loop0: detected capacity change from 32768 to 32767
BUG at fs/jfs/jfs_dmap.c:2983 assert(n < 4)
------------[ cut here ]------------
kernel BUG at fs/jfs/jfs_dmap.c:2983!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 0 UID: 0 PID: 5319 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:dbFindLeaf+0x51d/0x520 fs/jfs/jfs_dmap.c:2983
Code: e9 4c ff ff ff e8 53 79 7a fe 48 c7 c7 c0 7d a4 8b 48 c7 c6 00 7b a4 8b ba a7 0b 00 00 48 c7 c1 80 88 a4 8b e8 e4 f4 e1 fd 90 <0f> 0b 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57
RSP: 0018:ffffc9000fd47148 EFLAGS: 00010246
RAX: 000000000000002b RBX: 00000000ffffffff RCX: 5ce41214e07fa600
RDX: ffffc9000e52b000 RSI: 0000000000000e06 RDI: 0000000000000e07
RBP: 000000000a04ffff R08: ffffc9000fd46e67 R09: 1ffff92001fa8dcc
R10: dffffc0000000000 R11: fffff52001fa8dcd R12: 0000000000000000
R13: 0000000000000010 R14: 000000000000000d R15: 0000000000000155
FS:  00007f6a59df86c0(0000) GS:ffff88808d732000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556e0847c8 CR3: 0000000011d0d000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 dbAllocDmapLev+0x60/0x3c0 fs/jfs/jfs_dmap.c:1969
 dbAllocCtl+0x14a/0x9c0 fs/jfs/jfs_dmap.c:1825
 dbAllocAG+0x1e6/0xff0 fs/jfs/jfs_dmap.c:1353
 dbAlloc+0x5a8/0xba0 fs/jfs/jfs_dmap.c:877
 dtSplitUp fs/jfs/jfs_dtree.c:982 [inline]
 dtInsert+0xad5/0x5f40 fs/jfs/jfs_dtree.c:871
 jfs_create+0x6c8/0xa80 fs/jfs/namei.c:137
 lookup_open fs/namei.c:3796 [inline]
 open_last_lookups fs/namei.c:3895 [inline]
 path_openat+0x14f4/0x3830 fs/namei.c:4131
 do_filp_open+0x1fa/0x410 fs/namei.c:4161
 do_sys_openat2+0x121/0x1c0 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1463
 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: 0033:0x7f6a58f8efc9
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:00007f6a59df8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f6a591e6090 RCX: 00007f6a58f8efc9
RDX: 000000000000275a RSI: 0000200000000200 RDI: ffffffffffffff9c
RBP: 00007f6a59011f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6a591e6128 R14: 00007f6a591e6090 R15: 00007ffe660cae88
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dbFindLeaf+0x51d/0x520 fs/jfs/jfs_dmap.c:2983
Code: e9 4c ff ff ff e8 53 79 7a fe 48 c7 c7 c0 7d a4 8b 48 c7 c6 00 7b a4 8b ba a7 0b 00 00 48 c7 c1 80 88 a4 8b e8 e4 f4 e1 fd 90 <0f> 0b 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57
RSP: 0018:ffffc9000fd47148 EFLAGS: 00010246
RAX: 000000000000002b RBX: 00000000ffffffff RCX: 5ce41214e07fa600
RDX: ffffc9000e52b000 RSI: 0000000000000e06 RDI: 0000000000000e07
RBP: 000000000a04ffff R08: ffffc9000fd46e67 R09: 1ffff92001fa8dcc
R10: dffffc0000000000 R11: fffff52001fa8dcd R12: 0000000000000000
R13: 0000000000000010 R14: 000000000000000d R15: 0000000000000155
FS:  00007f6a59df86c0(0000) GS:ffff88808d732000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6a59db5fc8 CR3: 0000000011d0d000 CR4: 0000000000352ef0