loop0: detected capacity change from 0 to 32768
BUG at fs/jfs/jfs_dmap.c:3051 assert(n < 4)
------------[ cut here ]------------
kernel BUG at fs/jfs/jfs_dmap.c:3051!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 4597 Comm: syz-executor.0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:dbFindLeaf+0x517/0x520 fs/jfs/jfs_dmap.c:3051
Code: fe e9 51 ff ff ff e8 38 b5 a9 fe 48 c7 c7 80 37 62 8a 48 c7 c6 00 35 62 8a ba eb 0b 00 00 48 c7 c1 80 42 62 8a e8 f9 3d e3 06 <0f> 0b 0f 1f 80 00 00 00 00 55 41 57 41 56 41 55 41 54 53 48 83 ec
RSP: 0018:ffffc900032ff348 EFLAGS: 00010246
RAX: 000000000000002b RBX: 00000000ffffffff RCX: 23fcca8c9003d600
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: ffff8880b9133d7f R09: 1ffff110172267af
R10: dffffc0000000000 R11: ffffed10172267b0 R12: 0000000000000000
R13: 0000000000000014 R14: 0000000000000011 R15: 0000000000000155
FS:  00007f709ecb96c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020ea0000 CR3: 000000001f973000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 dbAllocDmapLev+0x61/0x3c0 fs/jfs/jfs_dmap.c:2037
 dbAllocCtl+0x148/0x9b0 fs/jfs/jfs_dmap.c:1893
 dbAllocAG+0x1e7/0xfe0 fs/jfs/jfs_dmap.c:1421
 dbAlloc+0x5a6/0xba0 fs/jfs/jfs_dmap.c:877
 extBalloc fs/jfs/jfs_extent.c:523 [inline]
 extAlloc+0x4fc/0xf80 fs/jfs/jfs_extent.c:125
 jfs_get_block+0x355/0xad0 fs/jfs/inode.c:264
 nobh_write_begin+0x3d5/0xe80 fs/buffer.c:2650
 jfs_write_begin+0x3d/0x80 fs/jfs/inode.c:328
 generic_perform_write+0x2b6/0x550 mm/filemap.c:3785
 __generic_file_write_iter+0x25f/0x4e0 mm/filemap.c:3912
 generic_file_write_iter+0xa6/0x1b0 mm/filemap.c:3944
 do_iter_readv_writev+0x47e/0x5f0 fs/read_write.c:-1
 do_iter_write+0x205/0x7b0 fs/read_write.c:855
 vfs_writev fs/read_write.c:928 [inline]
 do_pwritev+0x240/0x3a0 fs/read_write.c:1025
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f709f9282b9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 d0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f709ecb90b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000148
RAX: ffffffffffffffda RBX: 00007f709fa66f80 RCX: 00007f709f9282b9
RDX: 0000000000000001 RSI: 0000000020000100 RDI: 0000000000000004
RBP: 00007f709f989498 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000005405 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f709fa66f80 R15: 00007ffc36b80468
 </TASK>
Modules linked in:
---[ end trace ecd51914ba37e878 ]---
RIP: 0010:dbFindLeaf+0x517/0x520 fs/jfs/jfs_dmap.c:3051
Code: fe e9 51 ff ff ff e8 38 b5 a9 fe 48 c7 c7 80 37 62 8a 48 c7 c6 00 35 62 8a ba eb 0b 00 00 48 c7 c1 80 42 62 8a e8 f9 3d e3 06 <0f> 0b 0f 1f 80 00 00 00 00 55 41 57 41 56 41 55 41 54 53 48 83 ec
RSP: 0018:ffffc900032ff348 EFLAGS: 00010246
RAX: 000000000000002b RBX: 00000000ffffffff RCX: 23fcca8c9003d600
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: ffff8880b9133d7f R09: 1ffff110172267af
R10: dffffc0000000000 R11: ffffed10172267b0 R12: 0000000000000000
R13: 0000000000000014 R14: 0000000000000011 R15: 0000000000000155
FS:  00007f709ecb96c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000563b12c30138 CR3: 000000001f973000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400