lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20230908181555.3459640-8-sashal@kernel.org>
Date:   Fri,  8 Sep 2023 14:15:22 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Dmitry Antipov <dmantipov@...dex.ru>,
        Brian Norris <briannorris@...omium.org>,
        Kalle Valo <kvalo@...nel.org>, Sasha Levin <sashal@...nel.org>,
        linux-wireless@...r.kernel.org
Subject: [PATCH AUTOSEL 6.4 08/41] wifi: mwifiex: fix fortify warning

From: Dmitry Antipov <dmantipov@...dex.ru>

[ 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@...omium.org>
Signed-off-by: Dmitry Antipov <dmantipov@...dex.ru>
Reviewed-by: Brian Norris <briannorris@...omium.org>
Signed-off-by: Kalle Valo <kvalo@...nel.org>
Link: https://lore.kernel.org/r/20230629085115.180499-2-dmantipov@yandex.ru
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/net/wireless/marvell/mwifiex/tdls.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/marvell/mwifiex/tdls.c b/drivers/net/wireless/marvell/mwifiex/tdls.c
index 97bb87c3676bb..6c60621b6cccb 100644
--- a/drivers/net/wireless/marvell/mwifiex/tdls.c
+++ b/drivers/net/wireless/marvell/mwifiex/tdls.c
@@ -735,6 +735,7 @@ 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;
@@ -753,7 +754,10 @@ 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;
@@ -762,8 +766,7 @@ 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 */
 		eth_broadcast_addr(pos);
 
-- 
2.40.1

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ