From 674ce0f35d6c917824ff772c9f87f6a1102192b2 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Mon, 12 Nov 2007 13:04:20 +0100 Subject: [PATCH] [INET_DIAG]: Fix oops in netlink_rcv_skb netlink_run_queue() doesn't handle multiple processes processing the queue concurrently. Serialize queue processing in inet_diag to fix a oops in netlink_rcv_skb caused by netlink_run_queue passing a NULL for the skb. BUG: unable to handle kernel NULL pointer dereference at virtual address 00000054 [349587.500454] printing eip: [349587.500457] c03318ae [349587.500459] *pde = 00000000 [349587.500464] Oops: 0000 [#1] [349587.500466] PREEMPT SMP [349587.500474] Modules linked in: w83627hf hwmon_vid i2c_isa [349587.500483] CPU: 0 [349587.500485] EIP: 0060:[] Not tainted VLI [349587.500487] EFLAGS: 00010246 (2.6.22.3 #1) [349587.500499] EIP is at netlink_rcv_skb+0xa/0x7e [349587.500506] eax: 00000000 ebx: 00000000 ecx: c148d2a0 edx: c0398819 [349587.500510] esi: 00000000 edi: c0398819 ebp: c7a21c8c esp: c7a21c80 [349587.500517] ds: 007b es: 007b fs: 00d8 gs: 0033 ss: 0068 [349587.500521] Process oidentd (pid: 17943, ti=c7a20000 task=cee231c0 task.ti=c7a20000) [349587.500527] Stack: 00000000 c7a21cac f7c8ba78 c7a21ca4 c0331962 c0398819 f7c8ba00 0000004c [349587.500542] f736f000 c7a21cb4 c03988e3 00000001 f7c8ba00 c7a21cc4 c03312a5 0000004c [349587.500558] f7c8ba00 c7a21cd4 c0330681 f7c8ba00 e4695280 c7a21d00 c03307c6 7fffffff [349587.500578] Call Trace: [349587.500581] [] show_trace_log_lvl+0x1c/0x33 [349587.500591] [] show_stack_log_lvl+0x8d/0xaa [349587.500595] [] show_registers+0x1cb/0x321 [349587.500604] [] die+0x112/0x1e1 [349587.500607] [] do_page_fault+0x229/0x565 [349587.500618] [] error_code+0x72/0x78 [349587.500625] [] netlink_run_queue+0x40/0x76 [349587.500632] [] inet_diag_rcv+0x1f/0x2c [349587.500639] [] netlink_data_ready+0x57/0x59 [349587.500643] [] netlink_sendskb+0x24/0x45 [349587.500651] [] netlink_unicast+0x100/0x116 [349587.500656] [] netlink_sendmsg+0x1c2/0x280 [349587.500664] [] sock_sendmsg+0xba/0xd5 [349587.500671] [] sys_sendmsg+0x17b/0x1e8 [349587.500676] [] sys_socketcall+0x230/0x24d [349587.500684] [] syscall_call+0x7/0xb [349587.500691] ======================= [349587.500693] Code: f0 ff 4e 18 0f 94 c0 84 c0 0f 84 66 ff ff ff 89 f0 e8 86 e2 fc ff e9 5a ff ff ff f0 ff 40 10 eb be 55 89 e5 57 89 d7 56 89 c6 53 <8b> 50 54 83 fa 10 72 55 8b 9e 9c 00 00 00 31 c9 8b 03 83 f8 0f Reported by Athanasius Adrian Bunk: Backported to 2.6.16 based on a suggestion by David S. Miller. Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller Signed-off-by: Adrian Bunk --- net/ipv4/inet_diag.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index 457db99c76df..29d2625b6488 100644 --- a/net/ipv4/inet_diag.c +++ b/net/ipv4/inet_diag.c @@ -856,15 +856,23 @@ static inline void inet_diag_rcv_skb(struct sk_buff *skb) } } +static DEFINE_MUTEX(inet_diag_mutex); + static void inet_diag_rcv(struct sock *sk, int len) { struct sk_buff *skb; - unsigned int qlen = skb_queue_len(&sk->sk_receive_queue); + unsigned int qlen; + + mutex_lock(&inet_diag_mutex); + + qlen = skb_queue_len(&sk->sk_receive_queue); while (qlen-- && (skb = skb_dequeue(&sk->sk_receive_queue))) { inet_diag_rcv_skb(skb); kfree_skb(skb); } + + mutex_unlock(&inet_diag_mutex); } static DEFINE_SPINLOCK(inet_diag_register_lock); -- 2.39.5