================================================================== BUG: KASAN: use-after-free in notifier_call_chain+0x1ee/0x200 kernel/notifier.c:75 Read of size 8 at addr ffff8880749bc368 by task syz-executor.3/14873 CPU: 3 PID: 14873 Comm: syz-executor.3 Not tainted 6.0.0-rc6-syzkaller-00045-gdc164f4fb00a #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 ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:299 RIP: 0033:0x7fd2a208a649 Code: Unable to access opcode bytes at RIP 0x7fd2a208a61f. RSP: 002b:00007fd2a31c8118 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: 0000000000000000 RBX: 00007fd2a219bf80 RCX: 00007fd2a208a649 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fd2a20e5560 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe9fa0a93f R14: 00007fd2a31c8300 R15: 0000000000022000 Allocated by task 3792: 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:226 ksys_unshare+0x445/0x920 kernel/fork.c:3181 __do_sys_unshare kernel/fork.c:3252 [inline] __se_sys_unshare kernel/fork.c:3250 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3250 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 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 ffff8880749bc100 which belongs to the cache net_namespace of size 6784 The buggy address is located 616 bytes inside of 6784-byte region [ffff8880749bc100, ffff8880749bdb80) The buggy address belongs to the physical page: page:ffffea0001d26f00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x749bc head:ffffea0001d26f00 order:1 compound_mapcount:0 compound_pincount:0 memcg:ffff8880735fc541 flags: 0x4fff00000010200(slab|head|node=1|zone=1|lastcpupid=0x7ff) raw: 04fff00000010200 ffff888040075d50 ffffea0001d20d08 ffff8880121e1400 raw: 0000000000000000 ffff8880749bc100 0000000100000001 ffff8880735fc541 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 3792, tgid 3792 (syz-executor.3), ts 208576777776, free_ts 208570073130 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:226 ksys_unshare+0x445/0x920 kernel/fork.c:3181 __do_sys_unshare kernel/fork.c:3252 [inline] __se_sys_unshare kernel/fork.c:3250 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3250 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_node mm/slab.c:3232 [inline] kmem_cache_alloc_node+0x2f1/0x560 mm/slab.c:3583 __alloc_skb+0x210/0x2f0 net/core/skbuff.c:422 alloc_skb include/linux/skbuff.h:1257 [inline] nlmsg_new include/net/netlink.h:953 [inline] netlink_ack+0x1f0/0xa80 net/netlink/af_netlink.c:2436 netlink_rcv_skb+0x33d/0x420 net/netlink/af_netlink.c:2507 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x543/0x7f0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x917/0xe10 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:734 __sys_sendto+0x236/0x340 net/socket.c:2117 __do_sys_sendto net/socket.c:2129 [inline] __se_sys_sendto net/socket.c:2125 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2125 Memory state around the buggy address: ffff8880749bc200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880749bc280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880749bc300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880749bc380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880749bc400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================