================================================================== BUG: KASAN: use-after-free in nexthop_flush_dev+0x20b/0x230 net/ipv4/nexthop.c:2381 Read of size 8 at addr ffff888024b68058 by task syz-executor.0/25176 CPU: 1 PID: 25176 Comm: syz-executor.0 Not tainted 5.18.0-rc3-next-20220420-syzkaller #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 nexthop_flush_dev+0x20b/0x230 net/ipv4/nexthop.c:2381 nh_netdev_event+0x2c6/0x370 net/ipv4/nexthop.c:3574 notifier_call_chain+0xb5/0x200 kernel/notifier.c:84 call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:1943 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:10165 [inline] netdev_run_todo+0xb90/0x10b0 net/core/dev.c:10277 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:796 do_group_exit+0xd2/0x2f0 kernel/exit.c:926 __do_sys_exit_group kernel/exit.c:937 [inline] __se_sys_exit_group kernel/exit.c:935 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:935 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: 0033:0x7f64116890e9 Code: Unable to access opcode bytes at RIP 0x7f64116890bf. RSP: 002b:00007ffebf147a08 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007ffebf147bb0 RCX: 00007f64116890e9 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000043 RBP: 0000000000000000 R08: 0000000000000025 R09: 00007ffebf147bb0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f64116e305e R13: 000000000000001c R14: 0000000000000002 R15: 00007ffebf147bf0 Allocated by task 25176: 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:588 [inline] kzalloc include/linux/slab.h:721 [inline] nexthop_net_init+0x71/0x140 net/ipv4/nexthop.c:3753 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:3139 __do_sys_unshare kernel/fork.c:3210 [inline] __se_sys_unshare kernel/fork.c:3208 [inline] __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3208 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 11191: 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:1729 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1755 slab_free mm/slub.c:3509 [inline] kfree+0xd6/0x4d0 mm/slub.c:4559 nexthop_net_exit_batch+0x245/0x2d0 net/ipv4/nexthop.c:3743 ops_exit_list+0x125/0x170 net/core/net_namespace.c:167 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 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 call_rcu+0x99/0x790 kernel/rcu/tree.c:3206 netlink_release+0xf08/0x1db0 net/netlink/af_netlink.c:815 __sock_release+0xcd/0x280 net/socket.c:650 sock_close+0x18/0x20 net/socket.c:1318 __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:796 do_group_exit+0xd2/0x2f0 kernel/exit.c:926 get_signal+0x22df/0x24c0 kernel/signal.c:2864 arch_do_signal_or_restart+0x82/0x20f0 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:291 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 call_rcu+0x99/0x790 kernel/rcu/tree.c:3206 keypair_free_kref drivers/net/wireguard/noise.c:128 [inline] kref_put include/linux/kref.h:65 [inline] wg_noise_keypair_put+0x133/0x370 drivers/net/wireguard/noise.c:139 add_new_keypair drivers/net/wireguard/noise.c:237 [inline] wg_noise_handshake_begin_session+0x65f/0xe20 drivers/net/wireguard/noise.c:845 wg_receive_handshake_packet+0x3c4/0x9c0 drivers/net/wireguard/receive.c:183 wg_packet_handshake_receive_worker+0x16f/0x390 drivers/net/wireguard/receive.c:220 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 ffff888024b68000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 88 bytes inside of 2048-byte region [ffff888024b68000, ffff888024b68800) The buggy address belongs to the physical page: page:ffffea000092da00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x24b68 head:ffffea000092da00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0000839e00 dead000000000002 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 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 3621, tgid 3621 (syz-executor.3), ts 154920554054, free_ts 0 prep_new_page mm/page_alloc.c:2394 [inline] get_page_from_freelist+0xba2/0x3e00 mm/page_alloc.c:4144 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5365 alloc_pages+0x1aa/0x310 mm/mempolicy.c:2279 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+0x985/0xd90 mm/slub.c:3004 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3091 slab_alloc_node mm/slub.c:3182 [inline] __kmalloc_node_track_caller+0x2cb/0x360 mm/slub.c:4954 kmalloc_reserve net/core/skbuff.c:354 [inline] pskb_expand_head+0x15e/0x1070 net/core/skbuff.c:1700 netlink_trim+0x1ea/0x240 net/netlink/af_netlink.c:1301 netlink_broadcast+0x5b/0xd60 net/netlink/af_netlink.c:1497 nlmsg_multicast include/net/netlink.h:1033 [inline] nlmsg_notify+0x8f/0x280 net/netlink/af_netlink.c:2545 rtnl_notify net/core/rtnetlink.c:767 [inline] rtmsg_ifinfo_send net/core/rtnetlink.c:3904 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:3919 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:3907 [inline] rtmsg_ifinfo+0xf0/0x120 net/core/rtnetlink.c:3925 __dev_notify_flags+0x226/0x2b0 net/core/dev.c:8497 rtnl_configure_link+0x16b/0x240 net/core/rtnetlink.c:3193 __rtnl_newlink+0x100b/0x16a0 net/core/rtnetlink.c:3529 rtnl_newlink+0x64/0xa0 net/core/rtnetlink.c:3569 page_owner free stack trace missing Memory state around the buggy address: ffff888024b67f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888024b67f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888024b68000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888024b68080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888024b68100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================