================================================================== BUG: KASAN: use-after-free in io_wq_worker_running+0x114/0x130 io_uring/io-wq.c:674 Read of size 4 at addr ffff888040665c04 by task iou-wrk-17527/17556 CPU: 1 PID: 17556 Comm: iou-wrk-17527 Not tainted 6.2.0-rc3-syzkaller-00021-g7dd4b804e080 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __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+0xbf/0x1f0 mm/kasan/report.c:517 io_wq_worker_running+0x114/0x130 io_uring/io-wq.c:674 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6690 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0xa48/0x1360 kernel/locking/mutex.c:747 io_ring_submit_lock io_uring/io_uring.h:215 [inline] io_file_get_fixed io_uring/io_uring.c:1966 [inline] io_assign_file io_uring/io_uring.c:1834 [inline] io_assign_file io_uring/io_uring.c:1828 [inline] io_wq_submit_work+0x5f7/0xdc0 io_uring/io_uring.c:1916 io_worker_handle_work+0xc41/0x1c60 io_uring/io-wq.c:587 io_wqe_worker+0xa5b/0xe40 io_uring/io-wq.c:632 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Allocated by task 17527: 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+0xa5/0xb0 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 io_wqe_create_worker io_uring/io-wq.c:310 [inline] io_wqe_enqueue+0x6c3/0xbc0 io_uring/io-wq.c:936 io_queue_iowq+0x282/0x5c0 io_uring/io_uring.c:475 io_queue_sqe_fallback+0xf3/0x190 io_uring/io_uring.c:2059 io_submit_sqe io_uring/io_uring.c:2281 [inline] io_submit_sqes+0x11db/0x1e60 io_uring/io_uring.c:2397 __do_sys_io_uring_enter+0xc1d/0x2540 io_uring/io_uring.c:3345 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 17556: 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:177 [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/0x3b0 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:6597 [inline] schedule+0x16e/0x1b0 kernel/sched/core.c:6628 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6690 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0xa48/0x1360 kernel/locking/mutex.c:747 io_ring_submit_lock io_uring/io_uring.h:215 [inline] io_file_get_fixed io_uring/io_uring.c:1966 [inline] io_assign_file io_uring/io_uring.c:1834 [inline] io_assign_file io_uring/io_uring.c:1828 [inline] io_wq_submit_work+0x5f7/0xdc0 io_uring/io_uring.c:1916 io_worker_handle_work+0xc41/0x1c60 io_uring/io-wq.c:587 io_wqe_worker+0xa5b/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:6597 [inline] schedule+0x16e/0x1b0 kernel/sched/core.c:6628 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6690 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0xa48/0x1360 kernel/locking/mutex.c:747 io_ring_submit_lock io_uring/io_uring.h:215 [inline] io_file_get_fixed io_uring/io_uring.c:1966 [inline] io_assign_file io_uring/io_uring.c:1834 [inline] io_assign_file io_uring/io_uring.c:1828 [inline] io_wq_submit_work+0x5f7/0xdc0 io_uring/io_uring.c:1916 io_worker_handle_work+0xc41/0x1c60 io_uring/io-wq.c:587 io_wqe_worker+0xa5b/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 insert_work+0x48/0x350 kernel/workqueue.c:1358 __queue_work+0x693/0x13b0 kernel/workqueue.c:1517 call_timer_fn+0x1da/0x7c0 kernel/time/timer.c:1700 expire_timers+0xbb/0x5c0 kernel/time/timer.c:1746 __run_timers kernel/time/timer.c:2022 [inline] __run_timers kernel/time/timer.c:1995 [inline] run_timer_softirq+0x326/0x910 kernel/time/timer.c:2035 __do_softirq+0x1fb/0xadc kernel/softirq.c:571 The buggy address belongs to the object at ffff888040665c00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 4 bytes inside of 512-byte region [ffff888040665c00, ffff888040665e00) The buggy address belongs to the physical page: page:ffffea0001019900 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x40664 head:ffffea0001019900 order:2 compound_mapcount:0 subpages_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffff888012441c80 ffffea000101e300 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 5105, tgid 5105 (syz-executor.1), ts 157706925795, free_ts 13368718868 prep_new_page mm/page_alloc.c:2531 [inline] get_page_from_freelist+0x119c/0x2ce0 mm/page_alloc.c:4283 __alloc_pages+0x1cb/0x5b0 mm/page_alloc.c:5549 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2286 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+0x1a4/0x430 mm/slub.c:3491 __do_kmalloc_node mm/slab_common.c:967 [inline] __kmalloc+0x4a/0xd0 mm/slab_common.c:981 kmalloc include/linux/slab.h:584 [inline] kzalloc include/linux/slab.h:720 [inline] new_dir fs/proc/proc_sysctl.c:971 [inline] get_subdir fs/proc/proc_sysctl.c:1015 [inline] __register_sysctl_table+0x9ef/0x10a0 fs/proc/proc_sysctl.c:1366 neigh_sysctl_register+0x2cc/0x5f0 net/core/neighbour.c:3854 addrconf_sysctl_register+0xb6/0x1d0 net/ipv6/addrconf.c:7126 ipv6_add_dev+0xa80/0x1320 net/ipv6/addrconf.c:450 addrconf_notify+0x85c/0x1c80 net/ipv6/addrconf.c:3528 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 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1446 [inline] free_pcp_prepare+0x65c/0xc00 mm/page_alloc.c:1496 free_unref_page_prepare mm/page_alloc.c:3369 [inline] free_unref_page+0x1d/0x490 mm/page_alloc.c:3464 free_contig_range+0xb5/0x180 mm/page_alloc.c:9485 destroy_args+0xa8/0x64c mm/debug_vm_pgtable.c:998 debug_vm_pgtable+0x28de/0x296f mm/debug_vm_pgtable.c:1318 do_one_initcall+0x141/0x790 init/main.c:1306 do_initcall_level init/main.c:1379 [inline] do_initcalls init/main.c:1395 [inline] do_basic_setup init/main.c:1414 [inline] kernel_init_freeable+0x6f9/0x782 init/main.c:1634 kernel_init+0x1e/0x1d0 init/main.c:1522 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Memory state around the buggy address: ffff888040665b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888040665b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888040665c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888040665c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888040665d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================