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| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2017-03-01 20:35:07 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-03-02 22:19:33 +0100 |
| commit | d5afb6f9b6bb2c57bd0c05e76e12489dc0d037d9 (patch) | |
| tree | e5f906ec5ee8afa095bb56a1669ad4ff177c62c9 | |
| parent | Merge tag 'batadv-net-for-davem-20170301' of git://git.open-mesh.org/linux-merge (diff) | |
| download | linux-d5afb6f9b6bb2c57bd0c05e76e12489dc0d037d9.tar.xz linux-d5afb6f9b6bb2c57bd0c05e76e12489dc0d037d9.zip | |
dccp: Unlock sock before calling sk_free()
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: [<ffffffff8362c2c9>] spin_lock
include/linux/spinlock.h:299 [inline]
(slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>]
sk_clone_lock+0x3d9/0x12c0 net/core/sock.c:1504
5 locks held by syz-executor6/6898:
#0: (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff839a34b4>] lock_sock
include/net/sock.h:1460 [inline]
#0: (sk_lock-AF_INET6){+.+.+.}, at: [<ffffffff839a34b4>]
inet_stream_connect+0x44/0xa0 net/ipv4/af_inet.c:681
#1: (rcu_read_lock){......}, at: [<ffffffff83bc1c2a>]
inet6_csk_xmit+0x12a/0x5d0 net/ipv6/inet6_connection_sock.c:126
#2: (rcu_read_lock){......}, at: [<ffffffff8369b424>] __skb_unlink
include/linux/skbuff.h:1767 [inline]
#2: (rcu_read_lock){......}, at: [<ffffffff8369b424>] __skb_dequeue
include/linux/skbuff.h:1783 [inline]
#2: (rcu_read_lock){......}, at: [<ffffffff8369b424>]
process_backlog+0x264/0x730 net/core/dev.c:4835
#3: (rcu_read_lock){......}, at: [<ffffffff83aeb5c0>]
ip6_input_finish+0x0/0x1700 net/ipv6/ip6_input.c:59
#4: (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>] spin_lock
include/linux/spinlock.h:299 [inline]
#4: (slock-AF_INET6){+.-...}, at: [<ffffffff8362c2c9>]
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 <dvyukov@google.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170301153510.GE15145@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | net/dccp/minisocks.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/net/dccp/minisocks.c b/net/dccp/minisocks.c index 53eddf99e4f6..d20d948a98ed 100644 --- a/net/dccp/minisocks.c +++ b/net/dccp/minisocks.c @@ -122,6 +122,7 @@ struct sock *dccp_create_openreq_child(const struct sock *sk, /* 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; } |