================================================================== BUG: KASAN: use-after-free in __in_dev_get_rtnl include/linux/inetdevice.h:236 [inline] BUG: KASAN: use-after-free in inet_gifconf+0xb5/0x420 net/ipv4/devinet.c:1243 Read of size 8 at addr ffff88805d19e318 by task syz-executor.4/12770 CPU: 0 PID: 12770 Comm: syz-executor.4 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+0x1fb/0x318 lib/dump_stack.c:118 print_address_description+0x74/0x5c0 mm/kasan/report.c:374 __kasan_report+0x149/0x1c0 mm/kasan/report.c:506 kasan_report+0x26/0x50 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+0xb5/0x420 net/ipv4/devinet.c:1243 dev_ifconf+0x123/0x220 net/core/dev_ioctl.c:78 sock_do_ioctl+0x130/0x260 net/socket.c:1067 sock_ioctl+0x464/0x690 net/socket.c:1204 vfs_ioctl fs/ioctl.c:47 [inline] ksys_ioctl fs/ioctl.c:763 [inline] __do_sys_ioctl fs/ioctl.c:772 [inline] __se_sys_ioctl+0x113/0x190 fs/ioctl.c:770 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:770 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45c449 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:00007f535b803c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f535b8046d4 RCX: 000000000045c449 RDX: 0000000000400200 RSI: 0000000000008912 RDI: 0000000000000006 RBP: 000000000076bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000000040e R14: 00000000004c66d9 R15: 000000000076bf2c Allocated by task 8790: save_stack mm/kasan/common.c:72 [inline] set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc+0x118/0x1c0 mm/kasan/common.c:515 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:529 __do_kmalloc_node mm/slab.c:3616 [inline] __kmalloc_node+0x4d/0x60 mm/slab.c:3623 kmalloc_node include/linux/slab.h:578 [inline] kvmalloc_node+0x85/0x110 mm/util.c:574 kvmalloc include/linux/mm.h:645 [inline] kvzalloc include/linux/mm.h:653 [inline] alloc_netdev_mqs+0x8e/0xd40 net/core/dev.c:9797 vti6_init_net+0x112/0x320 net/ipv6/ip6_vti.c:1119 ops_init+0x355/0x430 net/core/net_namespace.c:137 setup_net+0x1eb/0x7f0 net/core/net_namespace.c:327 copy_net_ns+0x334/0x540 net/core/net_namespace.c:468 create_new_namespaces+0x4d7/0x9c0 kernel/nsproxy.c:108 unshare_nsproxy_namespaces+0x12a/0x190 kernel/nsproxy.c:229 ksys_unshare+0x478/0xa00 kernel/fork.c:2955 __do_sys_unshare kernel/fork.c:3023 [inline] __se_sys_unshare kernel/fork.c:3021 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3021 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 12693: save_stack mm/kasan/common.c:72 [inline] set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:337 [inline] __kasan_slab_free+0x12e/0x1e0 mm/kasan/common.c:476 kasan_slab_free+0xe/0x10 mm/kasan/common.c:485 __cache_free mm/slab.c:3426 [inline] kfree+0x10d/0x220 mm/slab.c:3757 __netdev_name_node_alt_destroy net/core/dev.c:322 [inline] netdev_name_node_alt_destroy+0x35c/0x380 net/core/dev.c:334 rtnl_alt_ifname net/core/rtnetlink.c:3518 [inline] rtnl_linkprop+0x42d/0x680 net/core/rtnetlink.c:3567 rtnl_dellinkprop+0x2a/0x40 net/core/rtnetlink.c:3588 rtnetlink_rcv_msg+0x889/0xd40 net/core/rtnetlink.c:5438 netlink_rcv_skb+0x19e/0x3e0 net/netlink/af_netlink.c:2477 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5456 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] netlink_unicast+0x766/0x920 net/netlink/af_netlink.c:1328 netlink_sendmsg+0xa2b/0xd40 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x4f7/0x7f0 net/socket.c:2343 ___sys_sendmsg net/socket.c:2397 [inline] __sys_sendmsg+0x1ed/0x290 net/socket.c:2430 __do_sys_sendmsg net/socket.c:2439 [inline] __se_sys_sendmsg net/socket.c:2437 [inline] __x64_sys_sendmsg+0x7f/0x90 net/socket.c:2437 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff88805d19e000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 792 bytes inside of 4096-byte region [ffff88805d19e000, ffff88805d19f000) The buggy address belongs to the page: page:ffffea0001746780 refcount:1 mapcount:0 mapping:ffff8880aa402000 index:0x0 compound_mapcount: 0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea0001746708 ffffea0001746d88 ffff8880aa402000 raw: 0000000000000000 ffff88805d19e000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88805d19e200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805d19e280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805d19e300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805d19e380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805d19e400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================