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BUG: KASAN: use-after-free in btrfs_test_super+0x9b/0xa0 fs/btrfs/super.c:1348
Read of size 8 at addr ffff888021bf1110 by task syz-executor.4/9442

CPU: 1 PID: 9442 Comm: syz-executor.4 Not tainted 6.5.0-syzkaller-01207-g1c59d383390f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0xc4/0x620 mm/kasan/report.c:475
 kasan_report+0xda/0x110 mm/kasan/report.c:588
 btrfs_test_super+0x9b/0xa0 fs/btrfs/super.c:1348
 sget+0x3de/0x610 fs/super.c:861
 btrfs_mount_root+0x692/0xdd0 fs/btrfs/super.c:1508
 legacy_get_tree+0x109/0x220 fs/fs_context.c:638
 vfs_get_tree+0x8c/0x370 fs/super.c:1711
 fc_mount fs/namespace.c:1112 [inline]
 vfs_kern_mount.part.0+0xcb/0x170 fs/namespace.c:1142
 vfs_kern_mount+0x3f/0x60 fs/namespace.c:1129
 btrfs_mount+0x292/0xb10 fs/btrfs/super.c:1585
 legacy_get_tree+0x109/0x220 fs/fs_context.c:638
 vfs_get_tree+0x8c/0x370 fs/super.c:1711
 do_new_mount fs/namespace.c:3335 [inline]
 path_mount+0x1492/0x1ed0 fs/namespace.c:3662
 do_mount fs/namespace.c:3675 [inline]
 __do_sys_mount fs/namespace.c:3884 [inline]
 __se_sys_mount fs/namespace.c:3861 [inline]
 __x64_sys_mount+0x293/0x310 fs/namespace.c:3861
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fca7ee7e1ea
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 09 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fca7fbd5ee8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fca7fbd5f80 RCX: 00007fca7ee7e1ea
RDX: 00000000200055c0 RSI: 0000000020005600 RDI: 00007fca7fbd5f40
RBP: 00000000200055c0 R08: 00007fca7fbd5f80 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000020005600
R13: 00007fca7fbd5f40 R14: 00000000000055a8 R15: 0000000020005640
 </TASK>

The buggy address belongs to the physical page:
page:ffffea000086fc40 refcount:0 mapcount:0 mapping:0000000000000000 index:0x4 pfn:0x21bf1
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000000 0000000000000000 ffffffff00860201 0000000000000000
raw: 0000000000000004 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x152dc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_ZERO), pid 9431, tgid 9428 (syz-executor.3), ts 450492491341, free_ts 452001987285
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x2d2/0x350 mm/page_alloc.c:1570
 prep_new_page mm/page_alloc.c:1577 [inline]
 get_page_from_freelist+0x10a9/0x31e0 mm/page_alloc.c:3221
 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4477
 __alloc_pages_node include/linux/gfp.h:237 [inline]
 alloc_pages_node include/linux/gfp.h:260 [inline]
 __kmalloc_large_node+0x87/0x1c0 mm/slab_common.c:1126
 __do_kmalloc_node mm/slab_common.c:973 [inline]
 __kmalloc_node.cold+0x5/0xdd mm/slab_common.c:992
 kmalloc_node include/linux/slab.h:602 [inline]
 kvmalloc_node+0x6f/0x1a0 mm/util.c:604
 kvmalloc include/linux/slab.h:720 [inline]
 kvzalloc include/linux/slab.h:728 [inline]
 btrfs_mount_root+0x130/0xdd0 fs/btrfs/super.c:1466
 legacy_get_tree+0x109/0x220 fs/fs_context.c:638
 vfs_get_tree+0x8c/0x370 fs/super.c:1711
 fc_mount fs/namespace.c:1112 [inline]
 vfs_kern_mount.part.0+0xcb/0x170 fs/namespace.c:1142
 vfs_kern_mount+0x3f/0x60 fs/namespace.c:1129
 btrfs_mount+0x292/0xb10 fs/btrfs/super.c:1585
 legacy_get_tree+0x109/0x220 fs/fs_context.c:638
 vfs_get_tree+0x8c/0x370 fs/super.c:1711
 do_new_mount fs/namespace.c:3335 [inline]
 path_mount+0x1492/0x1ed0 fs/namespace.c:3662
 do_mount fs/namespace.c:3675 [inline]
 __do_sys_mount fs/namespace.c:3884 [inline]
 __se_sys_mount fs/namespace.c:3861 [inline]
 __x64_sys_mount+0x293/0x310 fs/namespace.c:3861
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1161 [inline]
 free_unref_page_prepare+0x508/0xb90 mm/page_alloc.c:2348
 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2443
 kvfree+0x47/0x50 mm/util.c:650
 deactivate_locked_super+0xa0/0x2d0 fs/super.c:454
 deactivate_super+0xde/0x100 fs/super.c:504
 cleanup_mnt+0x222/0x3d0 fs/namespace.c:1254
 task_work_run+0x14d/0x240 kernel/task_work.c:179
 ptrace_notify+0x10c/0x130 kernel/signal.c:2376
 ptrace_report_syscall include/linux/ptrace.h:411 [inline]
 ptrace_report_syscall_exit include/linux/ptrace.h:473 [inline]
 syscall_exit_work kernel/entry/common.c:251 [inline]
 syscall_exit_to_user_mode_prepare+0x120/0x220 kernel/entry/common.c:278
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0xd/0x60 kernel/entry/common.c:296
 do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
 ffff888021bf1000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888021bf1080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888021bf1100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                         ^
 ffff888021bf1180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff888021bf1200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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