------------[ cut here ]------------ DEBUG_RWSEMS_WARN_ON((rwsem_owner(sem) != current) && !rwsem_test_oflags(sem, RWSEM_NONSPINNABLE)): count = 0x0, magic = 0xffff888067f41b58, owner = 0x0, curr 0xffff888034191e40, list empty WARNING: kernel/locking/rwsem.c:1381 at __up_write kernel/locking/rwsem.c:1380 [inline], CPU#1: syz.1.548/8917 WARNING: kernel/locking/rwsem.c:1381 at up_write+0x2d6/0x410 kernel/locking/rwsem.c:1643, CPU#1: syz.1.548/8917 Modules linked in: CPU: 1 UID: 0 PID: 8917 Comm: syz.1.548 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:__up_write kernel/locking/rwsem.c:1380 [inline] RIP: 0010:up_write+0x388/0x410 kernel/locking/rwsem.c:1643 Code: cc 8b 49 c7 c2 c0 fb cc 8b 4c 0f 44 d0 48 8b 7c 24 08 48 c7 c6 20 fe cc 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 ea 8e 02 03 e9 67 fd ff ff 48 c7 c1 RSP: 0018:ffffc9000e71fc20 EFLAGS: 00010246 RAX: ffffffff8bccfba0 RBX: ffff888067f41b58 RCX: ffff888067f41b58 RDX: 0000000000000000 RSI: ffffffff8bccfe20 RDI: ffffffff90144210 RBP: ffff888067f41bb0 R08: 0000000000000000 R09: ffff888034191e40 R10: ffffffff8bccfba0 R11: ffffed100cfe836d R12: 0000000000000000 R13: dffffc0000000000 R14: ffff888067f41b58 R15: 1ffff1100cfe836c FS: 00007f4406cbb6c0(0000) GS:ffff8881255a0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000557053d5a138 CR3: 0000000049d89000 CR4: 0000000000350ef0 Call Trace: inode_unlock include/linux/fs.h:1038 [inline] chown_common+0x471/0x6b0 fs/open.c:780 do_fchownat+0x14c/0x250 fs/open.c:806 __do_sys_fchownat fs/open.c:821 [inline] __se_sys_fchownat fs/open.c:818 [inline] __x64_sys_fchownat+0xb5/0xd0 fs/open.c:818 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4405d9bf79 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4406cbb028 EFLAGS: 00000246 ORIG_RAX: 0000000000000104 RAX: ffffffffffffffda RBX: 00007f4406016270 RCX: 00007f4405d9bf79 RDX: 0000000000000000 RSI: 0000200000000000 RDI: ffffffffffffff9c RBP: 00007f4405e327e0 R08: 0000000000000100 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4406016308 R14: 00007f4406016270 R15: 00007ffee7e40008 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 49 c7 c2 c0 fb cc 8b mov $0xffffffff8bccfbc0,%r10 7: 4c 0f 44 d0 cmove %rax,%r10 b: 48 8b 7c 24 08 mov 0x8(%rsp),%rdi 10: 48 c7 c6 20 fe cc 8b mov $0xffffffff8bccfe20,%rsi 17: 48 8b 14 24 mov (%rsp),%rdx 1b: 4c 89 f1 mov %r14,%rcx 1e: 4d 89 e0 mov %r12,%r8 21: 4c 8b 4c 24 10 mov 0x10(%rsp),%r9 26: 41 52 push %r10 * 28: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2d: 48 83 c4 08 add $0x8,%rsp 31: e8 ea 8e 02 03 call 0x3028f20 36: e9 67 fd ff ff jmp 0xfffffda2 3b: 48 rex.W 3c: c7 .byte 0xc7 3d: c1 .byte 0xc1