================================================================== BUG: KASAN: use-after-free in __fib6_clean_all+0x296/0x2a0 net/ipv6/ip6_fib.c:2255 Read of size 8 at addr ffff88801ad82000 by task syz-executor.4/23107 CPU: 1 PID: 23107 Comm: syz-executor.4 Not tainted 5.18.0-rc7-syzkaller-00116-geb4c07889647 #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+0xeb/0x495 mm/kasan/report.c:313 print_report mm/kasan/report.c:429 [inline] kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491 __fib6_clean_all+0x296/0x2a0 net/ipv6/ip6_fib.c:2255 rt6_sync_down_dev net/ipv6/route.c:4883 [inline] rt6_disable_ip+0x7b7/0x9a0 net/ipv6/route.c:4888 addrconf_ifdown.isra.0+0xf6/0x16b0 net/ipv6/addrconf.c:3738 addrconf_notify+0xeb/0x1ba0 net/ipv6/addrconf.c:3662 notifier_call_chain+0xb5/0x200 kernel/notifier.c:84 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1938 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:10141 [inline] netdev_run_todo+0xb90/0x10b0 net/core/dev.c:10253 tun_detach drivers/net/tun.c:696 [inline] tun_chr_close+0xe0/0x180 drivers/net/tun.c:3445 __fput+0x277/0x9d0 fs/file_table.c:317 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 exit_task_work include/linux/task_work.h:37 [inline] do_exit+0xaff/0x2a00 kernel/exit.c:795 do_group_exit+0xd2/0x2f0 kernel/exit.c:925 get_signal+0x22df/0x24c0 kernel/signal.c:2864 arch_do_signal_or_restart+0x82/0x20f0 arch/x86/kernel/signal.c:867 exit_to_user_mode_loop kernel/entry/common.c:166 [inline] exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:201 irqentry_exit_to_user_mode+0x5/0x40 kernel/entry/common.c:307 exc_page_fault+0xc6/0x180 arch/x86/mm/fault.c:1543 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0033:0x7f6718a37ef6 Code: Unable to access opcode bytes at RIP 0x7f6718a37ecc. RSP: 002b:00007ffd1a006188 EFLAGS: 00010246 RAX: 000055555575c6c0 RBX: 0000000000000001 RCX: 00007f6719ad53c0 RDX: 00007f6719ad53c0 RSI: 00007f6718b6eef0 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000000 R09: 00007f6718b6eef0 R10: 000055555575c400 R11: 0000000000000202 R12: 0000000000000001 R13: 0000000000000001 R14: 0000000000000001 R15: 00007ffd1a0062a0 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_kmalloc mm/kasan/common.c:515 [inline] ____kasan_kmalloc mm/kasan/common.c:474 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:524 kmalloc include/linux/slab.h:581 [inline] kzalloc include/linux/slab.h:714 [inline] fib6_net_init net/ipv6/ip6_fib.c:2376 [inline] fib6_net_init+0x1d7/0xa20 net/ipv6/ip6_fib.c:2351 ops_init+0xaf/0x470 net/core/net_namespace.c:134 setup_net+0x5d1/0xc50 net/core/net_namespace.c:325 copy_net_ns+0x318/0x760 net/core/net_namespace.c:471 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:3132 __do_sys_unshare kernel/fork.c:3203 [inline] __se_sys_unshare kernel/fork.c:3201 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3201 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 6047: 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+0x166/0x1a0 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1754 slab_free mm/slub.c:3510 [inline] kfree+0xd6/0x4d0 mm/slub.c:4552 fib6_net_exit+0x1c9/0x280 net/ipv6/ip6_fib.c:2438 ops_exit_list+0xb0/0x170 net/core/net_namespace.c:162 cleanup_net+0x4ea/0xb00 net/core/net_namespace.c:594 process_one_work+0x996/0x1610 kernel/workqueue.c:2289 worker_thread+0x665/0x1080 kernel/workqueue.c:2436 kthread+0x2e9/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298 The buggy address belongs to the object at ffff88801ad82000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 0 bytes inside of 2048-byte region [ffff88801ad82000, ffff88801ad82800) The buggy address belongs to the physical page: page:ffffea00006b6000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1ad80 head:ffffea00006b6000 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888010c42000 raw: 0000000000000000 0000000000080008 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.4), ts 103628772563, free_ts 99253319102 prep_new_page mm/page_alloc.c:2441 [inline] get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4182 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5408 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2272 alloc_slab_page mm/slub.c:1799 [inline] allocate_slab+0x26c/0x3c0 mm/slub.c:1944 new_slab mm/slub.c:2004 [inline] ___slab_alloc+0x8df/0xf20 mm/slub.c:3005 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3092 slab_alloc_node mm/slub.c:3183 [inline] slab_alloc mm/slub.c:3225 [inline] __kmalloc_track_caller+0x2e7/0x320 mm/slub.c:4916 kmemdup+0x23/0x50 mm/util.c:128 kmemdup include/linux/fortify-string.h:440 [inline] ip_vs_control_net_init_sysctl net/netfilter/ipvs/ip_vs_ctl.c:4040 [inline] ip_vs_control_net_init+0x525/0x1660 net/netfilter/ipvs/ip_vs_ctl.c:4194 __ip_vs_init+0x21b/0x4d0 net/netfilter/ipvs/ip_vs_core.c:2310 ops_init+0xaf/0x470 net/core/net_namespace.c:134 setup_net+0x5d1/0xc50 net/core/net_namespace.c:325 copy_net_ns+0x318/0x760 net/core/net_namespace.c:471 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:3132 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1356 [inline] free_pcp_prepare+0x549/0xd20 mm/page_alloc.c:1406 free_unref_page_prepare mm/page_alloc.c:3328 [inline] free_unref_page+0x19/0x6a0 mm/page_alloc.c:3423 skb_free_frag include/linux/skbuff.h:3135 [inline] skb_free_head+0x96/0x110 net/core/skbuff.c:653 skb_release_data+0x67a/0x810 net/core/skbuff.c:677 skb_release_all net/core/skbuff.c:742 [inline] __kfree_skb+0x46/0x60 net/core/skbuff.c:756 __sk_defer_free_flush net/ipv4/tcp.c:1601 [inline] sk_defer_free_flush include/net/tcp.h:1388 [inline] tcp_recvmsg+0x1ca/0x610 net/ipv4/tcp.c:2577 inet_recvmsg+0x11b/0x5e0 net/ipv4/af_inet.c:850 sock_recvmsg_nosec net/socket.c:948 [inline] sock_recvmsg net/socket.c:966 [inline] sock_recvmsg net/socket.c:962 [inline] sock_read_iter+0x336/0x470 net/socket.c:1039 call_read_iter include/linux/fs.h:2044 [inline] new_sync_read+0x4f9/0x5f0 fs/read_write.c:401 vfs_read+0x492/0x5d0 fs/read_write.c:482 ksys_read+0x1e8/0x250 fs/read_write.c:620 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: ffff88801ad81f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801ad81f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88801ad82000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801ad82080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801ad82100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================