================================================================== BUG: KASAN: use-after-free in io_wq_worker_running+0xc7/0xe0 io_uring/io-wq.c:674 Read of size 4 at addr ffff888026ae3c04 by task iou-wrk-28592/28594 CPU: 1 PID: 28594 Comm: iou-wrk-28592 Not tainted 6.1.0-syzkaller #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+0x5b/0x81 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+0xc7/0xe0 io_uring/io-wq.c:674 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6691 __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:200 [inline] io_file_get_fixed io_uring/io_uring.c:1961 [inline] io_assign_file io_uring/io_uring.c:1829 [inline] io_assign_file io_uring/io_uring.c:1823 [inline] io_wq_submit_work+0x4d9/0xd30 io_uring/io_uring.c:1911 io_worker_handle_work+0x70f/0x1880 io_uring/io-wq.c:587 io_wqe_worker+0x8c4/0xc60 io_uring/io-wq.c:632 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Allocated by task 28592: 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+0x102/0x590 io_uring/io-wq.c:801 io_wqe_create_worker io_uring/io-wq.c:310 [inline] io_wqe_enqueue+0x5bf/0xb10 io_uring/io-wq.c:936 io_queue_iowq+0x226/0x490 io_uring/io_uring.c:475 io_submit_sqe io_uring/io_uring.c:2276 [inline] io_submit_sqes+0xe6f/0x1bc0 io_uring/io_uring.c:2392 __do_sys_io_uring_enter+0x8f3/0x1d00 io_uring/io_uring.c:3340 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 28594: 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+0x408/0x4d0 io_uring/io-wq.c:381 sched_submit_work kernel/sched/core.c:6598 [inline] schedule+0x16e/0x1b0 kernel/sched/core.c:6629 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6691 __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:200 [inline] io_file_get_fixed io_uring/io_uring.c:1961 [inline] io_assign_file io_uring/io_uring.c:1829 [inline] io_assign_file io_uring/io_uring.c:1823 [inline] io_wq_submit_work+0x4d9/0xd30 io_uring/io_uring.c:1911 io_worker_handle_work+0x70f/0x1880 io_uring/io-wq.c:587 io_wqe_worker+0x8c4/0xc60 io_uring/io-wq.c:632 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 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+0x71/0x220 kernel/task_work.c:48 io_queue_worker_create+0x320/0x4d0 io_uring/io-wq.c:373 sched_submit_work kernel/sched/core.c:6598 [inline] schedule+0x16e/0x1b0 kernel/sched/core.c:6629 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6691 __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:200 [inline] io_file_get_fixed io_uring/io_uring.c:1961 [inline] io_assign_file io_uring/io_uring.c:1829 [inline] io_assign_file io_uring/io_uring.c:1823 [inline] io_wq_submit_work+0x4d9/0xd30 io_uring/io_uring.c:1911 io_worker_handle_work+0x70f/0x1880 io_uring/io-wq.c:587 io_wqe_worker+0x8c4/0xc60 io_uring/io-wq.c:632 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 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+0x78/0x8f0 kernel/rcu/tree.c:3374 io_worker_exit io_uring/io-wq.c:237 [inline] io_wqe_worker+0x871/0xc60 io_uring/io-wq.c:661 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 The buggy address belongs to the object at ffff888026ae3c00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 4 bytes inside of 512-byte region [ffff888026ae3c00, ffff888026ae3e00) The buggy address belongs to the physical page: page:ffffea00009ab800 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888026ae0800 pfn:0x26ae0 head:ffffea00009ab800 order:2 compound_mapcount:0 subpages_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffff888011441c80 ffff8880114407c8 ffffea00009c9d10 raw: ffff888026ae0800 000000000010000f 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 0x152800(GFP_NOWAIT|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 31229, tgid 31229 (dhcpcd-run-hook), ts 436319338832, free_ts 435795124146 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_node include/linux/gfp.h:237 [inline] alloc_slab_page mm/slub.c:1853 [inline] allocate_slab+0xa7/0x350 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_node+0x4d/0xd0 mm/slab_common.c:975 kmalloc_array_node include/linux/slab.h:697 [inline] kcalloc_node include/linux/slab.h:702 [inline] memcg_alloc_slab_cgroups+0x8f/0x150 mm/memcontrol.c:2892 account_slab mm/slab.h:645 [inline] allocate_slab+0x2a4/0x350 mm/slub.c:2016 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] slab_alloc mm/slub.c:3460 [inline] __kmem_cache_alloc_lru mm/slub.c:3467 [inline] kmem_cache_alloc+0x379/0x430 mm/slub.c:3476 anon_vma_chain_alloc mm/rmap.c:141 [inline] anon_vma_clone+0xbf/0x520 mm/rmap.c:287 anon_vma_fork+0x70/0x630 mm/rmap.c:350 dup_mmap+0x922/0xe30 kernel/fork.c:660 dup_mm+0x86/0x330 kernel/fork.c:1548 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 __vunmap+0x66e/0xb40 mm/vmalloc.c:2727 free_work+0x4f/0x70 mm/vmalloc.c:100 process_one_work+0x8ba/0x14c0 kernel/workqueue.c:2289 worker_thread+0x59c/0xec0 kernel/workqueue.c:2436 kthread+0x298/0x340 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Memory state around the buggy address: ffff888026ae3b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888026ae3b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888026ae3c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888026ae3c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888026ae3d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================