loop0: detected capacity change from 0 to 32768
find_entry called with index = 0
read_mapping_page failed!
ERROR: (device loop0): txCommit: 
loop0: detected capacity change from 32768 to 4098
------------[ cut here ]------------
UBSAN: array-index-out-of-bounds in fs/jfs/jfs_dmap.c:2780:24
index 4294967295 is out of range for type 's8[1365]' (aka 'signed char[1365]')
CPU: 0 UID: 0 PID: 5346 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
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_lvl+0xe8/0x150 lib/dump_stack.c:120
 ubsan_epilogue+0xa/0x40 lib/ubsan.c:233
 __ubsan_handle_out_of_bounds+0xe9/0xf0 lib/ubsan.c:455
 dbJoin+0x29f/0x300 fs/jfs/jfs_dmap.c:2780
 dbFreeBits+0x4e1/0xdb0 fs/jfs/jfs_dmap.c:2340
 dbFreeDmap fs/jfs/jfs_dmap.c:2089 [inline]
 dbFree+0x336/0x650 fs/jfs/jfs_dmap.c:398
 txFreeMap+0x9e6/0xde0 fs/jfs/jfs_txnmgr.c:2516
 xtTruncate+0xcea/0x2e70 fs/jfs/jfs_xtree.c:2481
 jfs_free_zero_link+0x33a/0x4a0 fs/jfs/namei.c:759
 jfs_evict_inode+0x363/0x440 fs/jfs/inode.c:159
 evict+0x5f4/0xae0 fs/inode.c:837
 __dentry_kill+0x209/0x660 fs/dcache.c:670
 shrink_kill+0xa9/0x2c0 fs/dcache.c:1137
 shrink_dentry_list+0x2e0/0x5e0 fs/dcache.c:1164
 shrink_dcache_tree+0xca/0x2e0 fs/dcache.c:-1
 do_one_tree+0x28/0xe0 fs/dcache.c:1644
 shrink_dcache_for_umount+0xa0/0x170 fs/dcache.c:1661
 generic_shutdown_super+0x67/0x2c0 fs/super.c:621
 kill_block_super+0x44/0x90 fs/super.c:1722
 deactivate_locked_super+0xbc/0x130 fs/super.c:474
 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
 task_work_run+0x1d4/0x260 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
 exit_to_user_mode_loop+0xef/0x4e0 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x2c1/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe06398f7c9
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:00007fe0647aa038 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fe063be5fa0 RCX: 00007fe06398f7c9
RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000000000000003
RBP: 00007fe063a13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe063be6038 R14: 00007fe063be5fa0 R15: 00007ffc2f553258
 </TASK>
---[ end trace ]---