loop0: detected capacity change from 0 to 32768
------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:2902:18
index -3 is out of range for type 's8[1365]' (aka 'signed char[1365]')
CPU: 0 UID: 0 PID: 5326 Comm: syz.0.0 Not tainted 6.12.0-rc6-syzkaller-00318-ga9cda7c0ffed #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 ubsan_epilogue lib/ubsan.c:231 [inline]
 __ubsan_handle_out_of_bounds+0x121/0x150 lib/ubsan.c:429
 dbAdjTree+0x377/0x520 fs/jfs/jfs_dmap.c:2902
 dbAllocBits+0x4ea/0x990 fs/jfs/jfs_dmap.c:2193
 dbAllocDmap+0x6d/0x150 fs/jfs/jfs_dmap.c:2034
 dbAlloc+0x509/0xca0 fs/jfs/jfs_dmap.c:816
 extBalloc fs/jfs/jfs_extent.c:326 [inline]
 extAlloc+0x4f8/0x1010 fs/jfs/jfs_extent.c:122
 jfs_get_block+0x41b/0xe60 fs/jfs/inode.c:248
 __block_write_begin_int+0x50c/0x1a70 fs/buffer.c:2121
 block_write_begin+0x8f/0x120 fs/buffer.c:2231
 jfs_write_begin+0x31/0x70 fs/jfs/inode.c:299
 generic_perform_write+0x344/0x6d0 mm/filemap.c:4054
 generic_file_write_iter+0xae/0x310 mm/filemap.c:4181
 new_sync_write fs/read_write.c:590 [inline]
 vfs_write+0xaeb/0xd30 fs/read_write.c:683
 ksys_write+0x183/0x2b0 fs/read_write.c:736
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1a6837e719
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:00007f1a69164038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f1a68535f80 RCX: 00007f1a6837e719
RDX: 000000000208e24b RSI: 0000000020000240 RDI: 0000000000000004
RBP: 00007f1a683f139e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f1a68535f80 R15: 00007fff2c667bd8
 </TASK>
---[ end trace ]---