general protection fault in rxrpc_error_report

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 3b47fd5c Merge tag 'nfs-for-5.3-4' of git://git.linux-nfs...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=12e278c1600000
kernel config: https://syzkaller.appspot.com/x/.config?x=b89bb446a3faaba4
dashboard link: https://syzkaller.appspot.com/bug?extid=611164843bd48cc2190c
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1014304e600000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=134663de600000

The bug was bisected to:

commit 2baec2c3f854d1f79c7bb28386484e144e864a14
Author: David Howells <dhow...@redhat.com>
Date: Wed May 24 16:02:32 2017 +0000

rxrpc: Support network namespacing

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=15edda32600000
final crash: https://syzkaller.appspot.com/x/report.txt?x=17edda32600000
console output: https://syzkaller.appspot.com/x/log.txt?x=13edda32600000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+611164...@syzkaller.appspotmail.com
Fixes: 2baec2c3f854 ("rxrpc: Support network namespacing")

kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.3.0-rc7+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:rxrpc_lookup_peer_icmp_rcu net/rxrpc/peer_event.c:37 [inline]
RIP: 0010:rxrpc_error_report+0x23b/0x1a80 net/rxrpc/peer_event.c:175
Code: ff ff ff ba 24 00 00 00 31 f6 48 89 df e8 ed ff 0f fb 49 8d be 5c 02
00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48
89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 16
RSP: 0018:ffff8880a99174a0 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: ffff8880a9917500 RCX: 0000000000000000
RDX: 000000000000004b RSI: 0000000000000000 RDI: 000000000000025c
RBP: ffff8880a99175a0 R08: 0000000000000004 R09: ffff8880a9917500
R10: ffffed1015322ea4 R11: 0000000000000003 R12: ffff888098ca4d40
R13: ffff88808dce9330 R14: 0000000000000000 R15: ffff8880a9917640
FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004cde30 CR3: 0000000008c6d000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
sock_queue_err_skb+0x34c/0x7c0 net/core/skbuff.c:4401
ip_icmp_error+0x3e3/0x580 net/ipv4/ip_sockglue.c:415
__udp4_lib_err+0x609/0x1320 net/ipv4/udp.c:713
udp_err+0x25/0x30 net/ipv4/udp.c:723
icmp_socket_deliver+0x1ea/0x370 net/ipv4/icmp.c:768
icmp_unreach+0x34a/0xaa0 net/ipv4/icmp.c:885
icmp_rcv+0xede/0x15a0 net/ipv4/icmp.c:1067
ip_protocol_deliver_rcu+0x5a/0x8b0 net/ipv4/ip_input.c:204
ip_local_deliver_finish+0x23b/0x390 net/ipv4/ip_input.c:231
NF_HOOK include/linux/netfilter.h:305 [inline]
NF_HOOK include/linux/netfilter.h:299 [inline]
ip_local_deliver+0x1e9/0x520 net/ipv4/ip_input.c:252
dst_input include/net/dst.h:442 [inline]
ip_rcv_finish+0x1d9/0x2e0 net/ipv4/ip_input.c:413
NF_HOOK include/linux/netfilter.h:305 [inline]
NF_HOOK include/linux/netfilter.h:299 [inline]
ip_rcv+0xe8/0x3f0 net/ipv4/ip_input.c:523
__netif_receive_skb_one_core+0x113/0x1a0 net/core/dev.c:5004
__netif_receive_skb+0x2c/0x1d0 net/core/dev.c:5118
process_backlog+0x206/0x750 net/core/dev.c:5929
napi_poll net/core/dev.c:6352 [inline]
net_rx_action+0x4d6/0x1030 net/core/dev.c:6418
__do_softirq+0x262/0x98c kernel/softirq.c:292
run_ksoftirqd kernel/softirq.c:603 [inline]
run_ksoftirqd+0x8e/0x110 kernel/softirq.c:595
smpboot_thread_fn+0x6a3/0xa40 kernel/smpboot.c:165
kthread+0x361/0x430 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Modules linked in:
---[ end trace 7d3172ee2e4a713b ]---
RIP: 0010:rxrpc_lookup_peer_icmp_rcu net/rxrpc/peer_event.c:37 [inline]
RIP: 0010:rxrpc_error_report+0x23b/0x1a80 net/rxrpc/peer_event.c:175
Code: ff ff ff ba 24 00 00 00 31 f6 48 89 df e8 ed ff 0f fb 49 8d be 5c 02
00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48
89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 16
RSP: 0018:ffff8880a99174a0 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: ffff8880a9917500 RCX: 0000000000000000
RDX: 000000000000004b RSI: 0000000000000000 RDI: 000000000000025c
RBP: ffff8880a99175a0 R08: 0000000000000004 R09: ffff8880a9917500
R10: ffffed1015322ea4 R11: 0000000000000003 R12: ffff888098ca4d40
R13: ffff88808dce9330 R14: 0000000000000000 R15: ffff8880a9917640
FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004cde30 CR3: 0000000008c6d000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches