Patchwork tun: add a missing nf_reset() in tun_net_xmit()

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Submitter Eric Dumazet
Date March 6, 2013, 9:02 p.m.
Message ID <1362603757.15793.186.camel@edumazet-glaptop>
Download mbox | patch
Permalink /patch/225653/
State Accepted
Delegated to: David Miller
Headers show

Comments

Eric Dumazet - March 6, 2013, 9:02 p.m.
From: Eric Dumazet <edumazet@google.com>

Dave reported following crash :

general protection fault: 0000 [#1] SMP 
CPU 2 
Pid: 25407, comm: qemu-kvm Not tainted 3.7.9-205.fc18.x86_64 #1 Hewlett-Packard HP Z400 Workstation/0B4Ch
RIP: 0010:[<ffffffffa0399bd5>]  [<ffffffffa0399bd5>] destroy_conntrack+0x35/0x120 [nf_conntrack]
RSP: 0018:ffff880276913d78  EFLAGS: 00010206
RAX: 50626b6b7876376c RBX: ffff88026e530d68 RCX: ffff88028d158e00
RDX: ffff88026d0d5470 RSI: 0000000000000011 RDI: 0000000000000002
RBP: ffff880276913d88 R08: 0000000000000000 R09: ffff880295002900
R10: 0000000000000000 R11: 0000000000000003 R12: ffffffff81ca3b40
R13: ffffffff8151a8e0 R14: ffff880270875000 R15: 0000000000000002
FS:  00007ff3bce38a00(0000) GS:ffff88029fc40000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 00007fd1430bd000 CR3: 000000027042b000 CR4: 00000000000027e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process qemu-kvm (pid: 25407, threadinfo ffff880276912000, task ffff88028c369720)
Stack:
 ffff880156f59100 ffff880156f59100 ffff880276913d98 ffffffff815534f7
 ffff880276913db8 ffffffff8151a74b ffff880270875000 ffff880156f59100
 ffff880276913dd8 ffffffff8151a5a6 ffff880276913dd8 ffff88026d0d5470
Call Trace:
 [<ffffffff815534f7>] nf_conntrack_destroy+0x17/0x20
 [<ffffffff8151a74b>] skb_release_head_state+0x7b/0x100
 [<ffffffff8151a5a6>] __kfree_skb+0x16/0xa0
 [<ffffffff8151a666>] kfree_skb+0x36/0xa0
 [<ffffffff8151a8e0>] skb_queue_purge+0x20/0x40
 [<ffffffffa02205f7>] __tun_detach+0x117/0x140 [tun]
 [<ffffffffa022184c>] tun_chr_close+0x3c/0xd0 [tun]
 [<ffffffff8119669c>] __fput+0xec/0x240
 [<ffffffff811967fe>] ____fput+0xe/0x10
 [<ffffffff8107eb27>] task_work_run+0xa7/0xe0
 [<ffffffff810149e1>] do_notify_resume+0x71/0xb0
 [<ffffffff81640152>] int_signal+0x12/0x17
Code: 00 00 04 48 89 e5 41 54 53 48 89 fb 4c 8b a7 e8 00 00 00 0f 85 de 00 00 00 0f b6 73 3e 0f b7 7b 2a e8 10 40 00 00 48 85 c0 74 0e <48> 8b 40 28 48 85 c0 74 05 48 89 df ff d0 48 c7 c7 08 6a 3a a0 
RIP  [<ffffffffa0399bd5>] destroy_conntrack+0x35/0x120 [nf_conntrack]
 RSP <ffff880276913d78>

This is because tun_net_xmit() needs to call nf_reset()
before queuing skb into receive_queue

Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 drivers/net/tun.c |    2 ++
 1 file changed, 2 insertions(+)



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David Miller - March 6, 2013, 9:05 p.m.
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 06 Mar 2013 13:02:37 -0800

> From: Eric Dumazet <edumazet@google.com>
> 
> Dave reported following crash :
 ...
> This is because tun_net_xmit() needs to call nf_reset()
> before queuing skb into receive_queue
> 
> Reported-by: Dave Jones <davej@redhat.com>
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Applied and queued up for -stable, thanks everyone.
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Patch

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 2c6a22e..b7c457a 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -747,6 +747,8 @@  static netdev_tx_t tun_net_xmit(struct sk_buff *skb, struct net_device *dev)
 		goto drop;
 	skb_orphan(skb);
 
+	nf_reset(skb);
+
 	/* Enqueue packet */
 	skb_queue_tail(&tfile->socket.sk->sk_receive_queue, skb);