================================================================== BUG: KASAN: use-after-free in notifier_call_chain+0x1ee/0x200 kernel/notifier.c:75 Read of size 8 at addr ffff88806e2485e8 by task syz-executor.1/20623 CPU: 1 PID: 20623 Comm: syz-executor.1 Not tainted 6.0.0-rc6-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 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/0x6e9 mm/kasan/report.c:433 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495 notifier_call_chain+0x1ee/0x200 kernel/notifier.c:75 call_netdevice_notifiers_info+0x86/0x130 net/core/dev.c:1942 call_netdevice_notifiers_extack net/core/dev.c:1983 [inline] call_netdevice_notifiers net/core/dev.c:1997 [inline] netdev_wait_allrefs_any net/core/dev.c:10250 [inline] netdev_run_todo+0xbc2/0x1100 net/core/dev.c:10364 tun_detach drivers/net/tun.c:704 [inline] tun_chr_close+0xe0/0x180 drivers/net/tun.c:3455 __fput+0x277/0x9d0 fs/file_table.c:320 task_work_run+0xdd/0x1a0 kernel/task_work.c:177 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0xad5/0x29b0 kernel/exit.c:795 do_group_exit+0xd2/0x2f0 kernel/exit.c:925 get_signal+0x238c/0x2610 kernel/signal.c:2857 arch_do_signal_or_restart+0x82/0x2300 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop kernel/entry/common.c:166 [inline] exit_to_user_mode_prepare+0x15f/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+0x63/0xcd RIP: 0033:0x7f4838689409 Code: Unable to access opcode bytes at RIP 0x7f48386893df. RSP: 002b:00007f48375fe168 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: fffffffffffffff4 RBX: 00007f483879bf80 RCX: 00007f4838689409 RDX: 0000000000000048 RSI: 0000000020000180 RDI: 0000000000000000 RBP: 00007f48386e4367 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffca23b57bf R14: 00007f48375fe300 R15: 0000000000022000 Allocated by task 11360: 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:437 [inline] __kasan_slab_alloc+0x85/0xb0 mm/kasan/common.c:470 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:727 [inline] slab_alloc mm/slab.c:3294 [inline] __kmem_cache_alloc_lru mm/slab.c:3471 [inline] kmem_cache_alloc+0x214/0x520 mm/slab.c:3491 kmem_cache_zalloc include/linux/slab.h:723 [inline] net_alloc net/core/net_namespace.c:404 [inline] copy_net_ns+0x125/0x760 net/core/net_namespace.c:459 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:227 ksys_unshare+0x445/0x920 kernel/fork.c:3184 __do_sys_unshare kernel/fork.c:3255 [inline] __se_sys_unshare kernel/fork.c:3253 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3253 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+0x63/0xcd Freed by task 10: 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:367 [inline] ____kasan_slab_free+0x13d/0x1a0 mm/kasan/common.c:329 kasan_slab_free include/linux/kasan.h:200 [inline] __cache_free mm/slab.c:3418 [inline] kmem_cache_free.part.0+0x10f/0x2e0 mm/slab.c:3725 net_free net/core/net_namespace.c:433 [inline] net_free net/core/net_namespace.c:429 [inline] cleanup_net+0x8ba/0xb00 net/core/net_namespace.c:616 process_one_work+0x991/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0x7e/0x90 mm/kasan/generic.c:348 insert_work+0x48/0x350 kernel/workqueue.c:1358 __queue_work+0x625/0x1210 kernel/workqueue.c:1517 call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1514 [inline] __run_timers.part.0+0x4a3/0xa80 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0x152/0x1d0 kernel/time/timer.c:1805 __do_softirq+0x1d3/0x9c6 kernel/softirq.c:571 Second to last potentially related work creation: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 __kasan_record_aux_stack+0x7e/0x90 mm/kasan/generic.c:348 insert_work+0x48/0x350 kernel/workqueue.c:1358 __queue_work+0x625/0x1210 kernel/workqueue.c:1517 call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1514 [inline] __run_timers.part.0+0x4a3/0xa80 kernel/time/timer.c:1790 __run_timers kernel/time/timer.c:1768 [inline] run_timer_softirq+0x152/0x1d0 kernel/time/timer.c:1805 __do_softirq+0x1d3/0x9c6 kernel/softirq.c:571 The buggy address belongs to the object at ffff88806e248380 which belongs to the cache net_namespace of size 6784 The buggy address is located 616 bytes inside of 6784-byte region [ffff88806e248380, ffff88806e249e00) The buggy address belongs to the physical page: page:ffffea0001b89200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6e248 head:ffffea0001b89200 order:1 compound_mapcount:0 compound_pincount:0 memcg:ffff888074b9cf81 flags: 0x4fff00000010200(slab|head|node=1|zone=1|lastcpupid=0x7ff) raw: 04fff00000010200 ffffea0001b55408 ffff888040075d50 ffff8880121e1400 raw: 0000000000000000 ffff88806e248380 0000000100000001 ffff888074b9cf81 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0x140cc0(GFP_USER|__GFP_COMP), pid 9501, tgid 9500 (syz-executor.1), ts 365532547902, free_ts 364791527435 prep_new_page mm/page_alloc.c:2532 [inline] get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5515 __alloc_pages_node include/linux/gfp.h:243 [inline] kmem_getpages mm/slab.c:1363 [inline] cache_grow_begin+0x75/0x360 mm/slab.c:2569 fallback_alloc+0x1e2/0x2d0 mm/slab.c:3112 __do_cache_alloc mm/slab.c:3253 [inline] slab_alloc mm/slab.c:3287 [inline] __kmem_cache_alloc_lru mm/slab.c:3471 [inline] kmem_cache_alloc+0x30d/0x520 mm/slab.c:3491 kmem_cache_zalloc include/linux/slab.h:723 [inline] net_alloc net/core/net_namespace.c:404 [inline] copy_net_ns+0x125/0x760 net/core/net_namespace.c:459 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:227 ksys_unshare+0x445/0x920 kernel/fork.c:3184 __do_sys_unshare kernel/fork.c:3255 [inline] __se_sys_unshare kernel/fork.c:3253 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3253 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+0x63/0xcd page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1449 [inline] free_pcp_prepare+0x5e4/0xd20 mm/page_alloc.c:1499 free_unref_page_prepare mm/page_alloc.c:3380 [inline] free_unref_page+0x19/0x4d0 mm/page_alloc.c:3476 slab_destroy mm/slab.c:1615 [inline] slabs_destroy+0x89/0xc0 mm/slab.c:1635 __cache_free_alien mm/slab.c:774 [inline] cache_free_alien mm/slab.c:790 [inline] ___cache_free+0x200/0x3d0 mm/slab.c:3445 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x4f/0x1b0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x97/0xb0 mm/kasan/common.c:447 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:727 [inline] slab_alloc mm/slab.c:3294 [inline] kmem_cache_alloc_trace+0x212/0x460 mm/slab.c:3557 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] ref_tracker_alloc+0x152/0x560 lib/ref_tracker.c:85 __netdev_tracker_alloc include/linux/netdevice.h:3974 [inline] netdev_hold include/linux/netdevice.h:4003 [inline] netdev_hold include/linux/netdevice.h:3998 [inline] netdev_queue_add_kobject net/core/net-sysfs.c:1663 [inline] netdev_queue_update_kobjects+0x1a7/0x4e0 net/core/net-sysfs.c:1718 register_queue_kobjects net/core/net-sysfs.c:1779 [inline] netdev_register_kobject+0x330/0x400 net/core/net-sysfs.c:2019 register_netdevice+0xe01/0x1680 net/core/dev.c:10070 __ip_tunnel_create+0x398/0x570 net/ipv4/ip_tunnel.c:267 ip_tunnel_init_net+0x2e8/0x9f0 net/ipv4/ip_tunnel.c:1073 ops_init+0xaf/0x470 net/core/net_namespace.c:135 setup_net+0x5d1/0xc50 net/core/net_namespace.c:326 Memory state around the buggy address: ffff88806e248480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806e248500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88806e248580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806e248600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806e248680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================