------------[ cut here ]------------
DEBUG_RWSEMS_WARN_ON(!is_rwsem_reader_owned(sem)): count = 0x0, magic = 0xffff888047995058, owner = 0x0, curr 0xffff88800025c980, list empty
WARNING: kernel/locking/rwsem.c:1354 at __up_read+0x4f9/0x670 kernel/locking/rwsem.c:1354, CPU#0: syz.0.0/5343
Modules linked in:
CPU: 0 UID: 0 PID: 5343 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_read+0x5df/0x670 kernel/locking/rwsem.c:1354
Code: 23 6b 8b 49 c7 c2 c0 23 6b 8b 4c 0f 44 d0 48 8b 7c 24 28 48 c7 c6 60 23 6b 8b 4c 89 ea 48 8b 4c 24 20 4d 89 f0 4d 89 f9 41 52 <67> 48 0f b9 3a 48 83 c4 08 e8 93 a2 ee 02 e9 6e fb ff ff 48 c7 c1
RSP: 0018:ffffc9000df67a18 EFLAGS: 00010246
RAX: ffffffff8b6b23a0 RBX: ffff888047995058 RCX: ffff888047995058
RDX: 0000000000000000 RSI: ffffffff8b6b2360 RDI: ffffffff8f858520
RBP: ffffc9000df67ae8 R08: 0000000000000000 R09: ffff88800025c980
R10: ffffffff8b6b23a0 R11: ffffed1008f32a0d R12: ffff8880479950b0
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88800025c980
FS: 00007f71f41cc6c0(0000) GS:ffff88808d414000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f71f41aafc8 CR3: 00000000377e7000 CR4: 0000000000352ef0
Call Trace:
<TASK>
inode_unlock_shared include/linux/fs.h:1052 [inline]
lookup_slow+0x5e/0x70 fs/namei.c:1876
walk_component fs/namei.c:2221 [inline]
lookup_last fs/namei.c:2722 [inline]
path_lookupat+0x3f5/0x8c0 fs/namei.c:2746
filename_lookup+0x212/0x570 fs/namei.c:2775
user_path_at+0x3a/0x60 fs/namei.c:3567
do_fchownat+0x105/0x270 fs/open.c:813
__do_sys_lchown fs/open.c:844 [inline]
__se_sys_lchown fs/open.c:842 [inline]
__x64_sys_lchown+0x85/0xa0 fs/open.c:842
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: 0033:0x7f71f7d8f7c9
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:00007f71f41cc038 EFLAGS: 00000246 ORIG_RAX: 000000000000005e
RAX: ffffffffffffffda RBX: 00007f71f7fe6090 RCX: 00007f71f7d8f7c9
RDX: 0000000000000000 RSI: 000000000000ee00 RDI: 00002000000000c0
RBP: 00007f71f7e13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f71f7fe6128 R14: 00007f71f7fe6090 R15: 00007fffef7848b8
</TASK>
----------------
Code disassembly (best guess):
0: 23 6b 8b and -0x75(%rbx),%ebp
3: 49 c7 c2 c0 23 6b 8b mov $0xffffffff8b6b23c0,%r10
a: 4c 0f 44 d0 cmove %rax,%r10
e: 48 8b 7c 24 28 mov 0x28(%rsp),%rdi
13: 48 c7 c6 60 23 6b 8b mov $0xffffffff8b6b2360,%rsi
1a: 4c 89 ea mov %r13,%rdx
1d: 48 8b 4c 24 20 mov 0x20(%rsp),%rcx
22: 4d 89 f0 mov %r14,%r8
25: 4d 89 f9 mov %r15,%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 93 a2 ee 02 call 0x2eea2cb
38: e9 6e fb ff ff jmp 0xfffffbab
3d: 48 rex.W
3e: c7 .byte 0xc7
3f: c1 .byte 0xc1