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BUG: KASAN: slab-use-after-free in kernfs_test_super+0x7c/0x100 fs/kernfs/mount.c:286
Read of size 8 at addr ffff88807afe4b88 by task syz-executor.5/21188

CPU: 1 PID: 21188 Comm: syz-executor.5 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+0x1e7/0x2d0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0x163/0x540 mm/kasan/report.c:475
 kasan_report+0x175/0x1b0 mm/kasan/report.c:588
 kernfs_test_super+0x7c/0x100 fs/kernfs/mount.c:286
 sget_fc+0x145/0x750 fs/super.c:778
 kernfs_get_tree+0x1a8/0x780 fs/kernfs/mount.c:337
 sysfs_get_tree+0x45/0x120 fs/sysfs/mount.c:31
 vfs_get_tree+0x8c/0x280 fs/super.c:1711
 do_new_mount+0x28f/0xae0 fs/namespace.c:3335
 do_mount fs/namespace.c:3675 [inline]
 __do_sys_mount fs/namespace.c:3884 [inline]
 __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3861
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f932a47cae9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 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 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f932b1c40c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f932a59bf80 RCX: 00007f932a47cae9
RDX: 0000000020000380 RSI: 0000000020000080 RDI: 0000000000000000
RBP: 00007f932a4c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f932a59bf80 R15: 00007ffc1f24fe18
 </TASK>

Allocated by task 21186:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4f/0x70 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:383
 kmalloc include/linux/slab.h:582 [inline]
 kzalloc include/linux/slab.h:703 [inline]
 kernfs_get_tree+0x76/0x780 fs/kernfs/mount.c:328
 sysfs_get_tree+0x45/0x120 fs/sysfs/mount.c:31
 vfs_get_tree+0x8c/0x280 fs/super.c:1711
 do_new_mount+0x28f/0xae0 fs/namespace.c:3335
 do_mount fs/namespace.c:3675 [inline]
 __do_sys_mount fs/namespace.c:3884 [inline]
 __se_sys_mount+0x2d9/0x3c0 fs/namespace.c:3861
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 7159:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4f/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522
 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:162 [inline]
 slab_free_hook mm/slub.c:1792 [inline]
 slab_free_freelist_hook mm/slub.c:1818 [inline]
 slab_free mm/slub.c:3801 [inline]
 __kmem_cache_free+0x25f/0x3b0 mm/slub.c:3814
 sysfs_kill_sb+0x22/0x40 fs/sysfs/mount.c:86
 deactivate_locked_super+0xa5/0x200 fs/super.c:454
 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1254
 task_work_run+0x24a/0x300 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xd9/0x100 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x64/0x280 kernel/entry/common.c:296
 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

The buggy address belongs to the object at ffff88807afe4b80
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 8 bytes inside of
 freed 64-byte region [ffff88807afe4b80, ffff88807afe4bc0)

The buggy address belongs to the physical page:
page:ffffea0001ebf900 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7afe4
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000200 ffff888012841640 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000200020 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 7579, tgid 7579 (udevd), ts 764672736111, free_ts 764560782881
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1570
 prep_new_page mm/page_alloc.c:1577 [inline]
 get_page_from_freelist+0x31e8/0x3370 mm/page_alloc.c:3221
 __alloc_pages+0x255/0x670 mm/page_alloc.c:4477
 alloc_slab_page+0x6a/0x160 mm/slub.c:1862
 allocate_slab mm/slub.c:2009 [inline]
 new_slab+0x84/0x2f0 mm/slub.c:2062
 ___slab_alloc+0xade/0x1100 mm/slub.c:3215
 __slab_alloc mm/slub.c:3314 [inline]
 __slab_alloc_node mm/slub.c:3367 [inline]
 slab_alloc_node mm/slub.c:3460 [inline]
 __kmem_cache_alloc_node+0x1af/0x270 mm/slub.c:3509
 __do_kmalloc_node mm/slab_common.c:984 [inline]
 __kmalloc+0xa8/0x230 mm/slab_common.c:998
 kmalloc include/linux/slab.h:586 [inline]
 kzalloc include/linux/slab.h:703 [inline]
 tomoyo_encode2 security/tomoyo/realpath.c:45 [inline]
 tomoyo_encode+0x26f/0x530 security/tomoyo/realpath.c:80
 tomoyo_realpath_from_path+0x598/0x5e0 security/tomoyo/realpath.c:283
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_check_open_permission+0x254/0x4e0 security/tomoyo/file.c:771
 security_file_open+0x63/0xa0 security/security.c:2811
 do_dentry_open+0x325/0x1430 fs/open.c:916
 do_open fs/namei.c:3639 [inline]
 path_openat+0x27bb/0x3180 fs/namei.c:3796
 do_filp_open+0x234/0x490 fs/namei.c:3823
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1422
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+0x903/0xa30 mm/page_alloc.c:2348
 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2443
 tlb_batch_list_free mm/mmu_gather.c:113 [inline]
 tlb_finish_mmu+0x11f/0x1f0 mm/mmu_gather.c:394
 exit_mmap+0x3e2/0xad0 mm/mmap.c:3215
 __mmput+0x115/0x3c0 kernel/fork.c:1356
 exit_mm+0x21f/0x300 kernel/exit.c:567
 do_exit+0x612/0x2290 kernel/exit.c:861
 do_group_exit+0x206/0x2c0 kernel/exit.c:1024
 __do_sys_exit_group kernel/exit.c:1035 [inline]
 __se_sys_exit_group kernel/exit.c:1033 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
 ffff88807afe4a80: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88807afe4b00: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff88807afe4b80: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                      ^
 ffff88807afe4c00: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
 ffff88807afe4c80: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
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