==================================================================
BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
BUG: KASAN: use-after-free in dbNextAG+0x14f/0x530 fs/jfs/jfs_dmap.c:622
Read of size 4 at addr ffff8881697d07d0 by task syz-executor.4/15509

CPU: 1 PID: 15509 Comm: syz-executor.4 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354
 kasan_report+0x8f/0xa0 mm/kasan/report.c:412
 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
 dbNextAG+0x14f/0x530 fs/jfs/jfs_dmap.c:622
 dbAlloc+0x44b/0xb00 fs/jfs/jfs_dmap.c:857
 dtSplitUp+0x365/0x4e70 fs/jfs/jfs_dtree.c:987
 dtInsert+0x7fd/0xa00 fs/jfs/jfs_dtree.c:876
 jfs_create.part.0+0x3c6/0x880 fs/jfs/namei.c:150
 jfs_create+0x3f/0x60 fs/jfs/namei.c:90
 lookup_open+0x893/0x1a20 fs/namei.c:3235
 do_last fs/namei.c:3327 [inline]
 path_openat+0x1094/0x2df0 fs/namei.c:3537
 do_filp_open+0x18c/0x3f0 fs/namei.c:3567
 do_sys_open+0x3b3/0x520 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7efc8a7cd5f9
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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007efc89140168 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007efc8a8edf80 RCX: 00007efc8a7cd5f9
RDX: 00000000000026e1 RSI: 00000000200002c0 RDI: ffffffffffffff9c
RBP: 00007efc8a8287b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffeda892ddf R14: 00007efc89140300 R15: 0000000000022000

The buggy address belongs to the page:
page:ffffea0005a5f400 count:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x57ff00000000000()
raw: 057ff00000000000 ffffea0005a5f408 ffffea0005a5f408 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881697d0680: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881697d0700: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881697d0780: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                                 ^
 ffff8881697d0800: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881697d0880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
ERROR: (device loop4): dbFindCtl: Corrupt dmapctl page