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BUG: KASAN: use-after-free in mutex_can_spin_on_owner kernel/locking/mutex.c:617 [inline]
BUG: KASAN: use-after-free in mutex_optimistic_spin kernel/locking/mutex.c:661 [inline]
BUG: KASAN: use-after-free in __mutex_lock_common kernel/locking/mutex.c:973 [inline]
BUG: KASAN: use-after-free in __mutex_lock+0xcd7/0x1060 kernel/locking/mutex.c:1114
Read of size 4 at addr ffff8881f32fbf38 by task syz-executor.1/481

CPU: 0 PID: 481 Comm: syz-executor.1 Not tainted 5.4.283-syzkaller-04984-ge6ac8beecb16 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d8/0x241 lib/dump_stack.c:118
 print_address_description+0x8c/0x600 mm/kasan/report.c:384
 __kasan_report+0xf3/0x120 mm/kasan/report.c:516
 kasan_report+0x30/0x60 mm/kasan/common.c:653
 mutex_can_spin_on_owner kernel/locking/mutex.c:617 [inline]
 mutex_optimistic_spin kernel/locking/mutex.c:661 [inline]
 __mutex_lock_common kernel/locking/mutex.c:973 [inline]
 __mutex_lock+0xcd7/0x1060 kernel/locking/mutex.c:1114
 mutex_lock_killable+0xd8/0x110 kernel/locking/mutex.c:1348
 lo_open+0x18/0xc0 drivers/block/loop.c:1899
 __blkdev_get+0x3c8/0x1160 fs/block_dev.c:1581
 blkdev_get+0x2de/0x3a0 fs/block_dev.c:1714
 do_dentry_open+0x964/0x1130 fs/open.c:806
 do_last fs/namei.c:3565 [inline]
 path_openat+0x29bf/0x34b0 fs/namei.c:3683
 do_filp_open+0x20b/0x450 fs/namei.c:3713
 do_sys_open+0x39c/0x810 fs/open.c:1123
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
RIP: 0033:0x7f103bbb8921
Code: 75 57 89 f0 25 00 00 41 00 3d 00 00 41 00 74 49 80 3d ea 35 10 00 00 74 6d 89 da 48 89 ee bf 9c ff ff ff b8 01 01 00 00 0f 05 <48> 3d 00 f0 ff ff 0f 87 93 00 00 00 48 8b 54 24 28 64 48 2b 14 25
RSP: 002b:00007ffc041b6c00 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f103bbb8921
RDX: 0000000000000002 RSI: 00007ffc041b6d40 RDI: 00000000ffffff9c
RBP: 00007ffc041b6d40 R08: 000000000000000a R09: 00007ffc041b69c7
R10: 0000000000000000 R11: 0000000000000202 R12: 00007f103bcb5e28
R13: 00007f103bcb5120 R14: 0000000000000003 R15: 00007ffc041b6d40

Allocated by task 447:
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 __kasan_kmalloc+0x171/0x210 mm/kasan/common.c:529
 slab_post_alloc_hook mm/slab.h:584 [inline]
 slab_alloc_node mm/slub.c:2829 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 kmem_cache_alloc+0xd9/0x250 mm/slub.c:2842
 kmem_cache_alloc_node include/linux/slab.h:427 [inline]
 alloc_task_struct_node kernel/fork.c:171 [inline]
 dup_task_struct+0x4f/0x600 kernel/fork.c:882
 copy_process+0x56d/0x3230 kernel/fork.c:1889
 _do_fork+0x197/0x900 kernel/fork.c:2399
 __do_sys_clone3 kernel/fork.c:2688 [inline]
 __se_sys_clone3 kernel/fork.c:2675 [inline]
 __x64_sys_clone3+0x2da/0x300 kernel/fork.c:2675
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Freed by task 10:
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 kasan_set_free_info mm/kasan/common.c:345 [inline]
 __kasan_slab_free+0x1b5/0x270 mm/kasan/common.c:487
 slab_free_hook mm/slub.c:1455 [inline]
 slab_free_freelist_hook mm/slub.c:1494 [inline]
 slab_free mm/slub.c:3080 [inline]
 kmem_cache_free+0x10b/0x2c0 mm/slub.c:3096
 __rcu_reclaim kernel/rcu/rcu.h:222 [inline]
 rcu_do_batch+0x492/0xa00 kernel/rcu/tree.c:2167
 rcu_core+0x4c8/0xcb0 kernel/rcu/tree.c:2387
 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292

The buggy address belongs to the object at ffff8881f32fbf00
 which belongs to the cache task_struct of size 3904
The buggy address is located 56 bytes inside of
 3904-byte region [ffff8881f32fbf00, ffff8881f32fce40)
The buggy address belongs to the page:
page:ffffea0007ccbe00 refcount:1 mapcount:0 mapping:ffff8881f5cf9900 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5cf9900
raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC)
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook mm/page_alloc.c:2165 [inline]
 prep_new_page+0x18f/0x370 mm/page_alloc.c:2171
 get_page_from_freelist+0x2d13/0x2d90 mm/page_alloc.c:3794
 __alloc_pages_nodemask+0x393/0x840 mm/page_alloc.c:4893
 alloc_slab_page+0x39/0x3c0 mm/slub.c:343
 allocate_slab mm/slub.c:1683 [inline]
 new_slab+0x97/0x440 mm/slub.c:1749
 new_slab_objects mm/slub.c:2505 [inline]
 ___slab_alloc+0x2fe/0x490 mm/slub.c:2667
 __slab_alloc+0x62/0xa0 mm/slub.c:2707
 slab_alloc_node mm/slub.c:2792 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 kmem_cache_alloc+0x109/0x250 mm/slub.c:2842
 kmem_cache_alloc_node include/linux/slab.h:427 [inline]
 alloc_task_struct_node kernel/fork.c:171 [inline]
 dup_task_struct+0x4f/0x600 kernel/fork.c:882
 copy_process+0x56d/0x3230 kernel/fork.c:1889
 _do_fork+0x197/0x900 kernel/fork.c:2399
 kernel_thread+0x16a/0x1d0 kernel/fork.c:2489
 create_kthread kernel/kthread.c:311 [inline]
 kthreadd+0x3b1/0x4f0 kernel/kthread.c:654
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1176 [inline]
 __free_pages_ok+0x847/0x950 mm/page_alloc.c:1438
 free_the_page mm/page_alloc.c:4955 [inline]
 __free_pages+0x91/0x140 mm/page_alloc.c:4961
 free_thread_stack kernel/fork.c:299 [inline]
 release_task_stack kernel/fork.c:439 [inline]
 put_task_stack+0x212/0x260 kernel/fork.c:450
 finish_task_switch+0x24a/0x590 kernel/sched/core.c:3479
 context_switch kernel/sched/core.c:3611 [inline]
 __schedule+0xb0d/0x1320 kernel/sched/core.c:4307
 schedule_idle+0x50/0x80 kernel/sched/core.c:4403
 do_idle+0x609/0x660 kernel/sched/idle.c:288
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:356
 start_kernel+0x6d9/0x81d init/main.c:1036
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241

Memory state around the buggy address:
 ffff8881f32fbe00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881f32fbe80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8881f32fbf00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff8881f32fbf80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881f32fc000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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