==================================================================
BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/rtmutex_api.c:561 [inline]
BUG: KASAN: slab-use-after-free in mutex_lock_interruptible_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:594
Read of size 1 at addr ffff888069bd2128 by task jffs2_gcd_mtd0/6397

CPU: 0 UID: 0 PID: 6397 Comm: jffs2_gcd_mtd0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 __kasan_check_byte+0x2a/0x40 mm/kasan/common.c:585
 kasan_check_byte include/linux/kasan.h:402 [inline]
 lock_acquire+0x7d/0x350 kernel/locking/lockdep.c:5916
 __mutex_lock_common kernel/locking/rtmutex_api.c:561 [inline]
 mutex_lock_interruptible_nested+0x5a/0x1d0 kernel/locking/rtmutex_api.c:594
 jffs2_garbage_collect_pass+0xb0/0x2170 fs/jffs2/gc.c:134
 jffs2_garbage_collect_thread+0x634/0x6c0 fs/jffs2/background.c:155
 kthread+0x38b/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 6374:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:426
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x3d5/0x680 mm/slub.c:5563
 _kmalloc_noprof include/linux/slab.h:991 [inline]
 _kzalloc_noprof include/linux/slab.h:1312 [inline]
 jffs2_init_fs_context+0x4f/0xc0 fs/jffs2/super.c:314
 alloc_fs_context+0x9a3/0xd00 fs/fs_context.c:295
 do_new_mount+0x177/0xb00 fs/namespace.c:3954
 do_mount fs/namespace.c:4338 [inline]
 __do_sys_mount fs/namespace.c:4556 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4533
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5584:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:264 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:296
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2748 [inline]
 slab_free mm/slub.c:6509 [inline]
 kfree+0x1c5/0x6d0 mm/slub.c:6802
 deactivate_locked_super+0xbe/0x110 fs/super.c:586
 cleanup_mnt+0x204/0x2a0 fs/namespace.c:1396
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x204/0x770 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
 do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888069bd2000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 296 bytes inside of
 freed 4096-byte region [ffff888069bd2000, ffff888069bd3000)
The buggy address is located 296 bytes inside of
 freed 4096-byte region [ffff888069bd2000, ffff888069bd3000)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x69bd0
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x80000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000040 ffff88813ff04140 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 0080000000000040 ffff88813ff04140 dead000000000122 0000000000000000
head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000
head: 0080000000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff
head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6393, tgid 6393 (udevadm), ts 137161243311
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1871
 prep_new_page mm/page_alloc.c:1879 [inline]
 get_page_from_freelist+0x2591/0x2600 mm/page_alloc.c:3943
 __alloc_frozen_pages_noprof+0x230/0x5c0 mm/page_alloc.c:5436
 alloc_slab_page mm/slub.c:3347 [inline]
 allocate_slab+0x7d/0x620 mm/slub.c:3462
 new_slab mm/slub.c:3513 [inline]
 refill_objects+0x2d8/0x350 mm/slub.c:7418
 refill_sheaf mm/slub.c:2885 [inline]
 __pcs_replace_empty_main+0x339/0x690 mm/slub.c:4774
 alloc_from_pcs mm/slub.c:4850 [inline]
 slab_alloc_node mm/slub.c:4984 [inline]
 __do_kmalloc_node mm/slub.c:5413 [inline]
 __kmalloc_noprof+0x54b/0x790 mm/slub.c:5439
 _kmalloc_noprof include/linux/slab.h:995 [inline]
 tomoyo_realpath_from_path+0xef/0x640 security/tomoyo/realpath.c:251
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x283/0x560 security/tomoyo/file.c:827
 security_inode_getattr+0x12b/0x310 security/security.c:1895
 vfs_getattr fs/stat.c:259 [inline]
 vfs_fstat fs/stat.c:281 [inline]
 __do_sys_newfstat fs/stat.c:551 [inline]
 __se_sys_newfstat fs/stat.c:546 [inline]
 __x64_sys_newfstat+0x133/0x270 fs/stat.c:546
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 5586 tgid 5586 ts 131641726466 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1418 [inline]
 __free_pages_ok+0xb26/0xc20 mm/page_alloc.c:1596
 zstd_free_workspace fs/btrfs/zstd.c:375 [inline]
 zstd_free_workspace_manager+0x2c7/0x390 fs/btrfs/zstd.c:226
 btrfs_free_fs_info+0x5e/0x360 fs/btrfs/disk-io.c:1230
 deactivate_locked_super+0xbe/0x110 fs/super.c:586
 cleanup_mnt+0x204/0x2a0 fs/namespace.c:1396
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x204/0x770 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:343 [inline]
 do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888069bd2000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888069bd2080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888069bd2100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                  ^
 ffff888069bd2180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888069bd2200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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