loop0: detected capacity change from 0 to 32768
------------[ cut here ]------------
UBSAN: shift-out-of-bounds in fs/jfs/jfs_dmap.c:1440:48
shift exponent -1 is negative
CPU: 0 UID: 0 PID: 6733 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack+0x30/0x40 lib/dump_stack.c:94
 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
 dump_stack+0x1c/0x28 lib/dump_stack.c:129
 ubsan_epilogue+0x14/0x48 lib/ubsan.c:233
 __ubsan_handle_shift_out_of_bounds+0x2b0/0x34c lib/ubsan.c:494
 dbAllocAG+0xd9c/0xdc0 fs/jfs/jfs_dmap.c:1440
 dbAlloc+0x428/0x9dc fs/jfs/jfs_dmap.c:877
 extBalloc fs/jfs/jfs_extent.c:336 [inline]
 extAlloc+0x42c/0xdc8 fs/jfs/jfs_extent.c:127
 jfs_get_block+0x2bc/0x8b8 fs/jfs/inode.c:248
 __block_write_begin_int+0x53c/0x15e8 fs/buffer.c:2145
 block_write_begin+0xa0/0x128 fs/buffer.c:2256
 jfs_write_begin+0x44/0x88 fs/jfs/inode.c:300
 generic_perform_write+0x244/0x7bc mm/filemap.c:4175
 __generic_file_write_iter+0xfc/0x204 mm/filemap.c:4292
 generic_file_write_iter+0x10c/0x47c mm/filemap.c:4318
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x540/0xa3c fs/read_write.c:686
 ksys_write+0x120/0x210 fs/read_write.c:738
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:746
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x254 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x5c/0x254 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:763
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
---[ end trace ]---