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BUG: KASAN: slab-out-of-bounds in find_first_zero_bit+0xa8/0xb0 lib/find_bit.c:125
Read of size 8 at addr ffff888087051380 by task syz-executor.4/9779

CPU: 1 PID: 9779 Comm: syz-executor.4 Not tainted 4.19.146-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x22c/0x33e lib/dump_stack.c:118
 print_address_description.cold+0x56/0x25c mm/kasan/report.c:256
 kasan_report_error.cold+0x66/0xb9 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433
 find_first_zero_bit+0xa8/0xb0 lib/find_bit.c:125
 bfs_create+0xf3/0x580 fs/bfs/dir.c:91
 lookup_open+0x86c/0x19c0 fs/namei.c:3235
 do_last fs/namei.c:3327 [inline]
 path_openat+0x10d6/0x2e90 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+0xf9/0x670 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45d5f9
Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f410e675c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000000225c0 RCX: 000000000045d5f9
RDX: 00000000001015c2 RSI: 0000000020000440 RDI: ffffffffffffff9c
RBP: 000000000118d028 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec
R13: 00007ffee9b6973f R14: 00007f410e6769c0 R15: 000000000118cfec

Allocated by task 9765:
 __do_kmalloc mm/slab.c:3727 [inline]
 __kmalloc+0x15a/0x4f0 mm/slab.c:3736
 kmalloc include/linux/slab.h:520 [inline]
 kzalloc include/linux/slab.h:709 [inline]
 bfs_fill_super+0x447/0xfa0 fs/bfs/inode.c:363
 mount_bdev+0x2fc/0x3b0 fs/super.c:1158
 mount_fs+0xa3/0x318 fs/super.c:1261
 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2469 [inline]
 do_mount+0x51c/0x2f10 fs/namespace.c:2799
 ksys_mount+0xcf/0x130 fs/namespace.c:3015
 __do_sys_mount fs/namespace.c:3029 [inline]
 __se_sys_mount fs/namespace.c:3026 [inline]
 __x64_sys_mount+0xba/0x150 fs/namespace.c:3026
 do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 3720:
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcc/0x250 mm/slab.c:3822
 security_context_to_sid_core+0x2ed/0x610 security/selinux/ss/services.c:1504
 security_context_to_sid+0x35/0x40 security/selinux/ss/services.c:1525
 selinux_inode_setsecurity+0x197/0x3d0 security/selinux/hooks.c:3501
 selinux_inode_notifysecctx+0x2b/0x60 security/selinux/hooks.c:6667
 security_inode_notifysecctx+0x50/0xb0 security/security.c:1343
 kernfs_refresh_inode+0x328/0x4b0 fs/kernfs/inode.c:195
 kernfs_iop_getattr+0x90/0xd0 fs/kernfs/inode.c:210
 vfs_getattr_nosec+0xff/0x160 fs/stat.c:79
 vfs_getattr fs/stat.c:116 [inline]
 vfs_statx+0x15a/0x210 fs/stat.c:189
 vfs_lstat include/linux/fs.h:3138 [inline]
 __do_sys_newlstat fs/stat.c:350 [inline]
 __se_sys_newlstat+0x96/0x120 fs/stat.c:344
 do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff888087051380
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
 32-byte region [ffff888087051380, ffff8880870513a0)
The buggy address belongs to the page:
page:ffffea00021c1440 count:1 mapcount:0 mapping:ffff88812c3f61c0 index:0xffff888087051fc1
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffffea00027b9488 ffffea00023d2948 ffff88812c3f61c0
raw: ffff888087051fc1 ffff888087051000 000000010000003e 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888087051280: fb fb fb fb fc fc fc fc 00 00 00 fc fc fc fc fc
 ffff888087051300: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff888087051380: 07 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc
                   ^
 ffff888087051400: fb fb fb fb fc fc fc fc 00 00 fc fc fc fc fc fc
 ffff888087051480: 00 00 fc fc fc fc fc fc fb fb fb fb fc fc fc fc
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