UFO tlock:0xffffc9000103b120
BUG at fs/jfs/jfs_txnmgr.c:663 assert(last)
------------[ cut here ]------------
kernel BUG at fs/jfs/jfs_txnmgr.c:663!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5325 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 04/01/2014
RIP: 0010:txLock+0x1bdb/0x1d10 fs/jfs/jfs_txnmgr.c:663
Code: e9 c5 f7 ff ff e8 05 8f 56 fe 48 c7 c7 e0 b8 4d 8c 48 c7 c6 d9 b4 4d 8c ba 97 02 00 00 48 c7 c1 00 ba 4d 8c e8 d6 18 b7 fd 90 <0f> 0b e8 de 8e 56 fe 48 c7 c7 c0 ba 4d 8c e8 c2 18 b7 fd 48 c7 c7
RSP: 0018:ffffc9000dc56040 EFLAGS: 00010246
RAX: 000000000000002b RBX: 0000000000000000 RCX: d7356f5c32b25a00
RDX: 0000000000000000 RSI: 8000000000000000 RDI: 0000000000000000
RBP: ffffc9000dc56170 R08: ffffc9000dc55dc7 R09: 1ffff92001b8abb8
R10: dffffc0000000000 R11: fffff52001b8abb9 R12: 0000000000000000
R13: ffffc9000103b000 R14: 0000000000000000 R15: 1ffff92000207600
FS:  00007f79986c36c0(0000) GS:ffff88808c30a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f79986609a0 CR3: 000000001fdce000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 diWrite+0x444/0x1f60 fs/jfs/jfs_imap.c:654
 txCommit+0x83a/0x54a0 fs/jfs/jfs_txnmgr.c:1257
 jfs_commit_inode+0x2ef/0x530 fs/jfs/inode.c:114
 extAlloc+0xc82/0x1010 fs/jfs/jfs_extent.c:177
 jfs_get_block+0x351/0xad0 fs/jfs/inode.c:254
 __block_write_begin_int+0x6c2/0x1900 fs/buffer.c:2030
 block_write_begin+0x8d/0x120 fs/buffer.c:2144
 jfs_write_begin+0x35/0x80 fs/jfs/inode.c:306
 generic_perform_write+0x2d5/0x8f0 mm/filemap.c:4374
 generic_file_write_iter+0xae/0x330 mm/filemap.c:4517
 __kernel_write_iter+0x44a/0x8f0 fs/read_write.c:621
 dump_emit_page fs/coredump.c:1293 [inline]
 dump_user_range+0xc19/0x12c0 fs/coredump.c:1367
 elf_core_dump+0x3485/0x3a90 fs/binfmt_elf.c:2106
 coredump_write+0x1290/0x1960 fs/coredump.c:1047
 do_coredump fs/coredump.c:1126 [inline]
 vfs_coredump+0x3766/0x4530 fs/coredump.c:1195
 get_signal+0x1094/0x12c0 kernel/signal.c:3031
 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
 exit_to_user_mode_loop+0x10e/0x770 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline]
 ret_from_fork+0x593/0xb70 arch/x86/kernel/process.c:167
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---