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
Dumping ftrace buffer:
   (ftrace buffer empty)
Modules linked in:
CPU: 1 PID: 11705 Comm: syz-executor3 Not tainted 4.9.123-g8dd3fc2 #79
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801cc4f6000 task.stack: ffff8801cb580000
RIP: 0010:[<ffffffff8301ceec>]  [<ffffffff8301ceec>] sockfs_setattr+0xbc/0x140 net/socket.c:544
RSP: 0018:ffff8801cb587c48  EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffff8801cb587d90 RCX: 0000000000000000
RDX: 0000000000000065 RSI: ffffffff8301ce8e RDI: 0000000000000328
RBP: ffff8801cb587c60 R08: ffffed00396b0f4d R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000003 R12: 0000000000000000
R13: 0000000000000000 R14: ffff8801c535de40 R15: 0000000000000000
FS:  00007fac7df39700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc2ce1f2518 CR3: 00000001b9a23000 CR4: 00000000001606f0
Stack:
 0000000000001846 ffffffff8301ce30 ffff8801cb587d90 ffff8801cb587ce0
 ffffffff815d8630 ffff8801c515fbb0 ffff8801cb587cb8 ffff8801c535de98
 ffff8801cb587d50 0000000000000004 0000000003996300 ffff8801d9922e20
Call Trace:
 [<ffffffff815d8630>] notify_change2+0xac0/0xdf0 fs/attr.c:313
 [<ffffffff8156ddb2>] chown_common+0x482/0x550 fs/open.c:629
 [<ffffffff815716c5>] SYSC_fchownat fs/open.c:659 [inline]
 [<ffffffff815716c5>] SyS_fchownat+0x115/0x1b0 fs/open.c:639
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff83a01c93>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: fa 48 c1 ea 03 80 3c 02 00 0f 85 87 00 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6d f0 49 8d bd 28 03 00 00 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 04 3c 03 7e 47 48 8d 7b 08 48 b8 00 00 00 
RIP  [<ffffffff8301ceec>] sockfs_setattr+0xbc/0x140 net/socket.c:544
 RSP <ffff8801cb587c48>
---[ end trace 4bb0411f3071bb15 ]---