================================================================== BUG: KASAN: use-after-free in kill_fasync+0x45e/0x470 fs/fcntl.c:1014 Read of size 8 at addr ffff8880252d9d68 by task kworker/1:0/22 CPU: 1 PID: 22 Comm: kworker/1:0 Not tainted 5.19.0-rc4-next-20220628-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022 Workqueue: events key_garbage_collector Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:317 [inline] print_report.cold+0x2ba/0x719 mm/kasan/report.c:433 kasan_report+0xbe/0x1f0 mm/kasan/report.c:495 kill_fasync+0x45e/0x470 fs/fcntl.c:1014 post_one_notification.isra.0+0x6e4/0x990 kernel/watch_queue.c:128 remove_watch_from_object+0x35a/0x9d0 kernel/watch_queue.c:527 remove_watch_list include/linux/watch_queue.h:115 [inline] key_gc_unused_keys.constprop.0+0x2e5/0x600 security/keys/gc.c:135 key_garbage_collector+0x3d7/0x920 security/keys/gc.c:297 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 Allocated by task 19986: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:436 [inline] ____kasan_kmalloc mm/kasan/common.c:515 [inline] ____kasan_kmalloc mm/kasan/common.c:474 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:524 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] alloc_pipe_info+0x105/0x590 fs/pipe.c:790 get_pipe_inode fs/pipe.c:881 [inline] create_pipe_files+0x8d/0x880 fs/pipe.c:913 __do_pipe_flags fs/pipe.c:962 [inline] do_pipe2+0x96/0x1b0 fs/pipe.c:1010 __do_sys_pipe2 fs/pipe.c:1028 [inline] __se_sys_pipe2 fs/pipe.c:1026 [inline] __x64_sys_pipe2+0x50/0x70 fs/pipe.c:1026 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Freed by task 19984: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free+0x166/0x1c0 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1754 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1780 slab_free mm/slub.c:3534 [inline] kfree+0xe2/0x4d0 mm/slub.c:4562 put_pipe_info fs/pipe.c:711 [inline] pipe_release+0x2b6/0x310 fs/pipe.c:734 __fput+0x277/0x9d0 fs/file_table.c:317 task_work_run+0xdd/0x1a0 kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:169 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 kvfree_call_rcu+0x74/0x940 kernel/rcu/tree.c:3323 drop_sysctl_table+0x3c0/0x4e0 fs/proc/proc_sysctl.c:1716 unregister_sysctl_table fs/proc/proc_sysctl.c:1754 [inline] unregister_sysctl_table+0xc0/0x190 fs/proc/proc_sysctl.c:1729 retire_ipc_sysctls+0x58/0x80 ipc/ipc_sysctl.c:278 free_ipc_ns ipc/namespace.c:136 [inline] free_ipc+0x118/0x210 ipc/namespace.c:151 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 Second to last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0xbe/0xd0 mm/kasan/generic.c:348 kvfree_call_rcu+0x74/0x940 kernel/rcu/tree.c:3323 drop_sysctl_table+0x3c0/0x4e0 fs/proc/proc_sysctl.c:1716 unregister_sysctl_table fs/proc/proc_sysctl.c:1754 [inline] unregister_sysctl_table+0xc0/0x190 fs/proc/proc_sysctl.c:1729 ipv6_sysctl_net_exit+0x12d/0x1f0 net/ipv6/sysctl_net_ipv6.c:319 ops_exit_list+0xb0/0x170 net/core/net_namespace.c:163 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:595 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:302 The buggy address belongs to the object at ffff8880252d9c00 which belongs to the cache kmalloc-cg-512 of size 512 The buggy address is located 360 bytes inside of 512-byte region [ffff8880252d9c00, ffff8880252d9e00) The buggy address belongs to the physical page: page:ffffea000094b600 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880252dac00 pfn:0x252d8 head:ffffea000094b600 order:2 compound_mapcount:0 compound_pincount:0 memcg:ffff888021c4c501 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001aca900 dead000000000003 ffff888011842dc0 raw: ffff8880252dac00 000000008010000e 00000001ffffffff ffff888021c4c501 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3179, tgid 3179 (dhcpcd), ts 35212787071, free_ts 29034402341 prep_new_page mm/page_alloc.c:2535 [inline] get_page_from_freelist+0x210d/0x3a30 mm/page_alloc.c:4282 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5506 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2280 alloc_slab_page mm/slub.c:1824 [inline] allocate_slab+0x27e/0x3d0 mm/slub.c:1969 new_slab mm/slub.c:2029 [inline] ___slab_alloc+0x89d/0xef0 mm/slub.c:3031 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3118 slab_alloc_node mm/slub.c:3209 [inline] __kmalloc_node_track_caller+0x360/0x480 mm/slub.c:4955 kmalloc_reserve net/core/skbuff.c:358 [inline] __alloc_skb+0xd9/0x340 net/core/skbuff.c:430 alloc_skb include/linux/skbuff.h:1249 [inline] alloc_skb_with_frags+0x93/0x6d0 net/core/skbuff.c:5990 sock_alloc_send_pskb+0x793/0x920 net/core/sock.c:2663 unix_dgram_sendmsg+0x415/0x1b60 net/unix/af_unix.c:1884 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 __sys_sendto+0x21a/0x320 net/socket.c:2116 __do_sys_sendto net/socket.c:2128 [inline] __se_sys_sendto net/socket.c:2124 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2124 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1453 [inline] free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1503 free_unref_page_prepare mm/page_alloc.c:3383 [inline] free_unref_page+0x19/0x4d0 mm/page_alloc.c:3479 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:446 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:736 [inline] slab_alloc_node mm/slub.c:3243 [inline] slab_alloc mm/slub.c:3251 [inline] __kmem_cache_alloc_lru mm/slub.c:3258 [inline] kmem_cache_alloc+0x2d6/0x4c0 mm/slub.c:3268 getname_flags.part.0+0x50/0x4f0 fs/namei.c:139 getname_flags include/linux/audit.h:321 [inline] getname+0x8e/0xd0 fs/namei.c:218 do_sys_openat2+0xf5/0x4c0 fs/open.c:1302 do_sys_open fs/open.c:1324 [inline] __do_sys_openat fs/open.c:1340 [inline] __se_sys_openat fs/open.c:1335 [inline] __x64_sys_openat+0x13f/0x1f0 fs/open.c:1335 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Memory state around the buggy address: ffff8880252d9c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880252d9c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880252d9d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880252d9d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880252d9e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================