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| author | Pablo Neira Ayuso <pablo@netfilter.org> | 2015-12-09 12:09:56 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2015-12-10 18:16:29 +0100 |
| commit | bd678e09dc1797bc0e2e536b6b268e7cf46e0184 (patch) | |
| tree | 52a65974a9f6085f6c3e063d0b03c906fe46c433 /net/netfilter/nfnetlink.c | |
| parent | 633c9a840d0bf1cce690f3165bdacd8ab412949e (diff) | |
| download | linux-bd678e09dc1797bc0e2e536b6b268e7cf46e0184.tar.gz linux-bd678e09dc1797bc0e2e536b6b268e7cf46e0184.tar.xz | |
netfilter: nfnetlink: fix splat due to incorrect socket memory accounting in skbuff clones
If we attach the sk to the skb from nfnetlink_rcv_batch(), then
netlink_skb_destructor() will underflow the socket receive memory
counter and we get warning splat when releasing the socket.
$ cat /proc/net/netlink
sk Eth Pid Groups Rmem Wmem Dump Locks Drops Inode
ffff8800ca903000 12 0 00000000 -54144 0 0 2 0 17942
^^^^^^
Rmem above shows an underflow.
And here below the warning splat:
[ 1363.815976] WARNING: CPU: 2 PID: 1356 at net/netlink/af_netlink.c:958 netlink_sock_destruct+0x80/0xb9()
[...]
[ 1363.816152] CPU: 2 PID: 1356 Comm: kworker/u16:1 Tainted: G W 4.4.0-rc1+ #153
[ 1363.816155] Hardware name: LENOVO 23259H1/23259H1, BIOS G2ET32WW (1.12 ) 05/30/2012
[ 1363.816160] Workqueue: netns cleanup_net
[ 1363.816163] 0000000000000000 ffff880119203dd0 ffffffff81240204 0000000000000000
[ 1363.816169] ffff880119203e08 ffffffff8104db4b ffffffff813d49a1 ffff8800ca771000
[ 1363.816174] ffffffff81a42b00 0000000000000000 ffff8800c0afe1e0 ffff880119203e18
[ 1363.816179] Call Trace:
[ 1363.816181] <IRQ> [<ffffffff81240204>] dump_stack+0x4e/0x79
[ 1363.816193] [<ffffffff8104db4b>] warn_slowpath_common+0x9a/0xb3
[ 1363.816197] [<ffffffff813d49a1>] ? netlink_sock_destruct+0x80/0xb9
skb->sk was only needed to lookup for the netns, however we don't need
this anymore since 633c9a840d0b ("netfilter: nfnetlink: avoid recurrent
netns lookups in call_batch") so this patch removes this manual socket
assignment to resolve this problem.
Reported-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Tested-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Diffstat (limited to 'net/netfilter/nfnetlink.c')
| -rw-r--r-- | net/netfilter/nfnetlink.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c index 445590f2c673..77afe913d03d 100644 --- a/net/netfilter/nfnetlink.c +++ b/net/netfilter/nfnetlink.c @@ -295,8 +295,6 @@ replay: if (!skb) return netlink_ack(oskb, nlh, -ENOMEM); - skb->sk = oskb->sk; - nfnl_lock(subsys_id); ss = rcu_dereference_protected(table[subsys_id].subsys, lockdep_is_held(&table[subsys_id].mutex)); |