) + return _FAIL; + if (pattrib->encrypt) recvframe_pull_tail(precvframe, pattrib->icv_len); -- 2.30.2
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