Sergey, Richard and Fabio reported an oops in ip_route_input_noref. e.g., from Richard:
[ 0.877040] BUG: unable to handle kernel NULL pointer dereference at 0000000000000056 [ 0.877597] IP: [<ffffffff8155b5e2>] ip_route_input_noref+0x1a2/0xb00 [ 0.877597] PGD 3fa14067 PUD 3fa6e067 PMD 0 [ 0.877597] Oops: 0000 [#1] SMP [ 0.877597] Modules linked in: virtio_net virtio_pci virtio_ring virtio [ 0.877597] CPU: 1 PID: 119 Comm: ifconfig Not tainted 4.2.0+ #1 [ 0.877597] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 0.877597] task: ffff88003fab0bc0 ti: ffff88003faa8000 task.ti: ffff88003faa8000 [ 0.877597] RIP: 0010:[<ffffffff8155b5e2>] [<ffffffff8155b5e2>] ip_route_input_noref+0x1a2/0xb00 [ 0.877597] RSP: 0018:ffff88003ed03ba0 EFLAGS: 00010202 [ 0.877597] RAX: 0000000000000046 RBX: 00000000ffffff8f RCX: 0000000000000020 [ 0.877597] RDX: ffff88003fab50b8 RSI: 0000000000000200 RDI: ffffffff8152b4b8 [ 0.877597] RBP: ffff88003ed03c50 R08: 0000000000000000 R09: 0000000000000000 [ 0.877597] R10: 0000000000000000 R11: 0000000000000000 R12: ffff88003fab6f00 [ 0.877597] R13: ffff88003fab5000 R14: 0000000000000000 R15: ffffffff81cb5600 [ 0.877597] FS: 00007f6de5751700(0000) GS:ffff88003ed00000(0000) knlGS:0000000000000000 [ 0.877597] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.877597] CR2: 0000000000000056 CR3: 000000003fa6d000 CR4: 00000000000006e0 [ 0.877597] Stack: [ 0.877597] 0000000000000000 0000000000000046 ffff88003fffa600 ffff88003ed03be0 [ 0.877597] ffff88003f9e2c00 697da8c0017da8c0 ffff880000000000 000000000007fd00 [ 0.877597] 0000000000000000 0000000000000046 0000000000000000 0000000400000000 [ 0.877597] Call Trace: [ 0.877597] <IRQ> [ 0.877597] [<ffffffff812bfa1f>] ? cpumask_next_and+0x2f/0x40 [ 0.877597] [<ffffffff8158e13c>] arp_process+0x39c/0x690 [ 0.877597] [<ffffffff8158e57e>] arp_rcv+0x13e/0x170 [ 0.877597] [<ffffffff8151feec>] __netif_receive_skb_core+0x60c/0xa00 [ 0.877597] [<ffffffff81515795>] ? __build_skb+0x25/0x100 [ 0.877597] [<ffffffff81515795>] ? __build_skb+0x25/0x100 [ 0.877597] [<ffffffff81521ff6>] __netif_receive_skb+0x16/0x70 [ 0.877597] [<ffffffff81522078>] netif_receive_skb_internal+0x28/0x90 [ 0.877597] [<ffffffff8152288f>] napi_gro_receive+0x7f/0xd0 [ 0.877597] [<ffffffffa0017906>] virtnet_receive+0x256/0x910 [virtio_net] [ 0.877597] [<ffffffffa0017fd8>] virtnet_poll+0x18/0x80 [virtio_net] [ 0.877597] [<ffffffff815234cd>] net_rx_action+0x1dd/0x2f0 [ 0.877597] [<ffffffff81053228>] __do_softirq+0x98/0x260 [ 0.877597] [<ffffffff8164969c>] do_softirq_own_stack+0x1c/0x30 The root cause is use of res.table uninitialized. Thanks to Nikolay for noticing the uninitialized use amongst the maze of gotos. Fixes: b7503e0cdb5d ("net: Add FIB table id to rtable") Reported-by: Sergey Senozhatsky <sergey.senozhatsky.w...@gmail.com> Reported-by: Richard Alpe <richard.a...@ericsson.com> Reported-by: Fabio Estevam <feste...@gmail.com> Signed-off-by: David Ahern <d...@cumulusnetworks.com> --- net/ipv4/route.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index da427a4a33fe..80f7c5b7b832 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1712,6 +1712,7 @@ static int ip_route_input_slow(struct sk_buff *skb, __be32 daddr, __be32 saddr, goto martian_source; res.fi = NULL; + res.table = NULL; if (ipv4_is_lbcast(daddr) || (saddr == 0 && daddr == 0)) goto brd_input; @@ -1834,6 +1835,7 @@ out: return err; RT_CACHE_STAT_INC(in_no_route); res.type = RTN_UNREACHABLE; res.fi = NULL; + res.table = NULL; goto local_input; /* -- 2.3.2 (Apple Git-55) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html