================================================================== 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 ffff8880764202d8 by task kworker/1:0/23 CPU: 1 PID: 23 Comm: kworker/1:0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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:2657 [inline] process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815 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 7429: 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 12: 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:2657 [inline] process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815 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:1674 __queue_work+0xbfd/0xfd0 kernel/workqueue.c:1823 queue_work_on+0x128/0x1f0 kernel/workqueue.c:1858 queue_work include/linux/workqueue.h:564 [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:890 do_group_exit+0x22d/0x2f0 kernel/exit.c:1032 get_signal+0x12a6/0x1390 kernel/signal.c:2911 arch_do_signal_or_restart+0xc2/0x7b0 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 ffff888076420000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 728 bytes inside of freed 4096-byte region [ffff888076420000, ffff888076421000) The buggy address belongs to the physical page: page:ffffea0001d90800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x76420 head:ffffea0001d90800 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 0x1d2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 6522, tgid 6516 (syz.0.130), ts 201730296325, free_ts 198704168373 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_path_number_perm+0x248/0x5e0 security/tomoyo/file.c:723 tomoyo_path_mkdir+0xb1/0xf0 security/tomoyo/tomoyo.c:178 security_path_mkdir+0xe4/0x140 security/security.c:1771 do_mkdirat+0x162/0x450 fs/namei.c:4188 __do_sys_mkdir fs/namei.c:4211 [inline] __se_sys_mkdir fs/namei.c:4209 [inline] __x64_sys_mkdir+0x6e/0x80 fs/namei.c:4209 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:1182 [inline] free_unref_page_prepare+0x7d7/0x8f0 mm/page_alloc.c:2366 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2459 __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+0x6a/0x4d0 mm/slab.h:770 slab_alloc_node mm/slub.c:3495 [inline] __kmem_cache_alloc_node+0x194/0x250 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] fuse_io_alloc fs/fuse/file.c:744 [inline] fuse_direct_io+0x21d1/0x2bb0 fs/fuse/file.c:1548 fuse_direct_IO+0x91e/0x12f0 fs/fuse/file.c:2997 fuse_direct_write_iter fs/fuse/file.c:1648 [inline] fuse_file_write_iter+0x8b6/0xf40 fs/fuse/file.c:1696 call_write_iter include/linux/fs.h:2018 [inline] aio_write+0x564/0x7d0 fs/aio.c:1593 __io_submit_one fs/aio.c:-1 [inline] io_submit_one+0x768/0x12d0 fs/aio.c:2012 __do_sys_io_submit fs/aio.c:2071 [inline] __se_sys_io_submit+0x1a1/0x310 fs/aio.c:2041 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 Memory state around the buggy address: ffff888076420180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888076420200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888076420280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888076420300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888076420380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================