From 2b81f8161dfeda4017cef4f2498ccb64b13f0d61 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Wed, 29 May 2019 16:33:23 -0700 Subject: [PATCH] net: don't clear sock->sk early to avoid trouble in strparser af_inet sets sock->sk to NULL which trips strparser over: BUG: kernel NULL pointer dereference, address: 0000000000000012 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 7 PID: 0 Comm: swapper/7 Not tainted 5.2.0-rc1-00139-g14629453a6d3 #21 RIP: 0010:tcp_peek_len+0x10/0x60 RSP: 0018:ffffc02e41c54b98 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff9cf924c4e030 RCX: 0000000000000051 RDX: 0000000000000000 RSI: 000000000000000c RDI: ffff9cf97128f480 RBP: ffff9cf9365e0300 R08: ffff9cf94fe7d2c0 R09: 0000000000000000 R10: 000000000000036b R11: ffff9cf939735e00 R12: ffff9cf91ad9ae40 R13: ffff9cf924c4e000 R14: ffff9cf9a8fcbaae R15: 0000000000000020 FS: 0000000000000000(0000) GS:ffff9cf9af7c0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000012 CR3: 000000013920a003 CR4: 00000000003606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: strp_data_ready+0x48/0x90 tls_data_ready+0x22/0xd0 [tls] tcp_rcv_established+0x569/0x620 tcp_v4_do_rcv+0x127/0x1e0 tcp_v4_rcv+0xad7/0xbf0 ip_protocol_deliver_rcu+0x2c/0x1c0 ip_local_deliver_finish+0x41/0x50 ip_local_deliver+0x6b/0xe0 ? ip_protocol_deliver_rcu+0x1c0/0x1c0 ip_rcv+0x52/0xd0 ? ip_rcv_finish_core.isra.20+0x380/0x380 __netif_receive_skb_one_core+0x7e/0x90 netif_receive_skb_internal+0x42/0xf0 napi_gro_receive+0xed/0x150 nfp_net_poll+0x7a2/0xd30 [nfp] ? kmem_cache_free_bulk+0x286/0x310 net_rx_action+0x149/0x3b0 __do_softirq+0xe3/0x30a ? handle_irq_event_percpu+0x6a/0x80 irq_exit+0xe8/0xf0 do_IRQ+0x85/0xd0 common_interrupt+0xf/0xf RIP: 0010:cpuidle_enter_state+0xbc/0x450 To avoid this issue set sock->sk after sk_prot->close. My grepping and testing did not discover any code which would depend on the current behaviour. Fixes: c46234ebb4d1 ("tls: RX path for ktls") Reported-by: David Beckett Signed-off-by: Jakub Kicinski Reviewed-by: Dirk van der Merwe Signed-off-by: David S. Miller --- net/ipv4/af_inet.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 5183a2daba64..aff93e7cdb31 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -428,8 +428,8 @@ int inet_release(struct socket *sock) if (sock_flag(sk, SOCK_LINGER) && !(current->flags & PF_EXITING)) timeout = sk->sk_lingertime; - sock->sk = NULL; sk->sk_prot->close(sk, timeout); + sock->sk = NULL; } return 0; }