================================================================== BUG: KASAN: use-after-free in dev_net include/linux/netdevice.h:2220 [inline] BUG: KASAN: use-after-free in inet_lookup_ifaddr_rcu+0x189/0x1b0 net/ipv4/devinet.c:188 Read of size 8 at addr ffff88804fd56588 by task syz-executor.3/23996 CPU: 0 PID: 23996 Comm: syz-executor.3 Not tainted 5.6.0-rc2-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+0x197/0x210 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 __kasan_report.cold+0x1b/0x32 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:641 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 dev_net include/linux/netdevice.h:2220 [inline] inet_lookup_ifaddr_rcu+0x189/0x1b0 net/ipv4/devinet.c:188 __ip_dev_find+0x113/0x410 net/ipv4/devinet.c:156 ip_route_output_key_hash_rcu+0x1962/0x2d60 net/ipv4/route.c:2564 ip_route_output_key_hash+0x1ef/0x360 net/ipv4/route.c:2500 __ip_route_output_key include/net/route.h:126 [inline] ip_route_output_flow+0x28/0xc0 net/ipv4/route.c:2763 ip_route_output_key include/net/route.h:136 [inline] sctp_v4_get_dst+0xe3a/0x1470 net/sctp/protocol.c:495 sctp_transport_route+0x12d/0x360 net/sctp/transport.c:297 sctp_assoc_add_peer+0x5a8/0x1040 net/sctp/associola.c:659 sctp_connect_new_asoc+0x1a7/0x5a0 net/sctp/socket.c:1077 sctp_sendmsg_new_asoc net/sctp/socket.c:1679 [inline] sctp_sendmsg+0x13a0/0x1f10 net/sctp/socket.c:1989 inet_sendmsg+0x9e/0xe0 net/ipv4/af_inet.c:807 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:672 __sys_sendto+0x262/0x380 net/socket.c:1998 __do_sys_sendto net/socket.c:2010 [inline] __se_sys_sendto net/socket.c:2006 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:2006 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c429 Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007effadb85c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007effadb866d4 RCX: 000000000045c429 RDX: 0000000000000001 RSI: 0000000020000180 RDI: 0000000000000003 RBP: 000000000076bf20 R08: 00000000200001c0 R09: 0000000000000010 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000a03 R14: 00000000004cc764 R15: 000000000076bf2c Allocated by task 9719: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:515 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:488 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:529 __do_kmalloc_node mm/slab.c:3616 [inline] __kmalloc_node+0x4e/0x70 mm/slab.c:3623 kmalloc_node include/linux/slab.h:578 [inline] kvmalloc_node+0x68/0x100 mm/util.c:574 kvmalloc include/linux/mm.h:645 [inline] kvzalloc include/linux/mm.h:653 [inline] alloc_netdev_mqs+0x98/0xe40 net/core/dev.c:9797 rtnl_create_link+0x22d/0xaf0 net/core/rtnetlink.c:3047 __rtnl_newlink+0xf9f/0x1790 net/core/rtnetlink.c:3309 rtnl_newlink+0x69/0xa0 net/core/rtnetlink.c:3377 rtnetlink_rcv_msg+0x45e/0xaf0 net/core/rtnetlink.c:5438 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5456 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x59e/0x7e0 net/netlink/af_netlink.c:1328 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:672 __sys_sendto+0x262/0x380 net/socket.c:1998 __do_sys_sendto net/socket.c:2010 [inline] __se_sys_sendto net/socket.c:2006 [inline] __x64_sys_sendto+0xe1/0x1a0 net/socket.c:2006 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 23881: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:337 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:476 kasan_slab_free+0xe/0x10 mm/kasan/common.c:485 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x2c0 mm/slab.c:3757 __netdev_name_node_alt_destroy+0x1ff/0x2a0 net/core/dev.c:322 netdev_name_node_alt_destroy+0x57/0x80 net/core/dev.c:334 rtnl_alt_ifname net/core/rtnetlink.c:3518 [inline] rtnl_linkprop.isra.0+0x575/0x6f0 net/core/rtnetlink.c:3567 rtnl_dellinkprop+0x46/0x60 net/core/rtnetlink.c:3588 rtnetlink_rcv_msg+0x45e/0xaf0 net/core/rtnetlink.c:5438 netlink_rcv_skb+0x177/0x450 net/netlink/af_netlink.c:2477 rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5456 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x59e/0x7e0 net/netlink/af_netlink.c:1328 netlink_sendmsg+0x91c/0xea0 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:672 ____sys_sendmsg+0x753/0x880 net/socket.c:2343 ___sys_sendmsg+0x100/0x170 net/socket.c:2397 __sys_sendmsg+0x105/0x1d0 net/socket.c:2430 __do_sys_sendmsg net/socket.c:2439 [inline] __se_sys_sendmsg net/socket.c:2437 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2437 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88804fd56000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1416 bytes inside of 4096-byte region [ffff88804fd56000, ffff88804fd57000) The buggy address belongs to the page: page:ffffea00013f5580 refcount:1 mapcount:0 mapping:ffff8880aa402000 index:0x0 compound_mapcount: 0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea00013f5508 ffffea00013f5608 ffff8880aa402000 raw: 0000000000000000 ffff88804fd56000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88804fd56480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804fd56500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88804fd56580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88804fd56600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88804fd56680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================