================================================================== BUG: KASAN: use-after-free in notifier_call_chain+0x1ee/0x200 kernel/notifier.c:72 Read of size 8 at addr ffff888076e29de8 by task syz-executor.5/3633 CPU: 1 PID: 3633 Comm: syz-executor.5 Not tainted 5.17.0-rc6-syzkaller-01956-g57d29a2935c9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description.constprop.0.cold+0x8d/0x336 mm/kasan/report.c:255 __kasan_report mm/kasan/report.c:442 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:459 notifier_call_chain+0x1ee/0x200 kernel/notifier.c:72 call_netdevice_notifiers_info+0x86/0x130 net/core/dev.c:1937 call_netdevice_notifiers_extack net/core/dev.c:1978 [inline] call_netdevice_notifiers net/core/dev.c:1992 [inline] netdev_wait_allrefs_any net/core/dev.c:10119 [inline] netdev_run_todo+0xb90/0x10b0 net/core/dev.c:10231 tun_detach drivers/net/tun.c:696 [inline] tun_chr_close+0xe0/0x180 drivers/net/tun.c:3445 __fput+0x286/0x9f0 fs/file_table.c:317 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:32 [inline] do_exit+0xb29/0x2a30 kernel/exit.c:806 do_group_exit+0xd2/0x2f0 kernel/exit.c:935 __do_sys_exit_group kernel/exit.c:946 [inline] __se_sys_exit_group kernel/exit.c:944 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:944 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+0x44/0xae RIP: 0033:0x7f60abcc5049 Code: Unable to access opcode bytes at RIP 0x7f60abcc501f. RSP: 002b:00007fff04640a18 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fff04640bc0 RCX: 00007f60abcc5049 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000043 RBP: 0000000000000000 R08: 0000000000000025 R09: 00007fff04640bc0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f60abd1f05e R13: 000000000000001c R14: 0000000000000002 R15: 00007fff04640c00 Allocated by task 3633: 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_slab_alloc+0x90/0xc0 mm/kasan/common.c:469 kasan_slab_alloc include/linux/kasan.h:260 [inline] slab_post_alloc_hook mm/slab.h:732 [inline] slab_alloc_node mm/slub.c:3230 [inline] slab_alloc mm/slub.c:3238 [inline] kmem_cache_alloc+0x271/0x4b0 mm/slub.c:3243 kmem_cache_zalloc include/linux/slab.h:704 [inline] net_alloc net/core/net_namespace.c:403 [inline] copy_net_ns+0x125/0x760 net/core/net_namespace.c:458 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3058 __do_sys_unshare kernel/fork.c:3129 [inline] __se_sys_unshare kernel/fork.c:3127 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3127 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+0x44/0xae Freed by task 44: 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+0x126/0x160 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:236 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1754 slab_free mm/slub.c:3509 [inline] kmem_cache_free+0xd7/0x370 mm/slub.c:3526 net_free net/core/net_namespace.c:432 [inline] net_free net/core/net_namespace.c:428 [inline] cleanup_net+0x8ba/0xb00 net/core/net_namespace.c:615 process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307 worker_thread+0x657/0x1110 kernel/workqueue.c:2454 kthread+0x2e9/0x3a0 kernel/kthread.c:377 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 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 insert_work+0x48/0x370 kernel/workqueue.c:1368 __queue_work+0x5ca/0xf30 kernel/workqueue.c:1534 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1461 [inline] __run_timers.part.0+0x4a6/0xa30 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0x152/0x1d0 kernel/time/timer.c:1749 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 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 insert_work+0x48/0x370 kernel/workqueue.c:1368 __queue_work+0x5ca/0xf30 kernel/workqueue.c:1534 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421 expire_timers kernel/time/timer.c:1461 [inline] __run_timers.part.0+0x4a6/0xa30 kernel/time/timer.c:1734 __run_timers kernel/time/timer.c:1715 [inline] run_timer_softirq+0x152/0x1d0 kernel/time/timer.c:1749 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 The buggy address belongs to the object at ffff888076e29b80 which belongs to the cache net_namespace of size 6784 The buggy address is located 616 bytes inside of 6784-byte region [ffff888076e29b80, ffff888076e2b600) The buggy address belongs to the page: page:ffffea0001db8a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x76e28 head:ffffea0001db8a00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888010dd33c0 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 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 3630, ts 103851981221, free_ts 100008524002 prep_new_page mm/page_alloc.c:2434 [inline] get_page_from_freelist+0xa72/0x2f50 mm/page_alloc.c:4165 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5389 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2271 alloc_slab_page mm/slub.c:1799 [inline] allocate_slab+0x27f/0x3c0 mm/slub.c:1944 new_slab mm/slub.c:2004 [inline] ___slab_alloc+0xbe1/0x12b0 mm/slub.c:3018 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3105 slab_alloc_node mm/slub.c:3196 [inline] slab_alloc mm/slub.c:3238 [inline] kmem_cache_alloc+0x3cb/0x4b0 mm/slub.c:3243 kmem_cache_zalloc include/linux/slab.h:704 [inline] net_alloc net/core/net_namespace.c:403 [inline] copy_net_ns+0x125/0x760 net/core/net_namespace.c:458 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x445/0x920 kernel/fork.c:3058 __do_sys_unshare kernel/fork.c:3129 [inline] __se_sys_unshare kernel/fork.c:3127 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3127 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+0x44/0xae page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1352 [inline] free_pcp_prepare+0x374/0x870 mm/page_alloc.c:1404 free_unref_page_prepare mm/page_alloc.c:3325 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3404 __unfreeze_partials+0x320/0x340 mm/slub.c:2536 qlink_free mm/kasan/quarantine.c:157 [inline] qlist_free_all+0x6d/0x160 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0xa2/0xc0 mm/kasan/common.c:446 kasan_slab_alloc include/linux/kasan.h:260 [inline] slab_post_alloc_hook mm/slab.h:732 [inline] slab_alloc_node mm/slub.c:3230 [inline] kmem_cache_alloc_node+0x2c3/0x4f0 mm/slub.c:3266 __alloc_skb+0x215/0x340 net/core/skbuff.c:414 alloc_skb_fclone include/linux/skbuff.h:1349 [inline] tcp_stream_alloc_skb+0x66/0x910 net/ipv4/tcp.c:862 tcp_sendmsg_locked+0xac8/0x2e20 net/ipv4/tcp.c:1297 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1448 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 sock_write_iter+0x289/0x3c0 net/socket.c:1061 call_write_iter include/linux/fs.h:2074 [inline] new_sync_write+0x431/0x660 fs/read_write.c:503 vfs_write+0x7cd/0xae0 fs/read_write.c:590 Memory state around the buggy address: ffff888076e29c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888076e29d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888076e29d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888076e29e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888076e29e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================