================================================================== BUG: KASAN: use-after-free in __in_dev_get_rtnl include/linux/inetdevice.h:236 [inline] BUG: KASAN: use-after-free in inet_gifconf+0x47e/0x490 net/ipv4/devinet.c:1243 Read of size 8 at addr ffff888062a16318 by task syz-executor.2/19564 CPU: 0 PID: 19564 Comm: syz-executor.2 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 __in_dev_get_rtnl include/linux/inetdevice.h:236 [inline] inet_gifconf+0x47e/0x490 net/ipv4/devinet.c:1243 dev_ifconf+0xd0/0x230 net/core/dev_ioctl.c:80 sock_do_ioctl+0x260/0x2f0 net/socket.c:1067 sock_ioctl+0x3ed/0x790 net/socket.c:1204 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl+0x123/0x180 fs/ioctl.c:763 __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl fs/ioctl.c:770 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:770 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c6c9 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:00007fabe5dc8c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fabe5dc96d4 RCX: 000000000045c6c9 RDX: 0000000000400200 RSI: 0000000000008912 RDI: 0000000000000004 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000040e R14: 00000000004c698c R15: 000000000076bf2c Allocated by task 10165: 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 vti6_init_net+0x244/0x810 net/ipv6/ip6_vti.c:1119 ops_init+0xb3/0x420 net/core/net_namespace.c:137 setup_net+0x2d5/0x8b0 net/core/net_namespace.c:327 copy_net_ns+0x29e/0x5a0 net/core/net_namespace.c:468 create_new_namespaces+0x403/0xb50 kernel/nsproxy.c:108 unshare_nsproxy_namespaces+0xc2/0x200 kernel/nsproxy.c:229 ksys_unshare+0x444/0x980 kernel/fork.c:2955 __do_sys_unshare kernel/fork.c:3023 [inline] __se_sys_unshare kernel/fork.c:3021 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3021 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 19497: 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 ffff888062a16000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 792 bytes inside of 4096-byte region [ffff888062a16000, ffff888062a17000) The buggy address belongs to the page: page:ffffea00018a8580 refcount:1 mapcount:0 mapping:ffff8880aa402000 index:0x0 compound_mapcount: 0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea00018a8508 ffffea00018a8788 ffff8880aa402000 raw: 0000000000000000 ffff888062a16000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888062a16200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888062a16280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888062a16300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888062a16380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888062a16400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================