syzbot

loop0: detected capacity change from 0 to 32768
BUG at fs/jfs/jfs_dmap.c:3051 assert(n < 4)
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kernel BUG at fs/jfs/jfs_dmap.c:3051!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 4308 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:dbFindLeaf+0x517/0x520 fs/jfs/jfs_dmap.c:3051
Code: fe e9 51 ff ff ff e8 38 bc a9 fe 48 c7 c7 00 2d 62 8a 48 c7 c6 80 2a 62 8a ba eb 0b 00 00 48 c7 c1 00 38 62 8a e8 59 b9 e2 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:ffffc90002fefac0 EFLAGS: 00010246
RAX: 000000000000002b RBX: 0000000000000000 RCX: 714d659229908b00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: ffff8880b9033d7f R09: 1ffff110172067af
R10: dffffc0000000000 R11: ffffed10172067b0 R12: 000000000000000a
R13: 0000000000000008 R14: 0000000000000005 R15: 0000000000000155
FS:  000055557b036500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8259865000 CR3: 000000002c6be000 CR4: 00000000003506f0
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+0xc23/0xfe0 fs/jfs/jfs_dmap.c:1540
 dbDiscardAG+0x2c5/0x8e0 fs/jfs/jfs_dmap.c:1676
 jfs_ioc_trim+0x41e/0x680 fs/jfs/jfs_discard.c:106
 jfs_ioctl+0x2b6/0x3c0 fs/jfs/ioctl.c:132
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 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: 0033:0x7f70d7c58dd9
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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffda599bd88 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f70d7ed1fa0 RCX: 00007f70d7c58dd9
RDX: 0000200000000040 RSI: 00000000c0185879 RDI: 0000000000000004
RBP: 00007f70d7ceed69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f70d7ed1fac R14: 00007f70d7ed1fa0 R15: 00007f70d7ed1fa0
 </TASK>
Modules linked in:
---[ end trace 71b2921baf624fc0 ]---
RIP: 0010:dbFindLeaf+0x517/0x520 fs/jfs/jfs_dmap.c:3051
Code: fe e9 51 ff ff ff e8 38 bc a9 fe 48 c7 c7 00 2d 62 8a 48 c7 c6 80 2a 62 8a ba eb 0b 00 00 48 c7 c1 00 38 62 8a e8 59 b9 e2 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:ffffc90002fefac0 EFLAGS: 00010246
RAX: 000000000000002b RBX: 0000000000000000 RCX: 714d659229908b00
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: ffff8880b9033d7f R09: 1ffff110172067af
R10: dffffc0000000000 R11: ffffed10172067b0 R12: 000000000000000a
R13: 0000000000000008 R14: 0000000000000005 R15: 0000000000000155
FS:  000055557b036500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc91daabbc CR3: 000000002c6be000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400