================================================================== BUG: KASAN: use-after-free in notifier_call_chain kernel/notifier.c:75 [inline] BUG: KASAN: use-after-free in raw_notifier_call_chain+0x3e/0x170 kernel/notifier.c:455 Read of size 8 at addr ffff888038039ea8 by task syz-executor.3/25219 CPU: 1 PID: 25219 Comm: syz-executor.3 Not tainted 6.1.0-rc5-syzkaller-00103-g81ac25651a62 #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+0x1e3/0x2cb lib/dump_stack.c:106 print_address_description+0x74/0x340 mm/kasan/report.c:284 print_report+0x107/0x220 mm/kasan/report.c:395 kasan_report+0x139/0x170 mm/kasan/report.c:495 notifier_call_chain kernel/notifier.c:75 [inline] raw_notifier_call_chain+0x3e/0x170 kernel/notifier.c:455 call_netdevice_notifiers_info net/core/dev.c:1942 [inline] 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:10237 [inline] netdev_run_todo+0x8ce/0x1090 net/core/dev.c:10351 tun_detach drivers/net/tun.c:704 [inline] tun_chr_close+0x11f/0x130 drivers/net/tun.c:3467 __fput+0x3ba/0x880 fs/file_table.c:320 task_work_run+0x243/0x300 kernel/task_work.c:179 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x664/0x2070 kernel/exit.c:820 do_group_exit+0x1fd/0x2b0 kernel/exit.c:950 get_signal+0x1743/0x1810 kernel/signal.c:2858 arch_do_signal_or_restart+0x8d/0x750 arch/x86/kernel/signal.c:869 exit_to_user_mode_loop+0x74/0x160 kernel/entry/common.c:168 exit_to_user_mode_prepare+0xad/0x110 kernel/entry/common.c:203 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x2e/0x60 kernel/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f97a52b0361 Code: Unable to access opcode bytes at 0x7f97a52b0337. RSP: 002b:00007f97a5f340b0 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007f97a53abf80 RCX: 00007f97a52b0361 RDX: 00007f97a5f340f0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f97a52e6ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007fffddff6aef R14: 00007f97a5f34300 R15: 0000000000022000 Allocated by task 3675: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x65/0x70 mm/kasan/common.c:325 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slab.h:737 [inline] slab_alloc_node mm/slub.c:3398 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x1cc/0x300 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:679 [inline] net_alloc net/core/net_namespace.c:410 [inline] copy_net_ns+0x13c/0x5b0 net/core/net_namespace.c:465 create_new_namespaces+0x4db/0x8e0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11e/0x180 kernel/nsproxy.c:226 ksys_unshare+0x57f/0xb30 kernel/fork.c:3188 __do_sys_unshare kernel/fork.c:3259 [inline] __se_sys_unshare kernel/fork.c:3257 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3257 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 25449: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4c/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:511 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook+0x12e/0x1a0 mm/slub.c:1750 slab_free mm/slub.c:3661 [inline] kmem_cache_free+0x94/0x1d0 mm/slub.c:3683 net_free net/core/net_namespace.c:439 [inline] cleanup_net+0xb8b/0xc50 net/core/net_namespace.c:622 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 arch/x86/entry/entry_64.S:306 Last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:481 insert_work+0x54/0x3e0 kernel/workqueue.c:1358 __queue_work+0xaaa/0xd60 kernel/workqueue.c:1517 call_timer_fn+0xf5/0x210 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1514 [inline] __run_timers+0x7a2/0x980 kernel/time/timer.c:1790 __do_softirq+0x277/0x75b kernel/softirq.c:571 Second to last potentially related work creation: kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb0/0xc0 mm/kasan/generic.c:481 insert_work+0x54/0x3e0 kernel/workqueue.c:1358 __queue_work+0xaaa/0xd60 kernel/workqueue.c:1517 call_timer_fn+0xf5/0x210 kernel/time/timer.c:1474 expire_timers kernel/time/timer.c:1514 [inline] __run_timers+0x7a2/0x980 kernel/time/timer.c:1790 __do_softirq+0x277/0x75b kernel/softirq.c:571 The buggy address belongs to the object at ffff888038039c40 which belongs to the cache net_namespace of size 6976 The buggy address is located 616 bytes inside of 6976-byte region [ffff888038039c40, ffff88803803b780) The buggy address belongs to the physical page: page:ffffea0000e00e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88803803b880 pfn:0x38038 head:ffffea0000e00e00 order:3 compound_mapcount:0 compound_pincount:0 memcg:ffff88802851cd81 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0002017400 dead000000000002 ffff888140005640 raw: ffff88803803b880 0000000080040003 00000001ffffffff ffff88802851cd81 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3662, tgid 3662 (syz-executor.0), ts 142949040146, free_ts 0 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x72b/0x7a0 mm/page_alloc.c:4288 __alloc_pages+0x259/0x560 mm/page_alloc.c:5555 alloc_slab_page+0x70/0xf0 mm/slub.c:1794 allocate_slab+0x5e/0x4b0 mm/slub.c:1939 new_slab mm/slub.c:1992 [inline] ___slab_alloc+0x7f4/0xeb0 mm/slub.c:3180 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x24c/0x300 mm/slub.c:3422 kmem_cache_zalloc include/linux/slab.h:679 [inline] net_alloc net/core/net_namespace.c:410 [inline] copy_net_ns+0x13c/0x5b0 net/core/net_namespace.c:465 create_new_namespaces+0x4db/0x8e0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11e/0x180 kernel/nsproxy.c:226 ksys_unshare+0x57f/0xb30 kernel/fork.c:3188 __do_sys_unshare kernel/fork.c:3259 [inline] __se_sys_unshare kernel/fork.c:3257 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3257 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 page_owner free stack trace missing Memory state around the buggy address: ffff888038039d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888038039e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888038039e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888038039f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888038039f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================