================================================================== 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+0x7a2/0x10b0 io_uring/io_uring.c:1012 Read of size 8 at addr ffff888022cf42d8 by task kworker/1:4/8216 CPU: 1 PID: 8216 Comm: kworker/1:4 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+0x7a2/0x10b0 io_uring/io_uring.c:1012 io_uring_cmd_done+0x266/0x390 io_uring/uring_cmd.c:72 ublk_cancel_queue drivers/block/ublk_drv.c:1564 [inline] ublk_cancel_dev+0x1f7/0x3a0 drivers/block/ublk_drv.c:1577 ublk_stop_dev+0x367/0x410 drivers/block/ublk_drv.c:1678 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730 worker_thread+0xa5e/0xfe0 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 8562: 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+0x2df/0x1330 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 11: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1f0 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/0x1f0 mm/slub.c:3843 io_ring_exit_work+0x7a6/0x830 io_uring/io_uring.c:3264 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730 worker_thread+0xa5e/0xfe0 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+0xbfd/0xfd0 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+0x221/0x940 fs/file_table.c:418 task_work_run+0x1d4/0x260 kernel/task_work.c:245 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x986/0x2530 kernel/exit.c:884 do_group_exit+0x22d/0x2f0 kernel/exit.c:1026 __do_sys_exit_group kernel/exit.c:1037 [inline] __se_sys_exit_group kernel/exit.c:1035 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1035 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 The buggy address belongs to the object at ffff888022cf4000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 728 bytes inside of freed 4096-byte region [ffff888022cf4000, ffff888022cf5000) The buggy address belongs to the physical page: page:ffffea00008b3c00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x22cf0 head:ffffea00008b3c00 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 ffffea000090b800 dead000000000002 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 0x1d2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5139, tgid 5139 (udevd), ts 88845771112, free_ts 88333586913 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1582 prep_new_page mm/page_alloc.c:1589 [inline] get_page_from_freelist+0x2181/0x22a0 mm/page_alloc.c:3221 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4501 alloc_slab_page+0x5d/0x180 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2d0 mm/slub.c:2081 ___slab_alloc+0xc5c/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+0x11f/0x250 mm/slub.c:3534 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc+0xa7/0x240 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] tomoyo_realpath_from_path+0xe6/0x5c0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x224/0x460 security/tomoyo/file.c:771 security_file_open+0x62/0xa0 security/security.c:2965 do_dentry_open+0x32b/0x14b0 fs/open.c:916 do_open fs/namei.c:3640 [inline] path_openat+0x284f/0x3270 fs/namei.c:3797 do_filp_open+0x1f2/0x430 fs/namei.c:3824 do_sys_openat2+0x134/0x1d0 fs/open.c:1422 do_sys_open fs/open.c:1437 [inline] __do_sys_openat fs/open.c:1453 [inline] __se_sys_openat fs/open.c:1448 [inline] __x64_sys_openat+0x139/0x160 fs/open.c:1448 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1182 [inline] free_unref_page_prepare+0x7d7/0x8f0 mm/page_alloc.c:2366 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2459 discard_slab mm/slub.c:2127 [inline] __unfreeze_partials+0x1cf/0x210 mm/slub.c:2667 put_cpu_partial+0x17c/0x250 mm/slub.c:2743 __slab_free+0x319/0x400 mm/slub.c:3700 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+0x6a/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] __kmem_cache_alloc_node+0x194/0x250 mm/slub.c:3534 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node_track_caller+0xa4/0x230 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] mld_newpack+0x14f/0xbf0 net/ipv6/mcast.c:1743 add_grhead net/ipv6/mcast.c:1854 [inline] add_grec+0x1409/0x1910 net/ipv6/mcast.c:1992 mld_send_initial_cr+0x22d/0x4c0 net/ipv6/mcast.c:2237 Memory state around the buggy address: ffff888022cf4180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888022cf4200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888022cf4280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888022cf4300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888022cf4380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================