netlink: 12 bytes leftover after parsing attributes in process `syz-executor5'. ================================================================== BUG: KASAN: use-after-free in nla_strlcpy+0x13d/0x150 lib/nlattr.c:314 Read of size 1 at addr ffff8801cb8ad8dd by task syz-executor7/26340 CPU: 0 PID: 26340 Comm: syz-executor7 Not tainted 4.17.0-rc6+ #69 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+0x1b9/0x294 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430 nla_strlcpy+0x13d/0x150 lib/nlattr.c:314 nfnl_acct_new+0x574/0xc50 net/netfilter/nfnetlink_acct.c:118 nfnetlink_rcv_msg+0xdb5/0xff0 net/netfilter/nfnetlink.c:212 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2448 nfnetlink_rcv+0x1fe/0x1ba0 net/netfilter/nfnetlink.c:513 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x58b/0x740 net/netlink/af_netlink.c:1336 netlink_sendmsg+0x9f0/0xfa0 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:639 sock_write_iter+0x35a/0x5a0 net/socket.c:908 call_write_iter include/linux/fs.h:1784 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x64d/0x960 fs/read_write.c:487 vfs_write+0x1f8/0x560 fs/read_write.c:549 ksys_write+0xf9/0x250 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455a09 RSP: 002b:00007ff6113a3c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ff6113a46d4 RCX: 0000000000455a09 RDX: 000000000000005d RSI: 0000000020000040 RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000007a8 R14: 0000000000700860 R15: 0000000000000000 Allocated by task 25868: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554 __split_vma+0x11a/0x7f0 mm/mmap.c:2623 do_munmap+0xcfa/0xf90 mm/mmap.c:2746 vm_munmap+0x120/0x1a0 mm/mmap.c:2804 __do_sys_munmap mm/mmap.c:2814 [inline] __se_sys_munmap mm/mmap.c:2811 [inline] __x64_sys_munmap+0x60/0x80 mm/mmap.c:2811 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 25868: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x86/0x2d0 mm/slab.c:3756 remove_vma+0x164/0x1b0 mm/mmap.c:185 remove_vma_list mm/mmap.c:2549 [inline] do_munmap+0x743/0xf90 mm/mmap.c:2790 vm_munmap+0x120/0x1a0 mm/mmap.c:2804 __do_sys_munmap mm/mmap.c:2814 [inline] __se_sys_munmap mm/mmap.c:2811 [inline] __x64_sys_munmap+0x60/0x80 mm/mmap.c:2811 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801cb8ad880 which belongs to the cache vm_area_struct of size 200 The buggy address is located 93 bytes inside of 200-byte region [ffff8801cb8ad880, ffff8801cb8ad948) The buggy address belongs to the page: page:ffffea00072e2b40 count:1 mapcount:0 mapping:ffff8801cb8ad040 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801cb8ad040 0000000000000000 000000010000000f raw: ffffea0006d5ad20 ffffea0007425a20 ffff8801da97a840 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801cb8ad780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801cb8ad800: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8801cb8ad880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801cb8ad900: fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc ffff8801cb8ad980: fc fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================