------------[ cut here ]------------
WARNING: CPU: 1 PID: 6949 at fs/jfs/jfs_dmap.c:2875 dbAdjTree+0x454/0x4e0
Modules linked in:
CPU: 1 UID: 0 PID: 6949 Comm: syz.0.120 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:dbAdjTree+0x454/0x4e0
Code: 5a ff ff ff e8 bd 1f 81 fe eb 05 e8 b6 1f 81 fe 48 83 c4 28 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 9d 1f 81 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:ffffc90002aeeda0 EFLAGS: 00010283
RAX: ffffffff833e8e73 RBX: ffff88812c91e010 RCX: 0000000000080000
RDX: ffffc90003cb2000 RSI: 000000000000db7e RDI: 000000000000db7f
RBP: 0000000000002057 R08: 0000000000000000 R09: 1ffffd40009648f0
R10: dffffc0000000000 R11: fffff940009648f1 R12: ffff88812c91e018
R13: dffffc0000000000 R14: 0000000000000005 R15: 0000000000000155
FS:  00007f76b0b426c0(0000) GS:ffff8881a3c18000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f76b0b21d58 CR3: 000000012ab8c000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 dbSplit+0x132/0x200
 dbAllocBits+0x502/0xa60
 dbAllocDmap+0x6b/0x150
 dbAlloc+0x469/0xba0
 extAlloc+0x54a/0xfb0
 jfs_get_block+0x346/0xab0
 __block_write_begin_int+0x6b5/0x1900
 block_write_begin+0x8a/0x120
 jfs_write_begin+0x35/0x80
 generic_perform_write+0x2c5/0x900
 generic_file_write_iter+0x117/0x550
 iter_file_splice_write+0x975/0x10e0
 direct_splice_actor+0x101/0x160
 splice_direct_to_actor+0x5a8/0xcc0
 do_splice_direct+0x181/0x270
 do_sendfile+0x4da/0x7e0
 __se_sys_sendfile64+0x13e/0x190
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f76afd8ebe9
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:00007f76b0b42038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f76affc5fa0 RCX: 00007f76afd8ebe9
RDX: 0000000000000000 RSI: 0000000000000007 RDI: 0000000000000008
RBP: 00007f76afe11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000003ffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f76affc6038 R14: 00007f76affc5fa0 R15: 00007fff7a240e48
 </TASK>
