==================================================================
BUG: KASAN: use-after-free in io_wq_worker_running+0x114/0x130 io_uring/io-wq.c:674
Read of size 4 at addr ffff8880370ad804 by task iou-wrk-7661/7701

CPU: 1 PID: 7701 Comm: iou-wrk-7661 Not tainted 6.2.0-rc3-next-20230110-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:306 [inline]
 print_report+0x15e/0x45d mm/kasan/report.c:417
 kasan_report+0xc0/0xf0 mm/kasan/report.c:517
 io_wq_worker_running+0x114/0x130 io_uring/io-wq.c:674
 schedule_timeout+0x14e/0x2a0 kernel/time/timer.c:2167
 wait_for_avail sound/core/pcm_lib.c:1910 [inline]
 __snd_pcm_lib_xfer+0xe23/0x1cf0 sound/core/pcm_lib.c:2260
 snd_pcm_oss_read3+0x19a/0x330 sound/core/oss/pcm_oss.c:1292
 snd_pcm_oss_read2+0x300/0x3f0 sound/core/oss/pcm_oss.c:1503
 snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1531 [inline]
 snd_pcm_oss_read+0x4e3/0x7a0 sound/core/oss/pcm_oss.c:2788
 loop_rw_iter+0x1c2/0x5c0 io_uring/rw.c:464
 io_iter_do_read io_uring/rw.c:648 [inline]
 io_iter_do_read io_uring/rw.c:641 [inline]
 io_read+0x101f/0x1420 io_uring/rw.c:769
 io_issue_sqe+0x156/0x1250 io_uring/io_uring.c:1852
 io_wq_submit_work+0x29c/0xdc0 io_uring/io_uring.c:1928
 io_worker_handle_work+0xc41/0x1c60 io_uring/io-wq.c:587
 io_wqe_worker+0xa59/0xe40 io_uring/io-wq.c:632
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>

Allocated by task 7661:
 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:371 [inline]
 ____kasan_kmalloc mm/kasan/common.c:330 [inline]
 __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:380
 kmalloc_node include/linux/slab.h:606 [inline]
 kzalloc_node include/linux/slab.h:731 [inline]
 create_io_worker+0x10c/0x630 io_uring/io-wq.c:801
 create_worker_cb+0x1fb/0x270 io_uring/io-wq.c:339
 task_work_run+0x16f/0x270 kernel/task_work.c:179
 get_signal+0x1c7/0x24f0 kernel/signal.c:2635
 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297
 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 7701:
 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 mm/kasan/common.c:52
 kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:518
 ____kasan_slab_free mm/kasan/common.c:236 [inline]
 ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200
 kasan_slab_free include/linux/kasan.h:162 [inline]
 slab_free_hook mm/slub.c:1781 [inline]
 slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807
 slab_free mm/slub.c:3787 [inline]
 __kmem_cache_free+0xaf/0x2d0 mm/slub.c:3800
 io_wq_cancel_tw_create io_uring/io-wq.c:1233 [inline]
 io_queue_worker_create+0x567/0x660 io_uring/io-wq.c:381
 io_wqe_dec_running+0x1e4/0x240 io_uring/io-wq.c:410
 io_wq_worker_sleeping+0xa6/0xc0 io_uring/io-wq.c:698
 sched_submit_work kernel/sched/core.c:6661 [inline]
 schedule+0x16e/0x1b0 kernel/sched/core.c:6692
 schedule_timeout+0x14e/0x2a0 kernel/time/timer.c:2167
 wait_for_avail sound/core/pcm_lib.c:1910 [inline]
 __snd_pcm_lib_xfer+0xe23/0x1cf0 sound/core/pcm_lib.c:2260
 snd_pcm_oss_read3+0x19a/0x330 sound/core/oss/pcm_oss.c:1292
 snd_pcm_oss_read2+0x300/0x3f0 sound/core/oss/pcm_oss.c:1503
 snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1531 [inline]
 snd_pcm_oss_read+0x4e3/0x7a0 sound/core/oss/pcm_oss.c:2788
 loop_rw_iter+0x1c2/0x5c0 io_uring/rw.c:464
 io_iter_do_read io_uring/rw.c:648 [inline]
 io_iter_do_read io_uring/rw.c:641 [inline]
 io_read+0x101f/0x1420 io_uring/rw.c:769
 io_issue_sqe+0x156/0x1250 io_uring/io_uring.c:1852
 io_wq_submit_work+0x29c/0xdc0 io_uring/io_uring.c:1928
 io_worker_handle_work+0xc41/0x1c60 io_uring/io-wq.c:587
 io_wqe_worker+0xa59/0xe40 io_uring/io-wq.c:632
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

Last potentially related work creation:
 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488
 task_work_add+0x7f/0x2c0 kernel/task_work.c:48
 io_queue_worker_create+0x41d/0x660 io_uring/io-wq.c:373
 io_wqe_dec_running+0x1e4/0x240 io_uring/io-wq.c:410
 io_wq_worker_sleeping+0xa6/0xc0 io_uring/io-wq.c:698
 sched_submit_work kernel/sched/core.c:6661 [inline]
 schedule+0x16e/0x1b0 kernel/sched/core.c:6692
 schedule_timeout+0x14e/0x2a0 kernel/time/timer.c:2167
 wait_for_avail sound/core/pcm_lib.c:1910 [inline]
 __snd_pcm_lib_xfer+0xe23/0x1cf0 sound/core/pcm_lib.c:2260
 snd_pcm_oss_read3+0x19a/0x330 sound/core/oss/pcm_oss.c:1292
 snd_pcm_oss_read2+0x300/0x3f0 sound/core/oss/pcm_oss.c:1503
 snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1531 [inline]
 snd_pcm_oss_read+0x4e3/0x7a0 sound/core/oss/pcm_oss.c:2788
 loop_rw_iter+0x1c2/0x5c0 io_uring/rw.c:464
 io_iter_do_read io_uring/rw.c:648 [inline]
 io_iter_do_read io_uring/rw.c:641 [inline]
 io_read+0x101f/0x1420 io_uring/rw.c:769
 io_issue_sqe+0x156/0x1250 io_uring/io_uring.c:1852
 io_wq_submit_work+0x29c/0xdc0 io_uring/io_uring.c:1928
 io_worker_handle_work+0xc41/0x1c60 io_uring/io-wq.c:587
 io_wqe_worker+0xa59/0xe40 io_uring/io-wq.c:632
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

Second to last potentially related work creation:
 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488
 kvfree_call_rcu+0x70/0xad0 kernel/rcu/tree.c:3315
 drop_sysctl_table+0x3c2/0x4e0 fs/proc/proc_sysctl.c:1709
 unregister_sysctl_table fs/proc/proc_sysctl.c:1747 [inline]
 unregister_sysctl_table+0xc4/0x190 fs/proc/proc_sysctl.c:1722
 neigh_sysctl_unregister+0x5f/0x80 net/core/neighbour.c:3873
 addrconf_ifdown.isra.0+0x1350/0x1940 net/ipv6/addrconf.c:3903
 addrconf_notify+0x109/0x1cd0 net/ipv6/addrconf.c:3673
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1944
 call_netdevice_notifiers_extack net/core/dev.c:1982 [inline]
 call_netdevice_notifiers net/core/dev.c:1996 [inline]
 unregister_netdevice_many_notify+0xa2b/0x19e0 net/core/dev.c:10839
 vti6_exit_batch_net+0x3c3/0x730 net/ipv6/ip6_vti.c:1188
 ops_exit_list+0x125/0x170 net/core/net_namespace.c:174
 cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:606
 process_one_work+0x9bf/0x1750 kernel/workqueue.c:2293
 worker_thread+0x669/0x1090 kernel/workqueue.c:2440
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

The buggy address belongs to the object at ffff8880370ad800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 4 bytes inside of
 512-byte region [ffff8880370ad800, ffff8880370ada00)

The buggy address belongs to the physical page:
page:ffffea0000dc2b00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x370ac
head:ffffea0000dc2b00 order:2 compound_mapcount:0 subpages_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffff888012441c80 ffffea0001c23b00 dead000000000002
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5117, tgid 5117 (syz-executor.4), ts 240500975077, free_ts 0
 prep_new_page mm/page_alloc.c:2546 [inline]
 get_page_from_freelist+0x119e/0x2a80 mm/page_alloc.c:4298
 __alloc_pages+0x1cb/0x5c0 mm/page_alloc.c:5564
 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2272
 alloc_slab_page mm/slub.c:1851 [inline]
 allocate_slab+0x25f/0x350 mm/slub.c:1998
 new_slab mm/slub.c:2051 [inline]
 ___slab_alloc+0xa91/0x1400 mm/slub.c:3193
 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3292
 __slab_alloc_node mm/slub.c:3345 [inline]
 slab_alloc_node mm/slub.c:3442 [inline]
 __kmem_cache_alloc_node+0x136/0x330 mm/slub.c:3491
 __do_kmalloc_node mm/slab_common.c:966 [inline]
 __kmalloc_node_track_caller+0x4b/0xc0 mm/slab_common.c:987
 kmalloc_reserve net/core/skbuff.c:490 [inline]
 __alloc_skb+0xe9/0x310 net/core/skbuff.c:563
 alloc_skb include/linux/skbuff.h:1270 [inline]
 nlmsg_new include/net/netlink.h:1002 [inline]
 mpls_netconf_notify_devconf+0x4a/0x110 net/mpls/af_mpls.c:1188
 mpls_dev_sysctl_register+0x1fe/0x2d0 net/mpls/af_mpls.c:1425
 mpls_add_dev net/mpls/af_mpls.c:1472 [inline]
 mpls_dev_notify+0x46d/0x990 net/mpls/af_mpls.c:1612
 notifier_call_chain+0xb5/0x200 kernel/notifier.c:87
 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1944
 call_netdevice_notifiers_extack net/core/dev.c:1982 [inline]
 call_netdevice_notifiers net/core/dev.c:1996 [inline]
 register_netdevice+0xfb4/0x1640 net/core/dev.c:10078
 veth_newlink+0x33c/0x9a0 drivers/net/veth.c:1765
page_owner free stack trace missing

Memory state around the buggy address:
 ffff8880370ad700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880370ad780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880370ad800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff8880370ad880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880370ad900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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