[PATCH AUTOSEL 6.4 10/41] wifi: wil6210: fix fortify warnings

Sasha Levin
2023-09-08T18:19:29Z

From: Dmitry Antipov <dmantipov@yandex.ru>

[ Upstream commit 1ad8237e971630c66a1a6194491e0837b64d00e0 ]

When compiling with gcc 13.1 and CONFIG_FORTIFY_SOURCE=y,
I've noticed the following:

In function ‘fortify_memcpy_chk’,
inlined from ‘wil_rx_crypto_check_edma’ at drivers/net/wireless/ath/wil6210/txrx_edma.c:566:2:
./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);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

where the compiler complains on:

const u8 *pn;
...
pn = (u8 *)&st->ext.pn_15_0;
...
memcpy(cc->pn, pn, IEEE80211_GCMP_PN_LEN);

and:

In function ‘fortify_memcpy_chk’,
inlined from ‘wil_rx_crypto_check’ at drivers/net/wireless/ath/wil6210/txrx.c:684:2:
./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);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

where the compiler complains on:

const u8 *pn = (u8 *)&d->mac.pn_15_0;
...
memcpy(cc->pn, pn, IEEE80211_GCMP_PN_LEN);

In both cases, the fortification logic interprets 'memcpy()' as 6-byte
overread of 2-byte field 'pn_15_0' of 'struct wil_rx_status_extension'
and 'pn_15_0' of 'struct vring_rx_mac', respectively. To silence
these warnings, last two fields of the aforementioned structures
are grouped using 'struct_group_attr(pn, __packed' quirk.

Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230621093711.80118-1-dmantipov@yandex.ru
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/ath/wil6210/txrx.c | 2 +-
drivers/net/wireless/ath/wil6210/txrx.h | 6 ++++--
drivers/net/wireless/ath/wil6210/txrx_edma.c | 2 +-
drivers/net/wireless/ath/wil6210/txrx_edma.h | 6 ++++--
4 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/ath/wil6210/txrx.c b/drivers/net/wireless/ath/wil6210/txrx.c
index 237cbd5c5060b..f29ac6de71399 100644
--- a/drivers/net/wireless/ath/wil6210/txrx.c
+++ b/drivers/net/wireless/ath/wil6210/txrx.c
@@ -666,7 +666,7 @@ static int wil_rx_crypto_check(struct wil6210_priv *wil, struct sk_buff *skb)
struct wil_tid_crypto_rx *c = mc ? &s->group_crypto_rx :
&s->tid_crypto_rx[tid];
struct wil_tid_crypto_rx_single *cc = &c->key_id[key_id];
- const u8 *pn = (u8 *)&d->mac.pn_15_0;
+ const u8 *pn = (u8 *)&d->mac.pn;

if (!cc->key_set) {
wil_err_ratelimited(wil,
diff --git a/drivers/net/wireless/ath/wil6210/txrx.h b/drivers/net/wireless/ath/wil6210/txrx.h
index 1ae1bec1b97f1..689f68d89a440 100644
--- a/drivers/net/wireless/ath/wil6210/txrx.h
+++ b/drivers/net/wireless/ath/wil6210/txrx.h
@@ -343,8 +343,10 @@ struct vring_rx_mac {
u32 d0;
u32 d1;
u16 w4;
- u16 pn_15_0;
- u32 pn_47_16;
+ struct_group_attr(pn, __packed,
+ u16 pn_15_0;
+ u32 pn_47_16;
+ );
} __packed;

/* Rx descriptor - DMA part
diff --git a/drivers/net/wireless/ath/wil6210/txrx_edma.c b/drivers/net/wireless/ath/wil6210/txrx_edma.c
index 201c8c35e0c9e..1ba1f21ebea26 100644
--- a/drivers/net/wireless/ath/wil6210/txrx_edma.c
+++ b/drivers/net/wireless/ath/wil6210/txrx_edma.c
@@ -548,7 +548,7 @@ static int wil_rx_crypto_check_edma(struct wil6210_priv *wil,
s = &wil->sta[cid];
c = mc ? &s->group_crypto_rx : &s->tid_crypto_rx[tid];
cc = &c->key_id[key_id];
- pn = (u8 *)&st->ext.pn_15_0;
+ pn = (u8 *)&st->ext.pn;

if (!cc->key_set) {
wil_err_ratelimited(wil,
diff --git a/drivers/net/wireless/ath/wil6210/txrx_edma.h b/drivers/net/wireless/ath/wil6210/txrx_edma.h
index c736f7413a35f..ee90e225bb050 100644
--- a/drivers/net/wireless/ath/wil6210/txrx_edma.h
+++ b/drivers/net/wireless/ath/wil6210/txrx_edma.h
@@ -330,8 +330,10 @@ struct wil_rx_status_extension {
u32 d0;
u32 d1;
__le16 seq_num; /* only lower 12 bits */
- u16 pn_15_0;
- u32 pn_47_16;
+ struct_group_attr(pn, __packed,
+ u16 pn_15_0;
+ u32 pn_47_16;
+ );
} __packed;

struct wil_rx_status_extended {
--
2.40.1