| Message ID | 20230620080855.396851-2-dmantipov@yandex.ru (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 810e41cebb6c6e394f2068f839e1a3fc745a5dcc |
| Delegated to: | Kalle Valo |
| Headers | show |
| Series | [1/2,v2] wifi: ath9k: avoid using uninitialized array | expand |
Dmitry Antipov <dmantipov@yandex.ru> writes: > When compiling with gcc 13.1 and CONFIG_FORTIFY_SOURCE=y, > I've noticed the following: > > In function ‘fortify_memcpy_chk’, > inlined from ‘ath_tx_complete_aggr’ at drivers/net/wireless/ath/ath9k/xmit.c:556:4, > inlined from ‘ath_tx_process_buffer’ at drivers/net/wireless/ath/ath9k/xmit.c:773:3: > ./include/linux/fortify-string.h:529:25: warning: call to ‘__read_overflow2_field’ > declared with attribute warning: detected read beyond size of field (2nd parameter); > maybe use struct_group()? [-Wattribute-warning] > 529 | __read_overflow2_field(q_size_field, size); > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > In function ‘fortify_memcpy_chk’, > inlined from ‘ath_tx_count_frames’ at drivers/net/wireless/ath/ath9k/xmit.c:473:3, > inlined from ‘ath_tx_complete_aggr’ at drivers/net/wireless/ath/ath9k/xmit.c:572:2, > inlined from ‘ath_tx_process_buffer’ at drivers/net/wireless/ath/ath9k/xmit.c:773:3: > ./include/linux/fortify-string.h:529:25: warning: call to ‘__read_overflow2_field’ > declared with attribute warning: detected read beyond size of field (2nd parameter); > maybe use struct_group()? [-Wattribute-warning] > 529 | __read_overflow2_field(q_size_field, size); > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > In both cases, the compiler complains on: > > memcpy(ba, &ts->ba_low, WME_BA_BMP_SIZE >> 3); > > which is the legal way to copy both 'ba_low' and following 'ba_high' > members of 'struct ath_tx_status' at once (that is, issue one 8-byte > 'memcpy()' for two 4-byte fields). Since the fortification logic seems > interprets this trick as an attempt to overread 4-byte 'ba_low', silence > relevant warnings by using the convenient 'struct_group()' quirk. > > Suggested-by: Johannes Berg <johannes@sipsolutions.net> > Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru> Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
diff --git a/drivers/net/wireless/ath/ath9k/mac.h b/drivers/net/wireless/ath/ath9k/mac.h index af44b33814dd..f03d792732da 100644 --- a/drivers/net/wireless/ath/ath9k/mac.h +++ b/drivers/net/wireless/ath/ath9k/mac.h @@ -115,8 +115,10 @@ struct ath_tx_status { u8 qid; u16 desc_id; u8 tid; - u32 ba_low; - u32 ba_high; + struct_group(ba, + u32 ba_low; + u32 ba_high; + ); u32 evm0; u32 evm1; u32 evm2; diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c index 8babaaacacf5..4e939dcac1c9 100644 --- a/drivers/net/wireless/ath/ath9k/xmit.c +++ b/drivers/net/wireless/ath/ath9k/xmit.c @@ -470,7 +470,7 @@ static void ath_tx_count_frames(struct ath_softc *sc, struct ath_buf *bf, if (isaggr) { seq_st = ts->ts_seqnum; - memcpy(ba, &ts->ba_low, WME_BA_BMP_SIZE >> 3); + memcpy(ba, &ts->ba, WME_BA_BMP_SIZE >> 3); } while (bf) { @@ -553,7 +553,7 @@ static void ath_tx_complete_aggr(struct ath_softc *sc, struct ath_txq *txq, if (isaggr && txok) { if (ts->ts_flags & ATH9K_TX_BA) { seq_st = ts->ts_seqnum; - memcpy(ba, &ts->ba_low, WME_BA_BMP_SIZE >> 3); + memcpy(ba, &ts->ba, WME_BA_BMP_SIZE >> 3); } else { /* * AR5416 can become deaf/mute when BA
When compiling with gcc 13.1 and CONFIG_FORTIFY_SOURCE=y, I've noticed the following: In function ‘fortify_memcpy_chk’, inlined from ‘ath_tx_complete_aggr’ at drivers/net/wireless/ath/ath9k/xmit.c:556:4, inlined from ‘ath_tx_process_buffer’ at drivers/net/wireless/ath/ath9k/xmit.c:773:3: ./include/linux/fortify-string.h:529:25: warning: call to ‘__read_overflow2_field’ declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Wattribute-warning] 529 | __read_overflow2_field(q_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In function ‘fortify_memcpy_chk’, inlined from ‘ath_tx_count_frames’ at drivers/net/wireless/ath/ath9k/xmit.c:473:3, inlined from ‘ath_tx_complete_aggr’ at drivers/net/wireless/ath/ath9k/xmit.c:572:2, inlined from ‘ath_tx_process_buffer’ at drivers/net/wireless/ath/ath9k/xmit.c:773:3: ./include/linux/fortify-string.h:529:25: warning: call to ‘__read_overflow2_field’ declared with attribute warning: detected read beyond size of field (2nd parameter); maybe use struct_group()? [-Wattribute-warning] 529 | __read_overflow2_field(q_size_field, size); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In both cases, the compiler complains on: memcpy(ba, &ts->ba_low, WME_BA_BMP_SIZE >> 3); which is the legal way to copy both 'ba_low' and following 'ba_high' members of 'struct ath_tx_status' at once (that is, issue one 8-byte 'memcpy()' for two 4-byte fields). Since the fortification logic seems interprets this trick as an attempt to overread 4-byte 'ba_low', silence relevant warnings by using the convenient 'struct_group()' quirk. Suggested-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru> --- v2: prefer struct_group() over offsetof() (Johannes Berg) --- drivers/net/wireless/ath/ath9k/mac.h | 6 ++++-- drivers/net/wireless/ath/ath9k/xmit.c | 4 ++-- 2 files changed, 6 insertions(+), 4 deletions(-)