loop0: detected capacity change from 0 to 32768
loop0: detected capacity change from 32768 to 32767
BUG at fs/jfs/jfs_dmap.c:3070 assert(n < 4)
------------[ cut here ]------------
kernel BUG at fs/jfs/jfs_dmap.c:3070!
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:dbFindLeaf+0x519/0x520 fs/jfs/jfs_dmap.c:3070
Code: e9 4e ff ff ff e8 c7 8a 5e fe 48 c7 c7 a0 59 2c 8c 48 c7 c6 e0 56 2c 8c ba fe 0b 00 00 48 c7 c1 c0 64 2c 8c e8 a8 27 bf fd 90 <0f> 0b 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000f997618 EFLAGS: 00010246
RAX: 000000000000002b RBX: 00000000ffffffff RCX: f1ce9ed415c15400
RDX: ffffc9000f0aa000 RSI: 0000000000000dd0 RDI: 0000000000000dd1
RBP: 000000000a04ffff R08: ffffc9000f9973a7 R09: 1ffff92001f32e74
R10: dffffc0000000000 R11: fffff52001f32e75 R12: 0000000000000000
R13: 000000000000000d R14: 0000000000000010 R15: 0000000000000155
FS:  00007f335fb996c0(0000) GS:ffff88808c540000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f12133b3000 CR3: 000000001d3b8000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 dbAllocDmapLev+0x60/0x3b0 fs/jfs/jfs_dmap.c:2056
 dbAllocCtl+0x145/0x990 fs/jfs/jfs_dmap.c:1912
 dbAllocAG+0x1f4/0xf80 fs/jfs/jfs_dmap.c:1440
 dbAlloc+0x5ab/0xba0 fs/jfs/jfs_dmap.c:964
 diNewIAG fs/jfs/jfs_imap.c:2510 [inline]
 diAllocExt fs/jfs/jfs_imap.c:1905 [inline]
 diAllocAG+0xaaa/0x1de0 fs/jfs/jfs_imap.c:1669
 diAlloc+0x1e2/0x16b0 fs/jfs/jfs_imap.c:1590
 ialloc+0x8c/0x8e0 fs/jfs/jfs_inode.c:56
 jfs_mkdir+0x1e4/0xb00 fs/jfs/namei.c:226
 vfs_mkdir+0x406/0x620 fs/namei.c:5276
 filename_mkdirat+0x285/0x510 fs/namei.c:5309
 __do_sys_mkdirat fs/namei.c:5330 [inline]
 __se_sys_mkdirat+0x35/0x150 fs/namei.c:5327
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f335ed9cf47
Code: 00 66 90 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 db f7 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 b8 02 01 00 00 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:00007f335fb98e18 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f335fb98ea0 RCX: 00007f335ed9cf47
RDX: 00000000000001ff RSI: 0000200000000280 RDI: 00000000ffffff9c
RBP: 00002000000006c0 R08: 0000200000000080 R09: 0000000000000000
R10: 00002000000006c0 R11: 0000000000000246 R12: 0000200000000280
R13: 00007f335fb98e60 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dbFindLeaf+0x519/0x520 fs/jfs/jfs_dmap.c:3070
Code: e9 4e ff ff ff e8 c7 8a 5e fe 48 c7 c7 a0 59 2c 8c 48 c7 c6 e0 56 2c 8c ba fe 0b 00 00 48 c7 c1 c0 64 2c 8c e8 a8 27 bf fd 90 <0f> 0b 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000f997618 EFLAGS: 00010246
RAX: 000000000000002b RBX: 00000000ffffffff RCX: f1ce9ed415c15400
RDX: ffffc9000f0aa000 RSI: 0000000000000dd0 RDI: 0000000000000dd1
RBP: 000000000a04ffff R08: ffffc9000f9973a7 R09: 1ffff92001f32e74
R10: dffffc0000000000 R11: fffff52001f32e75 R12: 0000000000000000
R13: 000000000000000d R14: 0000000000000010 R15: 0000000000000155
FS:  00007f335fb996c0(0000) GS:ffff88808c540000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1213b54000 CR3: 000000001d3b8000 CR4: 0000000000352ef0