================================================================== BUG: KASAN: slab-use-after-free in list_empty include/linux/list.h:373 [inline] BUG: KASAN: slab-use-after-free in waitqueue_active include/linux/wait.h:129 [inline] BUG: KASAN: slab-use-after-free in wq_has_sleeper include/linux/wait.h:163 [inline] BUG: KASAN: slab-use-after-free in io_cqring_wake io_uring/io_uring.h:260 [inline] BUG: KASAN: slab-use-after-free in io_cq_unlock_post io_uring/io_uring.c:647 [inline] BUG: KASAN: slab-use-after-free in __io_req_complete_post+0x797/0x10a0 io_uring/io_uring.c:1012 Read of size 8 at addr ffff88807c3a42d8 by task kworker/1:5/6148 CPU: 1 PID: 6148 Comm: kworker/1:5 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: events ublk_stop_work_fn Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xa8/0x210 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 list_empty include/linux/list.h:373 [inline] waitqueue_active include/linux/wait.h:129 [inline] wq_has_sleeper include/linux/wait.h:163 [inline] io_cqring_wake io_uring/io_uring.h:260 [inline] io_cq_unlock_post io_uring/io_uring.c:647 [inline] __io_req_complete_post+0x797/0x10a0 io_uring/io_uring.c:1012 io_uring_cmd_done+0x247/0x370 io_uring/uring_cmd.c:72 ublk_cancel_queue drivers/block/ublk_drv.c:1564 [inline] ublk_cancel_dev+0x1f5/0x3a0 drivers/block/ublk_drv.c:1577 ublk_stop_dev+0x36e/0x410 drivers/block/ublk_drv.c:1678 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Allocated by task 7678: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] io_ring_ctx_alloc+0x54/0xc10 io_uring/io_uring.c:289 io_uring_create+0x2de/0x1320 io_uring/io_uring.c:3993 io_uring_setup io_uring/io_uring.c:4178 [inline] __do_sys_io_uring_setup io_uring/io_uring.c:4205 [inline] __se_sys_io_uring_setup+0x29f/0x2b0 io_uring/io_uring.c:4199 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 994: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] __kmem_cache_free+0xba/0x1e0 mm/slub.c:3843 io_ring_exit_work+0x795/0x820 io_uring/io_uring.c:3264 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 insert_work+0x3d/0x310 kernel/workqueue.c:1670 __queue_work+0xc39/0x1020 kernel/workqueue.c:1819 queue_work_on+0x128/0x1f0 kernel/workqueue.c:1854 queue_work include/linux/workqueue.h:562 [inline] io_ring_ctx_wait_and_kill+0x256/0x2b0 io_uring/io_uring.c:3296 io_uring_release+0x42/0x50 io_uring/io_uring.c:3304 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1d4/0x260 kernel/task_work.c:245 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x95a/0x2460 kernel/exit.c:884 do_group_exit+0x21b/0x2d0 kernel/exit.c:1026 get_signal+0x12fc/0x13f0 kernel/signal.c:2902 arch_do_signal_or_restart+0xc2/0x800 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88807c3a4000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 728 bytes inside of freed 4096-byte region [ffff88807c3a4000, ffff88807c3a5000) The buggy address belongs to the physical page: page:ffffea0001f0e800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7c3a0 head:ffffea0001f0e800 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017c42140 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 6081, tgid 6081 (kworker/u4:16), ts 398483137990, free_ts 398377794620 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1581 prep_new_page mm/page_alloc.c:1588 [inline] get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3220 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4500 alloc_slab_page+0x5d/0x160 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2d0 mm/slub.c:2081 ___slab_alloc+0xc5d/0x12f0 mm/slub.c:3253 __slab_alloc mm/slub.c:3339 [inline] __slab_alloc_node mm/slub.c:3392 [inline] slab_alloc_node mm/slub.c:3485 [inline] __kmem_cache_alloc_node+0x19e/0x250 mm/slub.c:3534 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node_track_caller+0xa2/0x230 mm/slab_common.c:1027 kmalloc_reserve+0x116/0x240 net/core/skbuff.c:584 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653 alloc_skb include/linux/skbuff.h:1316 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x293/0xb10 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1181 [inline] free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2365 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458 __slab_free+0x35a/0x400 mm/slub.c:3736 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x11a/0x2d0 mm/slub.c:3519 ptlock_alloc+0x20/0x70 mm/memory.c:6177 ptlock_init include/linux/mm.h:2964 [inline] pagetable_pte_ctor include/linux/mm.h:2987 [inline] __pte_alloc_one include/asm-generic/pgalloc.h:71 [inline] pte_alloc_one+0xcc/0x530 arch/x86/mm/pgtable.c:33 __pte_alloc+0x22/0x2a0 mm/memory.c:438 copy_pte_range mm/memory.c:1029 [inline] copy_pmd_range mm/memory.c:1168 [inline] copy_pud_range mm/memory.c:1205 [inline] copy_p4d_range mm/memory.c:1229 [inline] copy_page_range+0x2d96/0x3670 mm/memory.c:1323 dup_mmap kernel/fork.c:769 [inline] dup_mm kernel/fork.c:1694 [inline] copy_mm+0x1281/0x1d80 kernel/fork.c:1743 copy_process+0x16f7/0x3dc0 kernel/fork.c:2508 kernel_clone+0x24b/0x8a0 kernel/fork.c:2917 __do_sys_clone kernel/fork.c:3060 [inline] __se_sys_clone kernel/fork.c:3044 [inline] __x64_sys_clone+0x1b7/0x230 kernel/fork.c:3044 Memory state around the buggy address: ffff88807c3a4180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807c3a4200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807c3a4280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807c3a4300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807c3a4380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================