================================================================== BUG: KASAN: use-after-free in rtnl_newlink+0x1527/0x15b0 net/core/rtnetlink.c:3149 Read of size 1 at addr ffff8880717cc628 by task syz-executor.2/20947 CPU: 1 PID: 20947 Comm: syz-executor.2 Not tainted 4.19.176-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+0x1fc/0x2ef lib/dump_stack.c:118 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256 kasan_report_error.cold+0x8a/0x1b9 mm/kasan/report.c:354 kasan_report mm/kasan/report.c:412 [inline] __asan_report_load1_noabort+0x88/0x90 mm/kasan/report.c:430 rtnl_newlink+0x1527/0x15b0 net/core/rtnetlink.c:3149 rtnetlink_rcv_msg+0x453/0xb80 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+0x6bb/0xc40 net/netlink/af_netlink.c:1909 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:632 ___sys_sendmsg+0x7bb/0x8e0 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+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x466019 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fef78539188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466019 RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000003 RBP: 00000000004bd067 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007fffdecd9edf R14: 00007fef78539300 R15: 0000000000022000 Allocated by task 20947: __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+0xb4/0xf0 mm/util.c:423 kvmalloc include/linux/mm.h:577 [inline] kvzalloc include/linux/mm.h:585 [inline] alloc_netdev_mqs+0x97/0xd50 net/core/dev.c:9144 rtnl_create_link+0x1d4/0xa40 net/core/rtnetlink.c:2869 rtnl_newlink+0xf3c/0x15b0 net/core/rtnetlink.c:3131 rtnetlink_rcv_msg+0x453/0xb80 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+0x6bb/0xc40 net/netlink/af_netlink.c:1909 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:632 ___sys_sendmsg+0x7bb/0x8e0 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+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 20947: __cache_free mm/slab.c:3503 [inline] kfree+0xcc/0x210 mm/slab.c:3822 kvfree+0x59/0x60 mm/util.c:452 netdev_freemem net/core/dev.c:9098 [inline] free_netdev+0x364/0x410 net/core/dev.c:9249 device_release+0x76/0x210 drivers/base/core.c:1076 kobject_cleanup lib/kobject.c:662 [inline] kobject_release lib/kobject.c:691 [inline] kref_put include/linux/kref.h:70 [inline] kobject_put+0x28b/0x5d0 lib/kobject.c:708 put_device drivers/base/core.c:2266 [inline] device_unregister+0x35/0xc0 drivers/base/core.c:2378 register_netdevice+0x901/0x10f0 net/core/dev.c:8783 nsim_newlink+0x162/0x1c0 drivers/net/netdevsim/netdev.c:555 rtnl_newlink+0x1027/0x15b0 net/core/rtnetlink.c:3141 rtnetlink_rcv_msg+0x453/0xb80 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+0x6bb/0xc40 net/netlink/af_netlink.c:1909 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xc3/0x120 net/socket.c:632 ___sys_sendmsg+0x7bb/0x8e0 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+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880717cc0c0 which belongs to the cache kmalloc-8192 of size 8192 The buggy address is located 1384 bytes inside of 8192-byte region [ffff8880717cc0c0, ffff8880717ce0c0) The buggy address belongs to the page: page:ffffea0001c5f300 count:1 mapcount:0 mapping:ffff88813bff2080 index:0x0 compound_mapcount: 0 flags: 0xfff00000008100(slab|head) raw: 00fff00000008100 ffffea0002a2d308 ffff88813bff1b48 ffff88813bff2080 raw: 0000000000000000 ffff8880717cc0c0 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880717cc500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880717cc580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880717cc600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880717cc680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880717cc700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================