================================================================== BUG: KASAN: use-after-free in macvlan_dev_get_iflink+0x6a/0x70 drivers/net/macvlan.c:1128 Read of size 4 at addr ffff88809dacc100 by task syz-executor.3/2176 CPU: 0 PID: 2176 Comm: syz-executor.3 Not tainted 5.7.0-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+0x1e9/0x30e lib/dump_stack.c:118 print_address_description+0x66/0x5a0 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report+0x132/0x1d0 mm/kasan/report.c:530 macvlan_dev_get_iflink+0x6a/0x70 drivers/net/macvlan.c:1128 default_operstate net/core/link_watch.c:41 [inline] rfc2863_policy+0x11f/0x2a0 net/core/link_watch.c:53 linkwatch_do_dev+0x3a/0x160 net/core/link_watch.c:160 netdev_wait_allrefs net/core/dev.c:9667 [inline] netdev_run_todo+0x2c8/0xcb0 net/core/dev.c:9763 rtnl_unlock net/core/rtnetlink.c:112 [inline] rtnetlink_rcv_msg+0x890/0xd40 net/core/rtnetlink.c:5462 netlink_rcv_skb+0x190/0x3a0 net/netlink/af_netlink.c:2469 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x786/0x940 net/netlink/af_netlink.c:1329 netlink_sendmsg+0xa57/0xd70 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x519/0x800 net/socket.c:2352 ___sys_sendmsg net/socket.c:2406 [inline] __sys_sendmsg+0x2b1/0x360 net/socket.c:2439 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x45ca59 Code: 0d b7 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 b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fdac3eacc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000501a20 RCX: 000000000045ca59 RDX: 0000000000000000 RSI: 0000000020000080 RDI: 0000000000000006 RBP: 000000000078bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000a21 R14: 00000000004cd03c R15: 00007fdac3ead6d4 Allocated by task 2162: save_stack mm/kasan/common.c:48 [inline] set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc+0x103/0x140 mm/kasan/common.c:494 kmalloc_node include/linux/slab.h:578 [inline] kvmalloc_node+0x81/0x110 mm/util.c:574 kvmalloc include/linux/mm.h:752 [inline] kvzalloc include/linux/mm.h:760 [inline] alloc_netdev_mqs+0x86/0xfa0 net/core/dev.c:9927 rtnl_create_link+0x242/0x9c0 net/core/rtnetlink.c:3068 __rtnl_newlink net/core/rtnetlink.c:3330 [inline] rtnl_newlink+0x12a2/0x1c00 net/core/rtnetlink.c:3398 rtnetlink_rcv_msg+0x889/0xd40 net/core/rtnetlink.c:5461 netlink_rcv_skb+0x190/0x3a0 net/netlink/af_netlink.c:2469 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x786/0x940 net/netlink/af_netlink.c:1329 netlink_sendmsg+0xa57/0xd70 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x519/0x800 net/socket.c:2352 ___sys_sendmsg net/socket.c:2406 [inline] __sys_sendmsg+0x2b1/0x360 net/socket.c:2439 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Freed by task 2162: save_stack mm/kasan/common.c:48 [inline] set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0x114/0x170 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x220 mm/slab.c:3757 device_release+0x70/0x1a0 drivers/base/core.c:1390 kobject_cleanup lib/kobject.c:693 [inline] kobject_release lib/kobject.c:722 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1cf/0x290 lib/kobject.c:739 netdev_run_todo+0xb37/0xcb0 net/core/dev.c:9786 rtnl_unlock net/core/rtnetlink.c:112 [inline] rtnetlink_rcv_msg+0x890/0xd40 net/core/rtnetlink.c:5462 netlink_rcv_skb+0x190/0x3a0 net/netlink/af_netlink.c:2469 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0x786/0x940 net/netlink/af_netlink.c:1329 netlink_sendmsg+0xa57/0xd70 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x519/0x800 net/socket.c:2352 ___sys_sendmsg net/socket.c:2406 [inline] __sys_sendmsg+0x2b1/0x360 net/socket.c:2439 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 The buggy address belongs to the object at ffff88809dacc000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 256 bytes inside of 4096-byte region [ffff88809dacc000, ffff88809dacd000) The buggy address belongs to the page: page:ffffea000276b300 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 head:ffffea000276b300 order:1 compound_mapcount:0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea000212c488 ffffea000257e088 ffff8880aa402000 raw: 0000000000000000 ffff88809dacc000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809dacc000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809dacc080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88809dacc100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88809dacc180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809dacc200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================