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DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff88805488d058, owner = 0x0, curr 0xffff888000abc980, list empty
WARNING: kernel/locking/rwsem.c:1381 at __up_write kernel/locking/rwsem.c:1380 [inline], CPU#0: syz.0.0/5344
WARNING: kernel/locking/rwsem.c:1381 at up_write+0x2d8/0x410 kernel/locking/rwsem.c:1643, CPU#0: syz.0.0/5344
Modules linked in:
CPU: 0 UID: 0 PID: 5344 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:__up_write kernel/locking/rwsem.c:1380 [inline]
RIP: 0010:up_write+0x38a/0x410 kernel/locking/rwsem.c:1643
Code: 6b 8b 49 c7 c2 c0 23 6b 8b 4c 0f 44 d0 48 8b 7c 24 08 48 c7 c6 e0 24 6b 8b 48 8b 14 24 4c 89 f1 4d 89 e0 4c 8b 4c 24 10 41 52 <67> 48 0f b9 3a 48 83 c4 08 e8 18 99 ee 02 e9 66 fd ff ff 48 c7 c1
RSP: 0018:ffffc9000e47fc20 EFLAGS: 00010246
RAX: ffffffff8b6b23a0 RBX: ffff88805488d058 RCX: ffff88805488d058
RDX: 0000000000000000 RSI: ffffffff8b6b24e0 RDI: ffffffff8f858140
RBP: ffff88805488d0b0 R08: 0000000000000000 R09: ffff888000abc980
R10: ffffffff8b6b23a0 R11: ffffed100a911a0d R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88805488d058 R15: 1ffff1100a911a0c
FS:  00007fa957a816c0(0000) GS:ffff88808d416000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa957a80fc8 CR3: 0000000040996000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 inode_unlock include/linux/fs.h:1037 [inline]
 chown_common+0x418/0x5b0 fs/open.c:790
 do_fchownat+0x161/0x270 fs/open.c:819
 __do_sys_fchownat fs/open.c:834 [inline]
 __se_sys_fchownat fs/open.c:831 [inline]
 __x64_sys_fchownat+0xb5/0xd0 fs/open.c:831
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa956b8f7c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa957a81038 EFLAGS: 00000246 ORIG_RAX: 0000000000000104
RAX: ffffffffffffffda RBX: 00007fa956de6090 RCX: 00007fa956b8f7c9
RDX: 0000000000004000 RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007fa956c13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa956de6128 R14: 00007fa956de6090 R15: 00007ffcb6621a98
 </TASK>
----------------
Code disassembly (best guess):
   0:	6b 8b 49 c7 c2 c0 23 	imul   $0x23,-0x3f3d38b7(%rbx),%ecx
   7:	6b 8b 4c 0f 44 d0 48 	imul   $0x48,-0x2fbbf0b4(%rbx),%ecx
   e:	8b 7c 24 08          	mov    0x8(%rsp),%edi
  12:	48 c7 c6 e0 24 6b 8b 	mov    $0xffffffff8b6b24e0,%rsi
  19:	48 8b 14 24          	mov    (%rsp),%rdx
  1d:	4c 89 f1             	mov    %r14,%rcx
  20:	4d 89 e0             	mov    %r12,%r8
  23:	4c 8b 4c 24 10       	mov    0x10(%rsp),%r9
  28:	41 52                	push   %r10
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	48 83 c4 08          	add    $0x8,%rsp
  33:	e8 18 99 ee 02       	call   0x2ee9950
  38:	e9 66 fd ff ff       	jmp    0xfffffda3
  3d:	48                   	rex.W
  3e:	c7                   	.byte 0xc7
  3f:	c1                   	.byte 0xc1