This is a note to let you know that I've just added the patch titled
net_sched: fix datalen for ematch
to the 4.9-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:
net_sched-fix-datalen-for-ematch.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Mon 27 Jan 2020 04:06:27 PM CET
From: Cong Wang <xiyou.wangcong@xxxxxxxxx>
Date: Wed, 22 Jan 2020 15:42:02 -0800
Subject: net_sched: fix datalen for ematch
From: Cong Wang <xiyou.wangcong@xxxxxxxxx>
[ Upstream commit 61678d28d4a45ef376f5d02a839cc37509ae9281 ]
syzbot reported an out-of-bound access in em_nbyte. As initially
analyzed by Eric, this is because em_nbyte sets its own em->datalen
in em_nbyte_change() other than the one specified by user, but this
value gets overwritten later by its caller tcf_em_validate().
We should leave em->datalen untouched to respect their choices.
I audit all the in-tree ematch users, all of those implement
->change() set em->datalen, so we can just avoid setting it twice
in this case.
Reported-and-tested-by: syzbot+5af9a90dad568aa9f611@xxxxxxxxxxxxxxxxxxxxxxxxx
Reported-by: syzbot+2f07903a5b05e7f36410@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Signed-off-by: Cong Wang <xiyou.wangcong@xxxxxxxxx>
Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/sched/ematch.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/sched/ematch.c
+++ b/net/sched/ematch.c
@@ -267,12 +267,12 @@ static int tcf_em_validate(struct tcf_pr
}
em->data = (unsigned long) v;
}
+ em->datalen = data_len;
}
}
em->matchid = em_hdr->matchid;
em->flags = em_hdr->flags;
- em->datalen = data_len;
em->net = net;
err = 0;
Patches currently in stable-queue which might be from xiyou.wangcong@xxxxxxxxx are
queue-4.9/net_sched-fix-datalen-for-ematch.patch
queue-4.9/net-netem-fix-backlog-accounting-for-corrupted-gso-f.patch
