================================================================== BUG: KASAN: use-after-free in __io_req_task_work_add+0x6b4/0x760 io_uring/io_uring.c:1287 Read of size 8 at addr ffff888086d28858 by task syz-executor.1/15663 CPU: 1 PID: 15663 Comm: syz-executor.1 Not tainted 6.2.0-rc3-next-20230112-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:306 [inline] print_report+0x15e/0x45d mm/kasan/report.c:417 kasan_report+0xc0/0xf0 mm/kasan/report.c:517 __io_req_task_work_add+0x6b4/0x760 io_uring/io_uring.c:1287 io_req_task_work_add io_uring/io_uring.h:95 [inline] __io_poll_execute io_uring/poll.c:366 [inline] io_poll_execute.constprop.0+0x15b/0x190 io_uring/poll.c:372 io_poll_cancel_req io_uring/poll.c:379 [inline] io_poll_remove_all_table+0x26d/0x2bd io_uring/poll.c:741 io_poll_remove_all+0x2e/0x4b io_uring/poll.c:759 io_ring_ctx_wait_and_kill+0x1a0/0x340 io_uring/io_uring.c:3017 io_uring_release+0x46/0x4a io_uring/io_uring.c:3042 __fput+0x27c/0xa90 fs/file_table.c:321 task_work_run+0x16f/0x270 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xb17/0x2a90 kernel/exit.c:867 do_group_exit+0xd4/0x2a0 kernel/exit.c:1012 get_signal+0x225f/0x24f0 kernel/signal.c:2859 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f4563a8c0c9 Code: Unable to access opcode bytes at 0x7f4563a8c09f. RSP: 002b:00007f4564855168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: fffffffffffffe00 RBX: 00007f4563bac050 RCX: 00007f4563a8c0c9 RDX: 0000000000000000 RSI: 0000000000005001 RDI: 0000000000000005 RBP: 00007f4563ae7ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe1c02579f R14: 00007f4564855300 R15: 0000000000022000 Allocated by task 15652: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x7f/0x90 mm/kasan/common.c:325 kasan_slab_alloc include/linux/kasan.h:186 [inline] slab_post_alloc_hook mm/slab.h:769 [inline] slab_alloc_node mm/slub.c:3452 [inline] kmem_cache_alloc_node+0x183/0x350 mm/slub.c:3497 alloc_task_struct_node kernel/fork.c:171 [inline] dup_task_struct kernel/fork.c:979 [inline] copy_process+0x3aa/0x7740 kernel/fork.c:2103 kernel_clone+0xeb/0x9a0 kernel/fork.c:2687 __do_sys_clone+0xba/0x100 kernel/fork.c:2828 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 21: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:518 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:162 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807 slab_free mm/slub.c:3787 [inline] kmem_cache_free+0xec/0x4e0 mm/slub.c:3809 put_task_struct include/linux/sched/task.h:119 [inline] delayed_put_task_struct+0x26e/0x3f0 kernel/exit.c:225 rcu_do_batch kernel/rcu/tree.c:2113 [inline] rcu_core+0x821/0x1920 kernel/rcu/tree.c:2373 __do_softirq+0x1fb/0xaf6 kernel/softirq.c:571 Last potentially related work creation: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488 __call_rcu_common.constprop.0+0x99/0x780 kernel/rcu/tree.c:2622 put_task_struct_rcu_user+0x83/0xc0 kernel/exit.c:231 context_switch kernel/sched/core.c:5304 [inline] __schedule+0x25d8/0x5a70 kernel/sched/core.c:6619 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6788 preempt_schedule_thunk+0x1a/0x20 arch/x86/entry/thunk_64.S:34 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] _raw_spin_unlock_irq+0x40/0x50 kernel/locking/spinlock.c:202 spin_unlock_irq include/linux/spinlock.h:400 [inline] do_group_exit+0x1c5/0x2a0 kernel/exit.c:1009 __do_sys_exit_group kernel/exit.c:1023 [inline] __se_sys_exit_group kernel/exit.c:1021 [inline] __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1021 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Second to last potentially related work creation: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 __kasan_record_aux_stack+0xbc/0xd0 mm/kasan/generic.c:488 __call_rcu_common.constprop.0+0x99/0x780 kernel/rcu/tree.c:2622 put_task_struct_rcu_user+0x83/0xc0 kernel/exit.c:231 context_switch kernel/sched/core.c:5304 [inline] __schedule+0x25d8/0x5a70 kernel/sched/core.c:6619 preempt_schedule_irq+0x52/0xa0 kernel/sched/core.c:6931 irqentry_exit+0x35/0x80 kernel/entry/common.c:433 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:654 The buggy address belongs to the object at ffff888086d28000 which belongs to the cache task_struct of size 7232 The buggy address is located 2136 bytes inside of 7232-byte region [ffff888086d28000, ffff888086d29c40) The buggy address belongs to the physical page: page:ffffea00021b4a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x86d28 head:ffffea00021b4a00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88806188f4c1 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffff8880125ec500 ffffea00021b3200 dead000000000002 raw: 0000000000000000 0000000000040004 00000001ffffffff ffff88806188f4c1 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 2, tgid 2 (kthreadd), ts 390635263562, free_ts 387714635782 prep_new_page mm/page_alloc.c:2549 [inline] get_page_from_freelist+0x11bb/0x2d50 mm/page_alloc.c:4324 __alloc_pages+0x1cb/0x5c0 mm/page_alloc.c:5590 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2281 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x25f/0x350 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3193 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3292 __slab_alloc_node mm/slub.c:3345 [inline] slab_alloc_node mm/slub.c:3442 [inline] kmem_cache_alloc_node+0x136/0x350 mm/slub.c:3497 alloc_task_struct_node kernel/fork.c:171 [inline] dup_task_struct kernel/fork.c:979 [inline] copy_process+0x3aa/0x7740 kernel/fork.c:2103 kernel_clone+0xeb/0x9a0 kernel/fork.c:2687 kernel_thread+0xb9/0xf0 kernel/fork.c:2747 create_kthread kernel/kthread.c:399 [inline] kthreadd+0x4f2/0x750 kernel/kthread.c:746 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1451 [inline] free_pcp_prepare+0x4d0/0x910 mm/page_alloc.c:1501 free_unref_page_prepare mm/page_alloc.c:3387 [inline] free_unref_page+0x1d/0x490 mm/page_alloc.c:3482 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2637 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x192/0x220 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x63/0x90 mm/kasan/common.c:302 kasan_slab_alloc include/linux/kasan.h:186 [inline] slab_post_alloc_hook mm/slab.h:769 [inline] slab_alloc_node mm/slub.c:3452 [inline] kmem_cache_alloc_node+0x183/0x350 mm/slub.c:3497 __alloc_skb+0x216/0x310 net/core/skbuff.c:550 alloc_skb include/linux/skbuff.h:1270 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1202 [inline] netlink_sendmsg+0x9b0/0xe20 net/netlink/af_netlink.c:1907 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xd3/0x120 net/socket.c:734 ____sys_sendmsg+0x712/0x8c0 net/socket.c:2476 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2530 __sys_sendmsg+0xf7/0x1c0 net/socket.c:2559 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff888086d28700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888086d28780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888086d28800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888086d28880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888086d28900: fb fb fb fb fb fb fb fb fb 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