================================================================== BUG: KASAN: use-after-free in macvlan_dev_get_iflink+0x5f/0x70 drivers/net/macvlan.c:1099 Read of size 4 at addr ffff888018a0e4c8 by task syz-executor.2/20381 CPU: 1 PID: 20381 Comm: syz-executor.2 Not tainted 4.19.150-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x22c/0x33e lib/dump_stack.c:118 print_address_description.cold+0x56/0x25c mm/kasan/report.c:256 kasan_report_error.cold+0x66/0xb9 mm/kasan/report.c:354 kasan_report mm/kasan/report.c:412 [inline] __asan_report_load4_noabort+0x88/0x90 mm/kasan/report.c:432 macvlan_dev_get_iflink+0x5f/0x70 drivers/net/macvlan.c:1099 dev_get_iflink+0x73/0xe0 net/core/dev.c:692 default_operstate net/core/link_watch.c:43 [inline] rfc2863_policy+0x1af/0x200 net/core/link_watch.c:55 linkwatch_do_dev+0x1d/0x110 net/core/link_watch.c:157 linkwatch_forget_dev+0x16a/0x200 net/core/link_watch.c:223 netdev_wait_allrefs net/core/dev.c:8879 [inline] netdev_run_todo+0x258/0xc80 net/core/dev.c:8975 rtnl_unlock net/core/rtnetlink.c:117 [inline] rtnetlink_rcv_msg+0x4a5/0xc10 net/core/rtnetlink.c:4779 netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2455 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x717/0xcc0 net/netlink/af_netlink.c:1909 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xc7/0x130 net/socket.c:632 ___sys_sendmsg+0x7bb/0x8f0 net/socket.c:2115 __sys_sendmsg net/socket.c:2153 [inline] __do_sys_sendmsg net/socket.c:2162 [inline] __se_sys_sendmsg net/socket.c:2160 [inline] __x64_sys_sendmsg+0x132/0x220 net/socket.c:2160 do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45de29 Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fa35a91dc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000002e5c0 RCX: 000000000045de29 RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000006 RBP: 000000000118c008 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bfd4 R13: 00007ffd9ef12acf R14: 00007fa35a91e9c0 R15: 000000000118bfd4 Allocated by task 20373: __do_kmalloc_node mm/slab.c:3689 [inline] __kmalloc_node+0x4c/0x70 mm/slab.c:3696 kmalloc_node include/linux/slab.h:557 [inline] kvmalloc_node+0x61/0xf0 mm/util.c:423 kvmalloc include/linux/mm.h:577 [inline] kvzalloc include/linux/mm.h:585 [inline] alloc_netdev_mqs+0x97/0xd60 net/core/dev.c:9139 rtnl_create_link+0x1d4/0xa40 net/core/rtnetlink.c:2869 rtnl_newlink+0xf3c/0x15b0 net/core/rtnetlink.c:3131 rtnetlink_rcv_msg+0x498/0xc10 net/core/rtnetlink.c:4778 netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2455 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x717/0xcc0 net/netlink/af_netlink.c:1909 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xc7/0x130 net/socket.c:632 ___sys_sendmsg+0x7bb/0x8f0 net/socket.c:2115 __sys_sendmsg net/socket.c:2153 [inline] __do_sys_sendmsg net/socket.c:2162 [inline] __se_sys_sendmsg net/socket.c:2160 [inline] __x64_sys_sendmsg+0x132/0x220 net/socket.c:2160 do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 20373: __cache_free mm/slab.c:3503 [inline] kfree+0xcc/0x250 mm/slab.c:3822 kvfree+0x59/0x60 mm/util.c:452 device_release+0x76/0x210 drivers/base/core.c:1061 kobject_cleanup lib/kobject.c:662 [inline] kobject_release lib/kobject.c:691 [inline] kref_put include/linux/kref.h:70 [inline] kobject_put+0x22d/0x350 lib/kobject.c:708 netdev_run_todo+0x833/0xc80 net/core/dev.c:8998 rtnl_unlock net/core/rtnetlink.c:117 [inline] rtnetlink_rcv_msg+0x4a5/0xc10 net/core/rtnetlink.c:4779 netlink_rcv_skb+0x160/0x440 net/netlink/af_netlink.c:2455 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x4d5/0x690 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x717/0xcc0 net/netlink/af_netlink.c:1909 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xc7/0x130 net/socket.c:632 ___sys_sendmsg+0x7bb/0x8f0 net/socket.c:2115 __sys_sendmsg net/socket.c:2153 [inline] __do_sys_sendmsg net/socket.c:2162 [inline] __se_sys_sendmsg net/socket.c:2160 [inline] __x64_sys_sendmsg+0x132/0x220 net/socket.c:2160 do_syscall_64+0xf9/0x670 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff888018a0e3c0 which belongs to the cache kmalloc-4096 of size 4096 The buggy address is located 264 bytes inside of 4096-byte region [ffff888018a0e3c0, ffff888018a0f3c0) The buggy address belongs to the page: page:ffffea0000628380 count:1 mapcount:0 mapping:ffff88812c3f6dc0 index:0x0 compound_mapcount: 0 flags: 0xfffe0000008100(slab|head) raw: 00fffe0000008100 ffffea0001358688 ffffea0001296b08 ffff88812c3f6dc0 raw: 0000000000000000 ffff888018a0e3c0 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888018a0e380: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff888018a0e400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888018a0e480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888018a0e500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888018a0e580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================