From: Ben Hutchings <ben@decadent•org.uk>
To: Jon Maloy <jon.maloy@ericsson•com>, Ying Xue <ying.xue@windriver•com>
Cc: netdev@vger•kernel.org, Qian Zhang <zhangqian-c@360•cn>,
Eric Dumazet <edumazet@google•com>
Subject: [PATCH net] tipc: Guard against tiny MTU in tipc_msg_build()
Date: Wed, 19 Oct 2016 03:16:54 +0100 [thread overview]
Message-ID: <20161019021654.GD2773@decadent.org.uk> (raw)
[-- Attachment #1: Type: text/plain, Size: 1097 bytes --]
Qian Zhang (张谦) reported a potential socket buffer overflow in
tipc_msg_build(). The minimum fragment length needs to be checked
against the maximum packet size, which is based on the link MTU.
Reported-by: Qian Zhang (张谦) <zhangqian-c@360•cn>
Signed-off-by: Ben Hutchings <ben@decadent•org.uk>
---
This is untested, but I think it fixes the issue reported. Ideally
tipc_l2_device_event() would also disable use of TIPC on devices with
too small an MTU, like several other protocols do.
Ben.
net/tipc/msg.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/net/tipc/msg.c b/net/tipc/msg.c
index 17201aa8423d..b9124ac82c29 100644
--- a/net/tipc/msg.c
+++ b/net/tipc/msg.c
@@ -274,6 +274,10 @@ int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m,
goto error;
}
+ /* Check that fragment and message header will fit */
+ if (INT_H_SIZE + mhsz > pktmax)
+ return -EMSGSIZE;
+
/* Prepare reusable fragment header */
tipc_msg_init(msg_prevnode(mhdr), &pkthdr, MSG_FRAGMENTER,
FIRST_FRAGMENT, INT_H_SIZE, msg_destnode(mhdr));
[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 811 bytes --]
next reply other threads:[~2016-10-19 2:17 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-19 2:16 Ben Hutchings [this message]
2016-10-20 9:30 ` [PATCH net] tipc: Guard against tiny MTU in tipc_msg_build() Ying Xue
2016-10-20 12:46 ` Ben Hutchings
2016-10-20 14:51 ` Jon Maloy
2016-10-20 16:40 ` Ben Hutchings
2016-10-21 14:57 ` Jon Maloy
2016-10-21 15:00 ` Ben Hutchings
-- strict thread matches above, loose matches on Subject: below --
2016-11-01 6:35 张谦
2016-11-01 11:36 ` Jon Maloy
2016-11-04 7:23 张谦
2016-11-04 15:57 ` Jon Maloy
2016-11-04 17:45 ` 张谦
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20161019021654.GD2773@decadent.org.uk \
--to=ben@decadent$(echo .)org.uk \
--cc=edumazet@google$(echo .)com \
--cc=jon.maloy@ericsson$(echo .)com \
--cc=netdev@vger$(echo .)kernel.org \
--cc=ying.xue@windriver$(echo .)com \
--cc=zhangqian-c@360$(echo .)cn \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox