================================================================== 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 ffff888021958268 by task syz-executor.0/3633 CPU: 1 PID: 3633 Comm: syz-executor.0 Not tainted 5.18.0-syzkaller-11439-g8ab2afa23bd1 #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+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 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:1940 [inline] call_netdevice_notifiers_extack net/core/dev.c:1981 [inline] call_netdevice_notifiers net/core/dev.c:1995 [inline] netdev_wait_allrefs_any net/core/dev.c:10225 [inline] netdev_run_todo+0x8ae/0x1070 net/core/dev.c:10337 tun_detach drivers/net/tun.c:695 [inline] tun_chr_close+0x11f/0x130 drivers/net/tun.c:3444 __fput+0x3b9/0x820 fs/file_table.c:317 task_work_run+0x146/0x1c0 kernel/task_work.c:177 exit_task_work include/linux/task_work.h:38 [inline] do_exit+0x547/0x1ed0 kernel/exit.c:795 do_group_exit+0x23b/0x2f0 kernel/exit.c:925 __do_sys_exit_group kernel/exit.c:936 [inline] __se_sys_exit_group kernel/exit.c:934 [inline] __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:934 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+0x46/0xb0 RIP: 0033:0x7f94abe89109 Code: Unable to access opcode bytes at RIP 0x7f94abe890df. RSP: 002b:00007fff143c5c18 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fff143c64a0 RCX: 00007f94abe89109 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000043 RBP: 0000000000000000 R08: 0000000000000024 R09: 00007fff143c64a0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f94abed27f0 R13: 0000000000000001 R14: 0000000000000002 R15: 00007fff143c64e0 Allocated by task 3633: 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_slab_alloc+0xb2/0xe0 mm/kasan/common.c:469 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:750 [inline] slab_alloc_node mm/slub.c:3214 [inline] slab_alloc mm/slub.c:3222 [inline] __kmem_cache_alloc_lru mm/slub.c:3229 [inline] kmem_cache_alloc+0x199/0x2f0 mm/slub.c:3239 kmem_cache_zalloc include/linux/slab.h:723 [inline] net_alloc net/core/net_namespace.c:403 [inline] copy_net_ns+0x13c/0x5b0 net/core/net_namespace.c:458 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:3135 __do_sys_unshare kernel/fork.c:3206 [inline] __se_sys_unshare kernel/fork.c:3204 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3204 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+0x46/0xb0 Freed by task 18235: 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:1727 [inline] slab_free_freelist_hook+0x12e/0x1a0 mm/slub.c:1753 slab_free mm/slub.c:3507 [inline] kmem_cache_free+0xc7/0x270 mm/slub.c:3524 net_free net/core/net_namespace.c:432 [inline] cleanup_net+0xb8b/0xc50 net/core/net_namespace.c:615 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 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 insert_work+0x54/0x3e0 kernel/workqueue.c:1358 __queue_work+0x969/0xc20 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+0x382/0x793 kernel/softirq.c:571 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 insert_work+0x54/0x3e0 kernel/workqueue.c:1358 __queue_work+0x969/0xc20 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+0x382/0x793 kernel/softirq.c:571 The buggy address belongs to the object at ffff888021958000 which belongs to the cache net_namespace of size 6784 The buggy address is located 616 bytes inside of 6784-byte region [ffff888021958000, ffff888021959a80) The buggy address belongs to the physical page: page:ffffea0000865600 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88802195d280 pfn:0x21958 head:ffffea0000865600 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0000ba5408 ffff8880115ce348 ffff888140007500 raw: ffff88802195d280 0000000000040002 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 3633, tgid 3633 (syz-executor.0), ts 115047299725, free_ts 93649209123 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:1797 allocate_slab+0x5e/0x520 mm/slub.c:1942 new_slab mm/slub.c:2002 [inline] ___slab_alloc+0x41e/0xcd0 mm/slub.c:3002 __slab_alloc mm/slub.c:3089 [inline] slab_alloc_node mm/slub.c:3180 [inline] slab_alloc mm/slub.c:3222 [inline] __kmem_cache_alloc_lru mm/slub.c:3229 [inline] kmem_cache_alloc+0x246/0x2f0 mm/slub.c:3239 kmem_cache_zalloc include/linux/slab.h:723 [inline] net_alloc net/core/net_namespace.c:403 [inline] copy_net_ns+0x13c/0x5b0 net/core/net_namespace.c:458 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:3135 __do_sys_unshare kernel/fork.c:3206 [inline] __se_sys_unshare kernel/fork.c:3204 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3204 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+0x46/0xb0 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 free_slab mm/slub.c:2041 [inline] discard_slab mm/slub.c:2047 [inline] __unfreeze_partials+0x1ab/0x200 mm/slub.c:2521 put_cpu_partial+0x116/0x180 mm/slub.c:2597 do_slab_free mm/slub.c:3495 [inline] ___cache_free+0x118/0x1a0 mm/slub.c:3514 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:3214 [inline] kmem_cache_alloc_node+0x1cd/0x340 mm/slub.c:3264 __alloc_skb+0xd5/0x660 net/core/skbuff.c:414 alloc_skb_fclone include/linux/skbuff.h:1476 [inline] tcp_stream_alloc_skb+0x67/0x480 net/ipv4/tcp.c:862 tcp_sendmsg_locked+0xd64/0x3fc0 net/ipv4/tcp.c:1297 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1448 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] sock_write_iter+0x3e7/0x560 net/socket.c:1108 call_write_iter include/linux/fs.h:2060 [inline] new_sync_write fs/read_write.c:504 [inline] vfs_write+0xa22/0xd40 fs/read_write.c:591 ksys_write+0x19b/0x2c0 fs/read_write.c:644 Memory state around the buggy address: ffff888021958100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888021958180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888021958200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888021958280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888021958300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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