From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:38298 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751040AbdCROL6 (ORCPT ); Sat, 18 Mar 2017 10:11:58 -0400 Subject: Patch "dccp: Unlock sock before calling sk_free()" has been added to the 4.9-stable tree To: acme@redhat.com Cc: , From: Date: Sat, 18 Mar 2017 22:07:02 +0800 Message-ID: <14898460227369@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled dccp: Unlock sock before calling sk_free() 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: dccp-unlock-sock-before-calling-sk_free.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 know about it. >>From foo@baz Sat Mar 18 22:03:25 CST 2017 From: Arnaldo Carvalho de Melo Date: Wed, 1 Mar 2017 16:35:07 -0300 Subject: dccp: Unlock sock before calling sk_free() From: Arnaldo Carvalho de Melo [ Upstream commit d5afb6f9b6bb2c57bd0c05e76e12489dc0d037d9 ] The code where sk_clone() came from created a new socket and locked it, but then, on the error path didn't unlock it. This problem stayed there for a long while, till b0691c8ee7c2 ("net: Unlock sock before calling sk_free()") fixed it, but unfortunately the callers of sk_clone() (now sk_clone_locked()) were not audited and the one in dccp_create_openreq_child() remained. Now in the age of the syskaller fuzzer, this was finally uncovered, as reported by Dmitry: ---- 8< ---- I've got the following report while running syzkaller fuzzer on 86292b33d4b7 ("Merge branch 'akpm' (patches from Andrew)") [ BUG: held lock freed! ] 4.10.0+ #234 Not tainted ------------------------- syz-executor6/6898 is freeing memory ffff88006286cac0-ffff88006286d3b7, with a lock still held there! (slock-AF_INET6){+.-...}, at: [] spin_lock include/linux/spinlock.h:299 [inline] (slock-AF_INET6){+.-...}, at: [] sk_clone_lock+0x3d9/0x12c0 net/core/sock.c:1504 5 locks held by syz-executor6/6898: #0: (sk_lock-AF_INET6){+.+.+.}, at: [] lock_sock include/net/sock.h:1460 [inline] #0: (sk_lock-AF_INET6){+.+.+.}, at: [] inet_stream_connect+0x44/0xa0 net/ipv4/af_inet.c:681 #1: (rcu_read_lock){......}, at: [] inet6_csk_xmit+0x12a/0x5d0 net/ipv6/inet6_connection_sock.c:126 #2: (rcu_read_lock){......}, at: [] __skb_unlink include/linux/skbuff.h:1767 [inline] #2: (rcu_read_lock){......}, at: [] __skb_dequeue include/linux/skbuff.h:1783 [inline] #2: (rcu_read_lock){......}, at: [] process_backlog+0x264/0x730 net/core/dev.c:4835 #3: (rcu_read_lock){......}, at: [] ip6_input_finish+0x0/0x1700 net/ipv6/ip6_input.c:59 #4: (slock-AF_INET6){+.-...}, at: [] spin_lock include/linux/spinlock.h:299 [inline] #4: (slock-AF_INET6){+.-...}, at: [] sk_clone_lock+0x3d9/0x12c0 net/core/sock.c:1504 Fix it just like was done by b0691c8ee7c2 ("net: Unlock sock before calling sk_free()"). Reported-by: Dmitry Vyukov Cc: Cong Wang Cc: Eric Dumazet Cc: Gerrit Renker Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/20170301153510.GE15145@kernel.org Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/dccp/minisocks.c | 1 + 1 file changed, 1 insertion(+) --- a/net/dccp/minisocks.c +++ b/net/dccp/minisocks.c @@ -122,6 +122,7 @@ struct sock *dccp_create_openreq_child(c /* It is still raw copy of parent, so invalidate * destructor and make plain sk_free() */ newsk->sk_destruct = NULL; + bh_unlock_sock(newsk); sk_free(newsk); return NULL; } Patches currently in stable-queue which might be from acme@redhat.com are queue-4.9/dccp-unlock-sock-before-calling-sk_free.patch