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BUG: KASAN: use-after-free in notifier_call_chain+0x1ee/0x200 kernel/notifier.c:72
Read of size 8 at addr ffff8880776e54e8 by task syz-executor.0/3626

CPU: 0 PID: 3626 Comm: syz-executor.0 Not tainted 5.17.0-rc8-syzkaller-02628-g351bdbb6419c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __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:1935
 call_netdevice_notifiers_extack net/core/dev.c:1976 [inline]
 call_netdevice_notifiers net/core/dev.c:1990 [inline]
 netdev_wait_allrefs_any net/core/dev.c:10131 [inline]
 netdev_run_todo+0xb90/0x10b0 net/core/dev.c:10243
 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: 0033:0x7fbf0e921049
Code: Unable to access opcode bytes at RIP 0x7fbf0e92101f.
RSP: 002b:00007ffd2d87b188 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007ffd2d87b330 RCX: 00007fbf0e921049
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000043
RBP: 0000000000000000 R08: 0000000000000025 R09: 00007ffd2d87b330
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fbf0e97b05e
R13: 000000000000001c R14: 0000000000000004 R15: 00007ffd2d87b370
 </TASK>

Allocated by task 3626:
 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 3737:
 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

The buggy address belongs to the object at ffff8880776e5280
 which belongs to the cache net_namespace of size 6784
The buggy address is located 616 bytes inside of
 6784-byte region [ffff8880776e5280, ffff8880776e6d00)
The buggy address belongs to the page:
page:ffffea0001ddb800 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880776e1b80 pfn:0x776e0
head:ffffea0001ddb800 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000001 ffff8881400043c0
raw: ffff8880776e1b80 0000000080040002 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 3629, ts 177508973606, free_ts 177241320167
 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 include/linux/skbuff.h:1300 [inline]
 bt_skb_alloc include/net/bluetooth/bluetooth.h:424 [inline]
 vhci_get_user drivers/bluetooth/hci_vhci.c:391 [inline]
 vhci_write+0xbd/0x460 drivers/bluetooth/hci_vhci.c:511
 call_write_iter include/linux/fs.h:2074 [inline]
 do_iter_readv_writev+0x47a/0x750 fs/read_write.c:725
 do_iter_write+0x188/0x710 fs/read_write.c:851
 vfs_writev+0x1aa/0x630 fs/read_write.c:924
 do_writev+0x139/0x300 fs/read_write.c:967
 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

Memory state around the buggy address:
 ffff8880776e5380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880776e5400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880776e5480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                          ^
 ffff8880776e5500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880776e5580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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