================================================================== BUG: KASAN: use-after-free in vlan_dev_get_iflink+0x5f/0x70 net/8021q/vlan_dev.c:769 Read of size 4 at addr ffff888053fdcb08 by task syz-executor.1/24969 CPU: 0 PID: 24969 Comm: syz-executor.1 Not tainted 4.14.177-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x13e/0x194 lib/dump_stack.c:58 print_address_description.cold+0x7c/0x1e2 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report mm/kasan/report.c:409 [inline] kasan_report.cold+0xa9/0x2ae mm/kasan/report.c:393 vlan_dev_get_iflink+0x5f/0x70 net/8021q/vlan_dev.c:769 dev_get_iflink+0x73/0xe0 net/core/dev.c:690 rfc2863_policy+0x17e/0x1e0 net/core/link_watch.c:43 linkwatch_do_dev+0x16/0xe0 net/core/link_watch.c:157 linkwatch_forget_dev+0x15c/0x1f0 net/core/link_watch.c:223 netdev_wait_allrefs net/core/dev.c:7832 [inline] netdev_run_todo+0x234/0x710 net/core/dev.c:7933 rtnl_unlock net/core/rtnetlink.c:106 [inline] rtnetlink_rcv_msg+0x3cb/0xb10 net/core/rtnetlink.c:4317 netlink_rcv_skb+0x127/0x370 net/netlink/af_netlink.c:2433 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline] netlink_unicast+0x437/0x620 net/netlink/af_netlink.c:1313 netlink_sendmsg+0x733/0xbe0 net/netlink/af_netlink.c:1878 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xc5/0x100 net/socket.c:656 ___sys_sendmsg+0x70a/0x840 net/socket.c:2062 __sys_sendmsg+0xa3/0x120 net/socket.c:2096 SYSC_sendmsg net/socket.c:2107 [inline] SyS_sendmsg+0x27/0x40 net/socket.c:2103 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45c829 RSP: 002b:00007f28aaecfc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000500a40 RCX: 000000000045c829 RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000006 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000009fe R14: 00000000004ccb57 R15: 00007f28aaed06d4 Allocated by task 24943: save_stack+0x32/0xa0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc mm/kasan/kasan.c:551 [inline] kasan_kmalloc+0xbf/0xe0 mm/kasan/kasan.c:529 __do_kmalloc_node mm/slab.c:3682 [inline] __kmalloc_node+0x4c/0x70 mm/slab.c:3689 kmalloc_node include/linux/slab.h:530 [inline] kvmalloc_node+0x46/0xd0 mm/util.c:397 kvmalloc include/linux/mm.h:531 [inline] kvzalloc include/linux/mm.h:539 [inline] alloc_netdev_mqs+0x76/0xb70 net/core/dev.c:8098 rtnl_create_link+0x1ab/0x880 net/core/rtnetlink.c:2460 rtnl_newlink+0xdd0/0x1720 net/core/rtnetlink.c:2718 rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4315 netlink_rcv_skb+0x127/0x370 net/netlink/af_netlink.c:2433 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline] netlink_unicast+0x437/0x620 net/netlink/af_netlink.c:1313 netlink_sendmsg+0x733/0xbe0 net/netlink/af_netlink.c:1878 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xc5/0x100 net/socket.c:656 ___sys_sendmsg+0x70a/0x840 net/socket.c:2062 __sys_sendmsg+0xa3/0x120 net/socket.c:2096 SYSC_sendmsg net/socket.c:2107 [inline] SyS_sendmsg+0x27/0x40 net/socket.c:2103 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 Freed by task 24985: save_stack+0x32/0xa0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xcb/0x260 mm/slab.c:3815 kvfree+0x45/0x50 mm/util.c:416 device_release+0x15f/0x1a0 drivers/base/core.c:833 kobject_cleanup lib/kobject.c:646 [inline] kobject_release lib/kobject.c:675 [inline] kref_put include/linux/kref.h:70 [inline] kobject_put+0x13e/0x1f0 lib/kobject.c:692 netdev_run_todo+0x4a9/0x710 net/core/dev.c:7955 rtnl_unlock net/core/rtnetlink.c:106 [inline] rtnetlink_rcv_msg+0x3cb/0xb10 net/core/rtnetlink.c:4317 netlink_rcv_skb+0x127/0x370 net/netlink/af_netlink.c:2433 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline] netlink_unicast+0x437/0x620 net/netlink/af_netlink.c:1313 netlink_sendmsg+0x733/0xbe0 net/netlink/af_netlink.c:1878 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xc5/0x100 net/socket.c:656 ___sys_sendmsg+0x70a/0x840 net/socket.c:2062 __sys_sendmsg+0xa3/0x120 net/socket.c:2096 SYSC_sendmsg net/socket.c:2107 [inline] SyS_sendmsg+0x27/0x40 net/socket.c:2103 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 The buggy address belongs to the object at ffff888053fdca00 which belongs to the cache kmalloc-4096 of size 4096 The buggy address is located 264 bytes inside of 4096-byte region [ffff888053fdca00, ffff888053fdda00) The buggy address belongs to the page: page:ffffea00014ff700 count:1 mapcount:0 mapping:ffff888053fdca00 index:0x0 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffff888053fdca00 0000000000000000 0000000100000001 raw: ffffea00014d7620 ffffea00014a7ba0 ffff88812fe54dc0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888053fdca00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888053fdca80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888053fdcb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888053fdcb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888053fdcc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================