gcc 11.4.1-3 warns about memcpy() with overlapping pointers:
drivers/net/wireless/ath/ath12k/wow.c: In function ‘ath12k_wow_convert_8023_to_80211.constprop’:
./include/linux/fortify-string.h:114:33: error: ‘__builtin_memcpy’ accessing 18446744073709551611 or more bytes at offsets 0 and 0 overlaps 9223372036854775799 bytes at offset -9223372036854775804 [-Werror=restrict]
114 | #define __underlying_memcpy __builtin_memcpy
| ^
./include/linux/fortify-string.h:637:9: note: in expansion of macro ‘__underlying_memcpy’
637 | __underlying_##op(p, q, __fortify_size); \
| ^~~~~~~~~~~~~
./include/linux/fortify-string.h:682:26: note: in expansion of macro ‘__fortify_memcpy_chk’
682 | #define memcpy(p, q, s) __fortify_memcpy_chk(p, q, s, \
| ^~~~~~~~~~~~~~~~~~~~
drivers/net/wireless/ath/ath12k/wow.c:190:25: note: in expansion of macro ‘memcpy’
190 | memcpy(pat, eth_pat, eth_pat_len);
| ^~~~~~
./include/linux/fortify-string.h:114:33: error: ‘__builtin_memcpy’ accessing 18446744073709551605 or more bytes at offsets 0 and 0 overlaps 9223372036854775787 bytes at offset -9223372036854775798 [-Werror=restrict]
114 | #define __underlying_memcpy __builtin_memcpy
| ^
./include/linux/fortify-string.h:637:9: note: in expansion of macro ‘__underlying_memcpy’
637 | __underlying_##op(p, q, __fortify_size); \
| ^~~~~~~~~~~~~
./include/linux/fortify-string.h:682:26: note: in expansion of macro ‘__fortify_memcpy_chk’
682 | #define memcpy(p, q, s) __fortify_memcpy_chk(p, q, s, \
| ^~~~~~~~~~~~~~~~~~~~
drivers/net/wireless/ath/ath12k/wow.c:232:25: note: in expansion of macro ‘memcpy’
232 | memcpy(pat, eth_pat, eth_pat_len);
| ^~~~~~
The sum of size_t operands can overflow SIZE_MAX, triggering the
warning.
Address the issue using the suitable helper.
Fixes: 4a3c212eee ("wifi: ath12k: add basic WoW functionalities")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Link: https://patch.msgid.link/3175f87d7227e395b330fd88fb840c1645084ea7.1721127979.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
b49991d83b