From: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx> 3.12-stable review patch. If anyone has any objections, please let me know. =============== [ 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: Jiri Slaby <jslaby@xxxxxxx> --- net/sctp/socket.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 2c5cb6d2787d..8e7cc3e2b08b 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -6712,7 +6712,8 @@ static int sctp_wait_for_sndbuf(struct sctp_association *asoc, long *timeo_p, */ sctp_release_sock(sk); current_timeo = schedule_timeout(current_timeo); - BUG_ON(sk != asoc->base.sk); + if (sk != asoc->base.sk) + goto do_error; sctp_lock_sock(sk); *timeo_p = current_timeo; -- 2.12.0