================================================================== 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 ffff8880278622d8 by task kworker/1:6/12776 CPU: 1 PID: 12776 Comm: kworker/1:6 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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 19914: 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 8599: 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 ffff888027862000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 728 bytes inside of freed 4096-byte region [ffff888027862000, ffff888027863000) The buggy address belongs to the physical page: page:ffffea00009e1800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x27860 head:ffffea00009e1800 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 dead000000000100 dead000000000122 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5151, tgid 5151 (udevd), ts 45335258379, free_ts 45306600503 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 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] kernfs_iop_get_link+0x66/0x660 fs/kernfs/symlink.c:135 vfs_readlink+0x168/0x350 fs/namei.c:5129 do_readlinkat+0x255/0x490 fs/stat.c:506 __do_sys_readlink fs/stat.c:527 [inline] __se_sys_readlink fs/stat.c:524 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:524 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 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 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+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_lru+0x111/0x2d0 mm/slub.c:3526 __d_alloc+0x31/0x730 fs/dcache.c:1773 d_alloc fs/dcache.c:1853 [inline] d_alloc_parallel+0xe0/0x1530 fs/dcache.c:2646 __lookup_slow+0x138/0x400 fs/namei.c:1687 lookup_slow+0x53/0x70 fs/namei.c:1719 walk_component+0x2be/0x3f0 fs/namei.c:2010 lookup_last fs/namei.c:2467 [inline] path_lookupat+0x169/0x440 fs/namei.c:2491 Memory state around the buggy address: ffff888027862180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888027862200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888027862280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888027862300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888027862380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================