------------[ cut here ]------------
WARNING: CPU: 0 PID: 5318 at fs/jfs/jfs_dmap.c:2875 dbAdjTree+0x454/0x4e0 fs/jfs/jfs_dmap.c:2875
Modules linked in:
CPU: 0 UID: 0 PID: 5318 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:dbAdjTree+0x454/0x4e0 fs/jfs/jfs_dmap.c:2875
Code: 5a ff ff ff e8 bd 6d 7a fe eb 05 e8 b6 6d 7a fe 48 83 c4 28 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 9d 6d 7a fe 90 <0f> 0b 90 eb e1 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c e1 fb ff ff
RSP: 0018:ffffc9000d267080 EFLAGS: 00010287
RAX: ffffffff8345a5b3 RBX: ffff88804203e010 RCX: 0000000000100000
RDX: ffffc9000e713000 RSI: 000000000000e032 RDI: 000000000000e033
RBP: 0000000000002057 R08: 0000000000000000 R09: 1ffffd40002101f0
R10: dffffc0000000000 R11: fffff940002101f1 R12: ffff88804203e018
R13: dffffc0000000000 R14: 0000000000000005 R15: 0000000000000155
FS:  00007f847b1b16c0(0000) GS:ffff88808d72f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000013000 CR3: 000000001fd77000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 dbSplit+0x132/0x200 fs/jfs/jfs_dmap.c:2648
 dbAllocBits+0x502/0xa60 fs/jfs/jfs_dmap.c:2193
 dbAllocDmap+0x6b/0x150 fs/jfs/jfs_dmap.c:2034
 dbAlloc+0x469/0xba0 fs/jfs/jfs_dmap.c:805
 extBalloc fs/jfs/jfs_extent.c:336 [inline]
 extAlloc+0x54a/0xfb0 fs/jfs/jfs_extent.c:127
 jfs_get_block+0x346/0xab0 fs/jfs/inode.c:254
 __block_write_begin_int+0x6b5/0x1900 fs/buffer.c:2145
 block_write_begin+0x8a/0x120 fs/buffer.c:2256
 jfs_write_begin+0x35/0x80 fs/jfs/inode.c:306
 generic_perform_write+0x2c5/0x900 mm/filemap.c:4254
 generic_file_write_iter+0x117/0x550 mm/filemap.c:4397
 do_iter_readv_writev+0x623/0x8c0 fs/read_write.c:-1
 vfs_writev+0x31a/0x960 fs/read_write.c:1057
 do_pwritev fs/read_write.c:1153 [inline]
 __do_sys_pwritev2 fs/read_write.c:1211 [inline]
 __se_sys_pwritev2+0x179/0x290 fs/read_write.c:1202
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f847a38f749
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:00007f847b1b1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000148
RAX: ffffffffffffffda RBX: 00007f847a5e6090 RCX: 00007f847a38f749
RDX: 0000000000000001 RSI: 0000200000000180 RDI: 0000000000000004
RBP: 00007f847a413f91 R08: 0000000000000000 R09: 0000000000000015
R10: 0000000000000007 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f847a5e6128 R14: 00007f847a5e6090 R15: 00007ffd46c13048
 </TASK>