On 7/16/2024 7:00 AM, Jeff Johnson wrote:
> On 7/16/2024 4:06 AM, Paolo Abeni wrote:
>> 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: 4a3c212eee0e ("wifi: ath12k: add basic WoW functionalities")
>> Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
>> ---
>> Only built tested. Sending directly to net to reduce the RTT, but no
>> objections to go through the WiFi tree first
>> ---
>> drivers/net/wireless/ath/ath12k/wow.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/net/wireless/ath/ath12k/wow.c b/drivers/net/wireless/ath/ath12k/wow.c
>> index c5cba825a84a..bead19db2c9a 100644
>> --- a/drivers/net/wireless/ath/ath12k/wow.c
>> +++ b/drivers/net/wireless/ath/ath12k/wow.c
>> @@ -186,7 +186,7 @@ ath12k_wow_convert_8023_to_80211(struct ath12k *ar,
>> if (eth_pkt_ofs < ETH_ALEN) {
>> pkt_ofs = eth_pkt_ofs + a1_ofs;
>>
>> - if (eth_pkt_ofs + eth_pat_len < ETH_ALEN) {
>> + if (size_add(eth_pkt_ofs, eth_pat_len) < ETH_ALEN) {
>> memcpy(pat, eth_pat, eth_pat_len);
>> memcpy(bytemask, eth_bytemask, eth_pat_len);
>>
>> @@ -228,7 +228,7 @@ ath12k_wow_convert_8023_to_80211(struct ath12k *ar,
>> } else if (eth_pkt_ofs < prot_ofs) {
>> pkt_ofs = eth_pkt_ofs - ETH_ALEN + a3_ofs;
>>
>> - if (eth_pkt_ofs + eth_pat_len < prot_ofs) {
>> + if (size_add(eth_pkt_ofs, eth_pat_len) < prot_ofs) {
>> memcpy(pat, eth_pat, eth_pat_len);
>> memcpy(bytemask, eth_bytemask, eth_pat_len);
>>
>
> Duplicate of https://msgid.link/20240704144341.207317-1-kvalo@xxxxxxxxxx ??
Let me add Kees & Paul to see if they prefer your solution
