BTRFS info (device loop2): disk space caching is enabled
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BTRFS info (device loop2): has skinny extents
BUG: KASAN: use-after-free in btrfs_printk+0x34f/0x3d0 fs/btrfs/super.c:215
Read of size 8 at addr ffff8880af10da60 by task systemd-udevd/8148

CPU: 1 PID: 8148 Comm: systemd-udevd Not tainted 4.19.157-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+0x1fc/0x2fe lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1c7 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_load8_noabort+0x88/0x90 mm/kasan/report.c:433
 btrfs_printk+0x34f/0x3d0 fs/btrfs/super.c:215
 device_list_add.cold+0x1a0/0x376 fs/btrfs/volumes.c:860
 btrfs_scan_one_device+0x33f/0xd00 fs/btrfs/volumes.c:1275
 btrfs_control_ioctl+0x16b/0x2a0 fs/btrfs/super.c:2274
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0xcdb/0x12e0 fs/ioctl.c:688
 ksys_ioctl+0x9b/0xc0 fs/ioctl.c:705
 __do_sys_ioctl fs/ioctl.c:712 [inline]
 __se_sys_ioctl fs/ioctl.c:710 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:710
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f4a15b0a017
Code: 00 00 00 48 8b 05 81 7e 2b 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 51 7e 2b 00 f7 d8 64 89 01 48
RSP: 002b:00007ffc91e5fae8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4a15b0a017
RDX: 00007ffc91e5fb00 RSI: 0000000090009427 RDI: 000000000000000f
RBP: 00007ffc91e5fb00 R08: 0000000000000000 R09: 0000000000000048
R10: 0000000000000001 R11: 0000000000000246 R12: 000000000000000f
R13: 0000000000000000 R14: 0000555c56597de0 R15: 0000555c56582c00

Allocated by task 8194:
 __do_kmalloc_node mm/slab.c:3689 [inline]
 __kmalloc_node+0x4c/0x70 mm/slab.c:3696
 kmalloc_node include/linux/slab.h:557 [inline]
 kvmalloc_node+0xb4/0xf0 mm/util.c:423
 kvmalloc include/linux/mm.h:577 [inline]
 kvzalloc include/linux/mm.h:585 [inline]
 btrfs_mount_root+0x13f/0x1830 fs/btrfs/super.c:1556
 mount_fs+0xa3/0x30c fs/super.c:1261
 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
 vfs_kern_mount+0x3c/0x60 fs/namespace.c:951
 btrfs_mount+0x23a/0xa93 fs/btrfs/super.c:1681
 mount_fs+0xa3/0x30c 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+0x113c/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+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 8194:
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcc/0x210 mm/slab.c:3822
 kvfree+0x59/0x60 mm/util.c:452
 deactivate_locked_super+0x94/0x160 fs/super.c:329
 btrfs_mount_root+0x10a0/0x1830 fs/btrfs/super.c:1623
 mount_fs+0xa3/0x30c fs/super.c:1261
 vfs_kern_mount.part.0+0x68/0x470 fs/namespace.c:961
 vfs_kern_mount+0x3c/0x60 fs/namespace.c:951
 btrfs_mount+0x23a/0xa93 fs/btrfs/super.c:1681
 mount_fs+0xa3/0x30c 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+0x113c/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+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8880af10d440
 which belongs to the cache kmalloc-8192 of size 8192
The buggy address is located 1568 bytes inside of
 8192-byte region [ffff8880af10d440, ffff8880af10f440)
The buggy address belongs to the page:
page:ffffea0002bc4300 count:1 mapcount:0 mapping:ffff88813bff2080 index:0x0 compound_mapcount: 0
flags: 0xfff00000008100(slab|head)
raw: 00fff00000008100 ffffea0002bdc208 ffffea0002bdaa08 ffff88813bff2080
raw: 0000000000000000 ffff8880af10d440 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880af10d900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880af10d980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880af10da00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff8880af10da80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880af10db00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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