This is a note to let you know that I've just added the patch titled
wifi: mwifiex: fix fortify warning
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
wifi-mwifiex-fix-fortify-warning.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit c83e0d914aff1da14b2ef59306e0ea96b7215ffc
Author: Dmitry Antipov <dmantipov@xxxxxxxxx>
Date: Thu Jun 29 11:51:01 2023 +0300
wifi: mwifiex: fix fortify warning
[ Upstream commit dcce94b80a954a8968ff29fafcfb066d6197fa9a ]
When compiling with gcc 13.1 and CONFIG_FORTIFY_SOURCE=y,
I've noticed the following:
In function ‘fortify_memcpy_chk’,
inlined from ‘mwifiex_construct_tdls_action_frame’ at drivers/net/wireless/marvell/mwifiex/tdls.c:765:3,
inlined from ‘mwifiex_send_tdls_action_frame’ at drivers/net/wireless/marvell/mwifiex/tdls.c:856:6:
./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);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The compiler actually complains on:
memmove(pos + ETH_ALEN, &mgmt->u.action.category,
sizeof(mgmt->u.action.u.tdls_discover_resp));
and it happens because the fortification logic interprets this
as an attempt to overread 1-byte 'u.action.category' member of
'struct ieee80211_mgmt'. To silence this warning, it's enough
to pass an address of 'u.action' itself instead of an address
of its first member.
This also fixes an improper usage of 'sizeof()'. Since 'skb' is
extended with 'sizeof(mgmt->u.action.u.tdls_discover_resp) + 1'
bytes (where 1 is actually 'sizeof(mgmt->u.action.category)'),
I assume that the same number of bytes should be copied.
Suggested-by: Brian Norris <briannorris@xxxxxxxxxxxx>
Signed-off-by: Dmitry Antipov <dmantipov@xxxxxxxxx>
Reviewed-by: Brian Norris <briannorris@xxxxxxxxxxxx>
Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230629085115.180499-2-dmantipov@xxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/wireless/marvell/mwifiex/tdls.c b/drivers/net/wireless/marvell/mwifiex/tdls.c
index b6b7bbe168ebc..12cfc95f02598 100644
--- a/drivers/net/wireless/marvell/mwifiex/tdls.c
+++ b/drivers/net/wireless/marvell/mwifiex/tdls.c
@@ -737,6 +737,7 @@ mwifiex_construct_tdls_action_frame(struct mwifiex_private *priv,
int ret;
u16 capab;
struct ieee80211_ht_cap *ht_cap;
+ unsigned int extra;
u8 radio, *pos;
capab = priv->curr_bss_params.bss_descriptor.cap_info_bitmap;
@@ -755,7 +756,10 @@ mwifiex_construct_tdls_action_frame(struct mwifiex_private *priv,
switch (action_code) {
case WLAN_PUB_ACTION_TDLS_DISCOVER_RES:
- skb_put(skb, sizeof(mgmt->u.action.u.tdls_discover_resp) + 1);
+ /* See the layout of 'struct ieee80211_mgmt'. */
+ extra = sizeof(mgmt->u.action.u.tdls_discover_resp) +
+ sizeof(mgmt->u.action.category);
+ skb_put(skb, extra);
mgmt->u.action.category = WLAN_CATEGORY_PUBLIC;
mgmt->u.action.u.tdls_discover_resp.action_code =
WLAN_PUB_ACTION_TDLS_DISCOVER_RES;
@@ -764,8 +768,7 @@ mwifiex_construct_tdls_action_frame(struct mwifiex_private *priv,
mgmt->u.action.u.tdls_discover_resp.capability =
cpu_to_le16(capab);
/* move back for addr4 */
- memmove(pos + ETH_ALEN, &mgmt->u.action.category,
- sizeof(mgmt->u.action.u.tdls_discover_resp));
+ memmove(pos + ETH_ALEN, &mgmt->u.action, extra);
/* init address 4 */
memcpy(pos, bc_addr, ETH_ALEN);
