================================================================== BUG: KASAN: use-after-free in __list_del_entry_valid+0x98/0x100 lib/list_debug.c:54 Read of size 8 at addr ffff8881ce189780 by task kworker/u4:2/158 CPU: 1 PID: 158 Comm: kworker/u4:2 Not tainted 5.4.61-syzkaller-00873-ge15cc541b749 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: io_ring-wq io_sq_wq_submit_work Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x14a/0x1ce lib/dump_stack.c:118 print_address_description+0x93/0x620 mm/kasan/report.c:374 __kasan_report+0x16d/0x1e0 mm/kasan/report.c:506 kasan_report+0x36/0x60 mm/kasan/common.c:634 __list_del_entry_valid+0x98/0x100 lib/list_debug.c:54 __list_del_entry include/linux/list.h:131 [inline] list_del_init include/linux/list.h:190 [inline] io_sq_wq_submit_work+0x7f5/0x14a0 fs/io_uring.c:2272 process_one_work+0x777/0xf90 kernel/workqueue.c:2274 worker_thread+0xa8f/0x1430 kernel/workqueue.c:2420 kthread+0x317/0x340 kernel/kthread.c:268 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352 Allocated by task 329: save_stack mm/kasan/common.c:69 [inline] set_track mm/kasan/common.c:77 [inline] __kasan_kmalloc+0x12c/0x1c0 mm/kasan/common.c:510 slab_post_alloc_hook mm/slab.h:584 [inline] kmem_cache_alloc_bulk+0x1cf/0x250 mm/slub.c:3233 io_get_req+0x27f/0x850 fs/io_uring.c:650 io_submit_sqe+0x83/0xe90 fs/io_uring.c:2560 io_ring_submit fs/io_uring.c:2948 [inline] __do_sys_io_uring_enter fs/io_uring.c:3825 [inline] __se_sys_io_uring_enter+0x922/0x1ff0 fs/io_uring.c:3786 do_syscall_64+0xcb/0x150 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 158: save_stack mm/kasan/common.c:69 [inline] set_track mm/kasan/common.c:77 [inline] kasan_set_free_info mm/kasan/common.c:332 [inline] __kasan_slab_free+0x181/0x230 mm/kasan/common.c:471 slab_free_hook mm/slub.c:1443 [inline] slab_free_freelist_hook+0xd0/0x150 mm/slub.c:1476 slab_free mm/slub.c:3041 [inline] kmem_cache_free+0xac/0x600 mm/slub.c:3057 io_put_req fs/io_uring.c:762 [inline] io_poll_complete_work+0x737/0x940 fs/io_uring.c:1835 process_one_work+0x777/0xf90 kernel/workqueue.c:2274 worker_thread+0xa8f/0x1430 kernel/workqueue.c:2420 kthread+0x317/0x340 kernel/kthread.c:268 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352 The buggy address belongs to the object at ffff8881ce189680 which belongs to the cache io_kiocb of size 264 The buggy address is located 256 bytes inside of 264-byte region [ffff8881ce189680, ffff8881ce189788) The buggy address belongs to the page: page:ffffea0007386200 refcount:1 mapcount:0 mapping:ffff8881d99ba500 index:0x0 compound_mapcount: 0 flags: 0x8000000000010200(slab|head) raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881d99ba500 raw: 0000000000000000 0000000080150015 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881ce189680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881ce189700: fb fb f