From: Eric Dumazet <edumazet@google.com>
Date: Sun, 24 Jan 2016 21:53:50 +0000 (-0800)
Subject: af_unix: fix struct pid memory leak
X-Git-Tag: v2.6.32.71~40
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2a890807f49093b129357e830e8dd949e3eb4514;p=thirdparty%2Fkernel%2Fstable.git

af_unix: fix struct pid memory leak

commit fa0dc04df259ba2df3ce1920e9690c7842f8fa4b upstream.

Dmitry reported a struct pid leak detected by a syzkaller program.

Bug happens in unix_stream_recvmsg() when we break the loop when a
signal is pending, without properly releasing scm.

Fixes: b3ca9b02b007 ("net: fix multithreaded signal handling in unix recv routines")
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Rainer Weikusat <rweikusat@mobileactivedefense.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Ben Hutchings <ben@decadent.org.uk>
[wt: note, according to Rainer & Ben the bug was really introduced in
 2.5.65, not by the commit mentionned in Fixes. 2.6.32 uses siocb->scm
 instead of scm]
Signed-off-by: Willy Tarreau <w@1wt.eu>
---

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 8e6a609ee4fb1..67f50be0cc2a1 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -2018,6 +2018,7 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
 
 			if (signal_pending(current)) {
 				err = sock_intr_errno(timeo);
+				scm_destroy(siocb->scm);
 				goto out;
 			}
 			mutex_lock(&u->readlock);