loop0: detected capacity change from 0 to 32768
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: 5328 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 83 4e 7a fe 48 c7 c7 40 7f a4 8b 48 c7 c6 80 7c a4 8b ba a7 0b 00 00 48 c7 c1 00 8a a4 8b e8 e4 cc 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:ffffc9000d48f628 EFLAGS: 00010246
RAX: 000000000000002b RBX: 00000000ffffffff RCX: 0067af44d55d5300
RDX: ffffc9000e0ea000 RSI: 0000000000000d34 RDI: 0000000000000d35
RBP: 0000000008ffff09 R08: ffffc9000d48f347 R09: 1ffff92001a91e68
R10: dffffc0000000000 R11: fffff52001a91e69 R12: 0000000000000000
R13: 000000000000000c R14: 0000000000000009 R15: 0000000000000155
FS:  00007f2f810eb6c0(0000) GS:ffff88808d72f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc80d39e000 CR3: 0000000041698000 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
 diNewIAG fs/jfs/jfs_imap.c:2510 [inline]
 diAllocExt fs/jfs/jfs_imap.c:1905 [inline]
 diAllocAG+0xd45/0x1df0 fs/jfs/jfs_imap.c:1669
 diAlloc+0x1d5/0x1680 fs/jfs/jfs_imap.c:1590
 ialloc+0x8c/0x8f0 fs/jfs/jfs_inode.c:56
 jfs_mkdir+0x193/0xa70 fs/jfs/namei.c:225
 vfs_mkdir+0x306/0x510 fs/namei.c:4453
 do_mkdirat+0x247/0x590 fs/namei.c:4486
 __do_sys_mkdir fs/namei.c:4508 [inline]
 __se_sys_mkdir fs/namei.c:4506 [inline]
 __x64_sys_mkdir+0x6c/0x80 fs/namei.c:4506
 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: 0033:0x7f2f8018f749
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:00007f2f810eb038 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f2f803e5fa0 RCX: 00007f2f8018f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000300
RBP: 00007f2f80213f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2f803e6038 R14: 00007f2f803e5fa0 R15: 00007fff15af7578
 </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 83 4e 7a fe 48 c7 c7 40 7f a4 8b 48 c7 c6 80 7c a4 8b ba a7 0b 00 00 48 c7 c1 00 8a a4 8b e8 e4 cc 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:ffffc9000d48f628 EFLAGS: 00010246
RAX: 000000000000002b RBX: 00000000ffffffff RCX: 0067af44d55d5300
RDX: ffffc9000e0ea000 RSI: 0000000000000d34 RDI: 0000000000000d35
RBP: 0000000008ffff09 R08: ffffc9000d48f347 R09: 1ffff92001a91e68
R10: dffffc0000000000 R11: fffff52001a91e69 R12: 0000000000000000
R13: 000000000000000c R14: 0000000000000009 R15: 0000000000000155
FS:  00007f2f810eb6c0(0000) GS:ffff88808d72f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2f801ee470 CR3: 0000000041698000 CR4: 0000000000352ef0