This is a note to let you know that I've just added the patch titled sctp: avoid BUG_ON on sctp_wait_for_sndbuf 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: sctp-avoid-bug_on-on-sctp_wait_for_sndbuf.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 Tue Feb 14 17:03:08 PST 2017 From: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx> Date: Mon, 6 Feb 2017 18:10:31 -0200 Subject: sctp: avoid BUG_ON on sctp_wait_for_sndbuf From: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx> [ Upstream commit 2dcab598484185dea7ec22219c76dcdd59e3cb90 ] Alexander Popov reported that an application may trigger a BUG_ON in sctp_wait_for_sndbuf if the socket tx buffer is full, a thread is waiting on it to queue more data and meanwhile another thread peels off the association being used by the first thread. This patch replaces the BUG_ON call with a proper error handling. It will return -EPIPE to the original sendmsg call, similarly to what would have been done if the association wasn't found in the first place. Acked-by: Alexander Popov <alex.popov@xxxxxxxxx> Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx> Reviewed-by: Xin Long <lucien.xin@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/sctp/socket.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -7427,7 +7427,8 @@ static int sctp_wait_for_sndbuf(struct s */ release_sock(sk); current_timeo = schedule_timeout(current_timeo); - BUG_ON(sk != asoc->base.sk); + if (sk != asoc->base.sk) + goto do_error; lock_sock(sk); *timeo_p = current_timeo; Patches currently in stable-queue which might be from marcelo.leitner@xxxxxxxxx are queue-4.9/sctp-avoid-bug_on-on-sctp_wait_for_sndbuf.patch