------------[ cut here ]------------
a->in_addr.ss_family == 512
WARNING: ./include/linux/ceph/decode.h:238 at ceph_decode_banner_addr include/linux/ceph/decode.h:238 [inline], CPU#1: kworker/1:4/5846
WARNING: ./include/linux/ceph/decode.h:238 at read_partial_banner net/ceph/messenger_v1.c:632 [inline], CPU#1: kworker/1:4/5846
WARNING: ./include/linux/ceph/decode.h:238 at ceph_con_v1_try_read+0x54e2/0x6ca0 net/ceph/messenger_v1.c:1339, CPU#1: kworker/1:4/5846
Modules linked in:
CPU: 1 UID: 0 PID: 5846 Comm: kworker/1:4 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Workqueue: ceph-msgr ceph_con_workfn
RIP: 0010:ceph_decode_banner_addr include/linux/ceph/decode.h:238 [inline]
RIP: 0010:read_partial_banner net/ceph/messenger_v1.c:632 [inline]
RIP: 0010:ceph_con_v1_try_read+0x54e2/0x6ca0 net/ceph/messenger_v1.c:1339
Code: 3c 02 00 0f 85 9c 03 00 00 48 c7 c0 60 c7 48 8d e9 c8 c7 ff ff 48 8b 7c 24 10 e8 49 01 fb f6 e9 e0 af ff ff e8 4f 77 8a f6 90 <0f> 0b 90 e9 06 ee ff ff e8 41 77 8a f6 31 f6 bf 00 0c 00 00 e8 55
RSP: 0018:ffffc90003e8fa08 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffff88802e0bc73c RCX: ffffffff8b7fd8d5
RDX: ffff88802d060000 RSI: ffffffff8b7fead1 RDI: ffff88802d060000
RBP: ffff88802e0bc75a R08: 0000000000000003 R09: 0000000000000002
R10: 0000000000000002 R11: 0000000000000000 R12: ffff88802e0bc418
R13: 0000000000000002 R14: 0000000000000091 R15: ffffed1005c17887
FS:  0000000000000000(0000) GS:ffff8880d5ed8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c37e6bb CR3: 0000000056b1e000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 ceph_con_workfn+0x9a5/0x13e0 net/ceph/messenger.c:1577
 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
 process_scheduled_works kernel/workqueue.c:3405 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>