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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 ffff8881b8cbac80 by task syz-executor408/8078

CPU: 1 PID: 8078 Comm: syz-executor408 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
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
 diAlloc+0x7ea/0x1440 fs/jfs/jfs_imap.c:1380
 ialloc+0x8c/0x970 fs/jfs/jfs_inode.c:69
 jfs_mkdir.part.0+0x131/0x870 fs/jfs/namei.c:237
 jfs_mkdir+0x3f/0x60 fs/jfs/namei.c:222
 vfs_mkdir+0x508/0x7a0 fs/namei.c:3819
 do_mkdirat+0x262/0x2d0 fs/namei.c:3842
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7faa817d7397
Code: ff ff ff ff c3 66 0f 1f 44 00 00 48 c7 c0 c0 ff ff ff 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 b8 53 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffedfbfe818 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007ffedfbfe8c0 RCX: 00007faa817d7397
RDX: 0000000000000000 RSI: 00000000000001ff RDI: 00000000200001c0
RBP: 00000000ffffffff R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00000000ffffffff R14: 00000000200001c0 R15: 0000000000000000

The buggy address belongs to the page:
page:ffffea0006e32e80 count:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x57ff00000000000()
raw: 057ff00000000000 ffffea0006e32e88 ffffea0006e32e88 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881b8cbab80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881b8cbac00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881b8cbac80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff8881b8cbad00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881b8cbad80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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