================================================================== BUG: KASAN: use-after-free in kill_fasync+0x3a/0x430 fs/fcntl.c:1014 Read of size 8 at addr ffff88807ff3a568 by task kworker/1:12/9039 CPU: 1 PID: 9039 Comm: kworker/1:12 Not tainted 5.19.0-rc6-syzkaller-00111-gb047602d579b #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+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description+0x65/0x4b0 mm/kasan/report.c:313 print_report+0xf4/0x210 mm/kasan/report.c:429 kasan_report+0xfb/0x130 mm/kasan/report.c:491 kill_fasync+0x3a/0x430 fs/fcntl.c:1014 remove_watch_from_object+0x4d0/0xa70 kernel/watch_queue.c:527 remove_watch_list include/linux/watch_queue.h:115 [inline] key_gc_unused_keys+0x1c3/0x5b0 security/keys/gc.c:135 key_garbage_collector+0x8cc/0xa10 security/keys/gc.c:297 process_one_work+0x81c/0xd10 kernel/workqueue.c:2289 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 Allocated by task 9282: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:436 [inline] ____kasan_kmalloc+0xdc/0x110 mm/kasan/common.c:515 kasan_kmalloc include/linux/kasan.h:234 [inline] kmem_cache_alloc_trace+0x94/0x310 mm/slub.c:3284 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] alloc_pipe_info+0xe2/0x4a0 fs/pipe.c:790 get_pipe_inode fs/pipe.c:881 [inline] create_pipe_files+0x84/0x6e0 fs/pipe.c:913 __do_pipe_flags+0x46/0x200 fs/pipe.c:962 do_pipe2+0xd0/0x300 fs/pipe.c:1010 __do_sys_pipe2 fs/pipe.c:1028 [inline] __se_sys_pipe2 fs/pipe.c:1026 [inline] __x64_sys_pipe2+0x56/0x60 fs/pipe.c:1026 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 9280: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4c/0x70 mm/kasan/common.c:45 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0xd8/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1754 [inline] slab_free_freelist_hook+0x12e/0x1a0 mm/slub.c:1780 slab_free mm/slub.c:3536 [inline] kfree+0xc6/0x210 mm/slub.c:4584 put_pipe_info fs/pipe.c:711 [inline] pipe_release+0x232/0x310 fs/pipe.c:734 __fput+0x3b9/0x820 fs/file_table.c:317 task_work_run+0x146/0x1c0 kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0x134/0x160 kernel/entry/common.c:169 exit_to_user_mode_prepare+0xad/0x110 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x2e/0x60 kernel/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x63/0xcd Last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:348 kvfree_call_rcu+0x118/0x840 kernel/rcu/tree.c:3647 drop_sysctl_table+0x31c/0x460 fs/proc/proc_sysctl.c:1716 unregister_sysctl_table+0x87/0x140 fs/proc/proc_sysctl.c:1754 ipv6_sysctl_net_exit+0x138/0x190 net/ipv6/sysctl_net_ipv6.c:319 ops_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x758/0xc50 net/core/net_namespace.c:594 process_one_work+0x81c/0xd10 kernel/workqueue.c:2289 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 Second to last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:38 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:348 kvfree_call_rcu+0x118/0x840 kernel/rcu/tree.c:3647 drop_sysctl_table+0x31c/0x460 fs/proc/proc_sysctl.c:1716 unregister_sysctl_table+0x87/0x140 fs/proc/proc_sysctl.c:1754 mptcp_pernet_del_table net/mptcp/ctrl.c:172 [inline] mptcp_net_exit+0x59/0x70 net/mptcp/ctrl.c:202 ops_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x758/0xc50 net/core/net_namespace.c:594 process_one_work+0x81c/0xd10 kernel/workqueue.c:2289 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 The buggy address belongs to the object at ffff88807ff3a400 which belongs to the cache kmalloc-cg-512 of size 512 The buggy address is located 360 bytes inside of 512-byte region [ffff88807ff3a400, ffff88807ff3a600) The buggy address belongs to the physical page: page:ffffea0001ffce00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88807ff3bc00 pfn:0x7ff38 head:ffffea0001ffce00 order:2 compound_mapcount:0 compound_pincount:0 memcg:ffff888025f14101 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001ef2e00 dead000000000002 ffff888011c42dc0 raw: ffff88807ff3bc00 000000008010000b 00000001ffffffff ffff888025f14101 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 3702, tgid 3702 (syz-executor.4), ts 133275751948, free_ts 133261340769 prep_new_page mm/page_alloc.c:2456 [inline] get_page_from_freelist+0x72b/0x7a0 mm/page_alloc.c:4198 __alloc_pages+0x259/0x560 mm/page_alloc.c:5426 alloc_slab_page+0x70/0xf0 mm/slub.c:1824 allocate_slab+0x5e/0x520 mm/slub.c:1969 new_slab mm/slub.c:2029 [inline] ___slab_alloc+0x42e/0xce0 mm/slub.c:3031 __slab_alloc mm/slub.c:3118 [inline] slab_alloc_node mm/slub.c:3209 [inline] slab_alloc mm/slub.c:3251 [inline] kmem_cache_alloc_trace+0x25c/0x310 mm/slub.c:3282 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] ipv6_add_addr+0x421/0xe50 net/ipv6/addrconf.c:1099 addrconf_add_linklocal+0x2ff/0x630 net/ipv6/addrconf.c:3215 addrconf_addr_gen+0x2c6/0x410 net/ipv6/addrconf.c:3346 addrconf_notify+0xaed/0xf80 net/ipv6/addrconf.c:3631 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xe7/0x170 kernel/notifier.c:455 __dev_notify_flags+0x2ef/0x5f0 dev_change_flags+0xe3/0x190 net/core/dev.c:8609 do_setlink+0xdb2/0x3f00 net/core/rtnetlink.c:2780 __rtnl_newlink net/core/rtnetlink.c:3546 [inline] rtnl_newlink+0x183e/0x2060 net/core/rtnetlink.c:3593 rtnetlink_rcv_msg+0x7c9/0xea0 net/core/rtnetlink.c:6089 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1371 [inline] free_pcp_prepare+0x812/0x900 mm/page_alloc.c:1421 free_unref_page_prepare mm/page_alloc.c:3343 [inline] free_unref_page+0x7d/0x390 mm/page_alloc.c:3438 do_slab_free mm/slub.c:3524 [inline] ___cache_free+0x118/0x1a0 mm/slub.c:3543 qlist_free_all+0x2b/0x70 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x169/0x180 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:446 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:750 [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+0x199/0x2f0 mm/slub.c:3268 getname_flags+0xb8/0x4e0 fs/namei.c:139 user_path_at_empty+0x2a/0x1a0 fs/namei.c:2894 do_readlinkat+0x11b/0x3b0 fs/stat.c:456 __do_sys_readlink fs/stat.c:489 [inline] __se_sys_readlink fs/stat.c:486 [inline] __x64_sys_readlink+0x7b/0x90 fs/stat.c:486 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff88807ff3a400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807ff3a480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807ff3a500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807ff3a580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807ff3a600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================