This is a note to let you know that I've just added the patch titled
sctp: make sure stream nums can match optlen in sctp_setsockopt_reset_streams
to the 4.14-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:
sctp-make-sure-stream-nums-can-match-optlen-in-sctp_setsockopt_reset_streams.patch
and it can be found in the queue-4.14 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 Sun Dec 31 11:12:48 CET 2017
From: Xin Long <lucien.xin@xxxxxxxxx>
Date: Sun, 10 Dec 2017 15:40:51 +0800
Subject: sctp: make sure stream nums can match optlen in sctp_setsockopt_reset_streams
From: Xin Long <lucien.xin@xxxxxxxxx>
[ Upstream commit 2342b8d95bcae5946e1b9b8d58645f37500ef2e7 ]
Now in sctp_setsockopt_reset_streams, it only does the check
optlen < sizeof(*params) for optlen. But it's not enough, as
params->srs_number_streams should also match optlen.
If the streams in params->srs_stream_list are less than stream
nums in params->srs_number_streams, later when dereferencing
the stream list, it could cause a slab-out-of-bounds crash, as
reported by syzbot.
This patch is to fix it by also checking the stream numbers in
sctp_setsockopt_reset_streams to make sure at least it's not
greater than the streams in the list.
Fixes: 7f9d68ac944e ("sctp: implement sender-side procedures for SSN Reset Request Parameter")
Reported-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
Acked-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/sctp/socket.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -3874,13 +3874,17 @@ static int sctp_setsockopt_reset_streams
struct sctp_association *asoc;
int retval = -EINVAL;
- if (optlen < sizeof(struct sctp_reset_streams))
+ if (optlen < sizeof(*params))
return -EINVAL;
params = memdup_user(optval, optlen);
if (IS_ERR(params))
return PTR_ERR(params);
+ if (params->srs_number_streams * sizeof(__u16) >
+ optlen - sizeof(*params))
+ goto out;
+
asoc = sctp_id2assoc(sk, params->srs_assoc_id);
if (!asoc)
goto out;
Patches currently in stable-queue which might be from lucien.xin@xxxxxxxxx are
queue-4.14/sctp-make-sure-stream-nums-can-match-optlen-in-sctp_setsockopt_reset_streams.patch
queue-4.14/ipv6-mcast-better-catch-silly-mtu-values.patch