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| author | Eric Dumazet <edumazet@google.com> | 2016-11-02 20:21:20 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-11-03 16:16:51 -0400 |
| commit | 93636d1f1f162ae89ae4f2a22a83bf4fd960724e (patch) | |
| tree | b1e0a034e9453fa503c7b1da591d3ec213c0b52e /net/netlink | |
| parent | 6706a97fec963d6cb3f7fc2978ec1427b4651214 (diff) | |
| download | linux-93636d1f1f162ae89ae4f2a22a83bf4fd960724e.tar.gz linux-93636d1f1f162ae89ae4f2a22a83bf4fd960724e.tar.bz2 linux-93636d1f1f162ae89ae4f2a22a83bf4fd960724e.zip | |
netlink: netlink_diag_dump() runs without locks
A recent commit removed locking from netlink_diag_dump() but forgot
one error case.
=====================================
[ BUG: bad unlock balance detected! ]
4.9.0-rc3+ #336 Not tainted
-------------------------------------
syz-executor/4018 is trying to release lock ([ 36.220068] nl_table_lock
) at:
[<ffffffff82dc8683>] netlink_diag_dump+0x1a3/0x250 net/netlink/diag.c:182
but there are no more locks to release!
other info that might help us debug this:
3 locks held by syz-executor/4018:
#0: [ 36.220068] (
sock_diag_mutex[ 36.220068] ){+.+.+.}
, at: [ 36.220068] [<ffffffff82c3873b>] sock_diag_rcv+0x1b/0x40
#1: [ 36.220068] (
sock_diag_table_mutex[ 36.220068] ){+.+.+.}
, at: [ 36.220068] [<ffffffff82c38e00>] sock_diag_rcv_msg+0x140/0x3a0
#2: [ 36.220068] (
nlk->cb_mutex[ 36.220068] ){+.+.+.}
, at: [ 36.220068] [<ffffffff82db6600>] netlink_dump+0x50/0xac0
stack backtrace:
CPU: 1 PID: 4018 Comm: syz-executor Not tainted 4.9.0-rc3+ #336
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
ffff8800645df688 ffffffff81b46934 ffffffff84eb3e78 ffff88006ad85800
ffffffff82dc8683 ffffffff84eb3e78 ffff8800645df6b8 ffffffff812043ca
dffffc0000000000 ffff88006ad85ff8 ffff88006ad85fd0 00000000ffffffff
Call Trace:
[< inline >] __dump_stack lib/dump_stack.c:15
[<ffffffff81b46934>] dump_stack+0xb3/0x10f lib/dump_stack.c:51
[<ffffffff812043ca>] print_unlock_imbalance_bug+0x17a/0x1a0
kernel/locking/lockdep.c:3388
[< inline >] __lock_release kernel/locking/lockdep.c:3512
[<ffffffff8120cfd8>] lock_release+0x8e8/0xc60 kernel/locking/lockdep.c:3765
[< inline >] __raw_read_unlock ./include/linux/rwlock_api_smp.h:225
[<ffffffff83fc001a>] _raw_read_unlock+0x1a/0x30 kernel/locking/spinlock.c:255
[<ffffffff82dc8683>] netlink_diag_dump+0x1a3/0x250 net/netlink/diag.c:182
[<ffffffff82db6947>] netlink_dump+0x397/0xac0 net/netlink/af_netlink.c:2110
Fixes: ad202074320c ("netlink: Use rhashtable walk interface in diag dump")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/netlink')
| -rw-r--r-- | net/netlink/diag.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/net/netlink/diag.c b/net/netlink/diag.c index b2f0e986a6f4..a5546249fb10 100644 --- a/net/netlink/diag.c +++ b/net/netlink/diag.c @@ -178,11 +178,8 @@ static int netlink_diag_dump(struct sk_buff *skb, struct netlink_callback *cb) } cb->args[1] = i; } else { - if (req->sdiag_protocol >= MAX_LINKS) { - read_unlock(&nl_table_lock); - rcu_read_unlock(); + if (req->sdiag_protocol >= MAX_LINKS) return -ENOENT; - } err = __netlink_diag_dump(skb, cb, req->sdiag_protocol, s_num); } |