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BUG: KASAN: use-after-free in radix_tree_next_slot include/linux/radix-tree.h:422 [inline]
BUG: KASAN: use-after-free in idr_for_each+0x206/0x220 lib/idr.c:202
Read of size 8 at addr ffff88807a2ea878 by task syz-executor.5/23805

CPU: 1 PID: 23805 Comm: syz-executor.5 Not tainted 5.11.0-rc3-next-20210115-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:230
 __kasan_report mm/kasan/report.c:397 [inline]
 kasan_report.cold+0x79/0xd5 mm/kasan/report.c:414
 radix_tree_next_slot include/linux/radix-tree.h:422 [inline]
 idr_for_each+0x206/0x220 lib/idr.c:202
 io_ring_ctx_wait_and_kill+0x1bd/0x600 fs/io_uring.c:8762
 io_uring_release+0x3e/0x50 fs/io_uring.c:8787
 __fput+0x283/0x920 fs/file_table.c:280
 task_work_run+0xdd/0x190 kernel/task_work.c:140
 exit_task_work include/linux/task_work.h:30 [inline]
 do_exit+0xc5c/0x2ae0 kernel/exit.c:825
 do_group_exit+0x125/0x310 kernel/exit.c:922
 get_signal+0x3e9/0x20a0 kernel/signal.c:2770
 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811
 handle_signal_work kernel/entry/common.c:150 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
 exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:301 [inline]
 syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:312
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45e219
Code: Unable to access opcode bytes at RIP 0x45e1ef.
RSP: 002b:00007f4f55c3ccf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 000000000119c030 RCX: 000000000045e219
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 000000000119c034
RBP: 000000000119c028 R08: 0000000000000009 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 000000000119c034
R13: 00007ffcbe0e9e6f R14: 00007f4f55c3d9c0 R15: 000000000119c034

Allocated by task 23795:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:403 [inline]
 ____kasan_kmalloc mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc.constprop.0+0xa0/0xd0 mm/kasan/common.c:406
 kasan_slab_alloc include/linux/kasan.h:209 [inline]
 slab_post_alloc_hook mm/slab.h:518 [inline]
 slab_alloc_node mm/slub.c:2903 [inline]
 slab_alloc mm/slub.c:2911 [inline]
 kmem_cache_alloc+0x155/0x370 mm/slub.c:2916
 radix_tree_node_alloc.constprop.0+0x7c/0x350 lib/radix-tree.c:274
 idr_get_free+0x554/0xa60 lib/radix-tree.c:1504
 idr_alloc_u32+0x170/0x2d0 lib/idr.c:46
 idr_alloc_cyclic+0x102/0x230 lib/idr.c:125
 io_register_personality fs/io_uring.c:9827 [inline]
 __io_uring_register fs/io_uring.c:10056 [inline]
 __do_sys_io_uring_register+0x15b1/0x40b0 fs/io_uring.c:10106
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 19:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357
 ____kasan_slab_free.part.0+0xe1/0x110 mm/kasan/common.c:364
 kasan_slab_free include/linux/kasan.h:192 [inline]
 slab_free_hook mm/slub.c:1548 [inline]
 slab_free_freelist_hook+0x82/0x1d0 mm/slub.c:1586
 slab_free mm/slub.c:3157 [inline]
 kmem_cache_free+0x8b/0x740 mm/slub.c:3173
 rcu_do_batch kernel/rcu/tree.c:2531 [inline]
 rcu_core+0x746/0x1390 kernel/rcu/tree.c:2766
 __do_softirq+0x2bc/0xa29 kernel/softirq.c:343

Last potentially related work creation:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_record_aux_stack+0xe5/0x110 mm/kasan/generic.c:345
 __call_rcu kernel/rcu/tree.c:3011 [inline]
 call_rcu+0xbb/0x750 kernel/rcu/tree.c:3086
 radix_tree_node_free lib/radix-tree.c:308 [inline]
 delete_node+0x591/0x8c0 lib/radix-tree.c:571
 __radix_tree_delete+0x190/0x370 lib/radix-tree.c:1377
 radix_tree_delete_item+0xe7/0x230 lib/radix-tree.c:1428
 io_remove_personalities+0x1d/0x170 fs/io_uring.c:8707
 idr_for_each+0x113/0x220 lib/idr.c:208
 io_ring_ctx_wait_and_kill+0x1bd/0x600 fs/io_uring.c:8762
 io_uring_release+0x3e/0x50 fs/io_uring.c:8787
 __fput+0x283/0x920 fs/file_table.c:280
 task_work_run+0xdd/0x190 kernel/task_work.c:140
 exit_task_work include/linux/task_work.h:30 [inline]
 do_exit+0xc5c/0x2ae0 kernel/exit.c:825
 do_group_exit+0x125/0x310 kernel/exit.c:922
 get_signal+0x3e9/0x20a0 kernel/signal.c:2770
 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811
 handle_signal_work kernel/entry/common.c:150 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
 exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:301 [inline]
 syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:312
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff88807a2ea840
 which belongs to the cache radix_tree_node of size 576
The buggy address is located 56 bytes inside of
 576-byte region [ffff88807a2ea840, ffff88807a2eaa80)
The buggy address belongs to the page:
page:00000000ec533045 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7a2ea
head:00000000ec533045 order:1 compound_mapcount:0
flags: 0xfff00000010200(slab|head)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff88801004db40
raw: 0000000000000000 00000000800b000b 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88807a2ea700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807a2ea780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff88807a2ea800: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
                                                                ^
 ffff88807a2ea880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88807a2ea900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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