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 for Android: free password hash cracker in your pocket
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-ID: <1415255192-13584-1-git-send-email-suhyun.park@ahnlab.com>
Date:	Thu, 6 Nov 2014 15:26:32 +0900
From:	Su-Hyun Park <suhyun.park@...lab.com>
To:	Stephen Hemminger <stephen@...workplumber.org>,
	"David S. Miller" <davem@...emloft.net>
CC:	<bridge@...ts.linux-foundation.org>, <netdev@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>,
	Su-Hyun Park <suhyun.park@...lab.com>
Subject: [PATCH] bridge: missing null bridge device check causing null pointer dereference (bugfix)

the bridge device can be null if the bridge is being deleted while processing 
the packet, which causes the null pointer dereference in switch statement.

crash dump snippet:

<1>BUG: unable to handle kernel NULL pointer dereference at 0000000000000021
<1>IP: [<ffffffff814179f6>] br_handle_frame+0xe6/0x270

<0>Code: 4c 0f 44 f0 89 f8 66 33 15 32 52 24 00 66 33 05 29 52 24 00 09 c2 89 
f0 66 33 05 22 52 24 00 80 e4 f0 66 09 c2 0f 84 eb 00 00 00 <41> 0f b6 46 21 
3c 02 74 61 3c 03 74 1d 48 89 df e8 d5 bc f0 ff
---
 net/bridge/br_input.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/bridge/br_input.c b/net/bridge/br_input.c
index 6fd5522..7e899ca 100644
--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -176,6 +176,8 @@ rx_handler_result_t br_handle_frame(struct sk_buff **pskb)
 		return RX_HANDLER_CONSUMED;
 
 	p = br_port_get_rcu(skb->dev);
+	if (!p)
+		goto drop;
 
 	if (unlikely(is_link_local_ether_addr(dest))) {
 		u16 fwd_mask = p->br->group_fwd_mask_required;
-- 
1.8.1.4

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Powered by blists - more mailing lists