ERROR: (device loop4): remounting filesystem as read-only
BUG at fs/jfs/jfs_dmap.c:3058 assert(n < 4)
------------[ cut here ]------------
kernel BUG at fs/jfs/jfs_dmap.c:3058!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 4279 Comm: syz.4.5 Not tainted 5.15.182-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:dbFindLeaf+0x517/0x520 fs/jfs/jfs_dmap.c:3058
Code: fe e9 51 ff ff ff e8 48 ed ac fe 48 c7 c7 80 f9 41 8a 48 c7 c6 00 f7 41 8a ba f2 0b 00 00 48 c7 c1 80 04 42 8a e8 19 de cb 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:ffffc900012eea30 EFLAGS: 00010246
RAX: 000000000000002b RBX: 00000000ffffffff RCX: 24c98c544f96b700
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000001 R08: dffffc0000000000 R09: ffffed10172067a8
R10: ffffed10172067a8 R11: 1ffff110172067a7 R12: 0000000000000000
R13: 00000000000000d0 R14: 00000000000000cd R15: 0000000000000155
FS:  00007fa94d7886c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000fffffa40 CR3: 000000001fd91000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 dbAllocDmapLev+0x61/0x3c0 fs/jfs/jfs_dmap.c:2044
 dbAllocCtl+0x148/0x9a0 fs/jfs/jfs_dmap.c:1900
 dbAllocAG+0xb9c/0xf10 fs/jfs/jfs_dmap.c:1549
 dbAlloc+0x5a3/0xb90 fs/jfs/jfs_dmap.c:892
 extBalloc fs/jfs/jfs_extent.c:523 [inline]
 extAlloc+0x4d2/0xf30 fs/jfs/jfs_extent.c:125
 jfs_get_block+0x343/0xab0 fs/jfs/inode.c:258
 nobh_write_begin+0x3d5/0xe80 fs/buffer.c:2650
 jfs_write_begin+0x3d/0x80 fs/jfs/inode.c:322
 generic_perform_write+0x2aa/0x530 mm/filemap.c:3785
 __generic_file_write_iter+0x25f/0x4e0 mm/filemap.c:3912
 generic_file_write_iter+0xa6/0x1b0 mm/filemap.c:3944
 __kernel_write+0x4f9/0x930 fs/read_write.c:539
 __dump_emit+0x243/0x360 fs/coredump.c:875
 dump_user_range+0x84/0x340 fs/coredump.c:949
 elf_core_dump+0x2ff7/0x3530 fs/binfmt_elf.c:2285
 do_coredump+0x139f/0x28f0 fs/coredump.c:826
 get_signal+0x40a/0x12c0 kernel/signal.c:2886
 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320
 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1504
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7fa94f920971
Code: 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 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:00000000fffffe10 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fa94fb47fa0 RCX: 00007fa94f920969
RDX: 0000000000000000 RSI: 00000000fffffe10 RDI: 0000000000000000
RBP: 00007fa94f9a2ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fa94fb47fa0 R15: 00007ffd48fe67b8
 </TASK>
Modules linked in:
---[ end trace a828b618349d810f ]---
RIP: 0010:dbFindLeaf+0x517/0x520 fs/jfs/jfs_dmap.c:3058
Code: fe e9 51 ff ff ff e8 48 ed ac fe 48 c7 c7 80 f9 41 8a 48 c7 c6 00 f7 41 8a ba f2 0b 00 00 48 c7 c1 80 04 42 8a e8 19 de cb 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:ffffc900012eea30 EFLAGS: 00010246
RAX: 000000000000002b RBX: 00000000ffffffff RCX: 24c98c544f96b700
RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000
RBP: 0000000000000001 R08: dffffc0000000000 R09: ffffed10172067a8
R10: ffffed10172067a8 R11: 1ffff110172067a7 R12: 0000000000000000
R13: 00000000000000d0 R14: 00000000000000cd R15: 0000000000000155
FS:  00007fa94d7886c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000fffffa40 CR3: 000000001fd91000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400