netlink: 10 bytes leftover after parsing attributes in process `syz-executor6'. ================================================================== BUG: KASAN: use-after-free in erspan_build_header+0x3bf/0x3d0 net/ipv4/ip_gre.c:698 Read of size 2 at addr ffff8801ca70a04b by task syz-executor5/17234 CPU: 1 PID: 17234 Comm: syz-executor5 Not tainted 4.15.0+ #286 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x25b/0x340 mm/kasan/report.c:409 __asan_report_load_n_noabort+0xf/0x20 mm/kasan/report.c:440 erspan_build_header+0x3bf/0x3d0 net/ipv4/ip_gre.c:698 erspan_xmit+0x3b8/0x13b0 net/ipv4/ip_gre.c:740 __netdev_start_xmit include/linux/netdevice.h:4042 [inline] netdev_start_xmit include/linux/netdevice.h:4051 [inline] packet_direct_xmit+0x315/0x6b0 net/packet/af_packet.c:266 packet_snd net/packet/af_packet.c:2943 [inline] packet_sendmsg+0x3aed/0x60b0 net/packet/af_packet.c:2968 sock_sendmsg_nosec net/socket.c:638 [inline] sock_sendmsg+0xca/0x110 net/socket.c:648 SYSC_sendto+0x361/0x5c0 net/socket.c:1729 SyS_sendto+0x40/0x50 net/socket.c:1697 entry_SYSCALL_64_fastpath+0x29/0xa0 RIP: 0033:0x453299 RSP: 002b:00007f717337fc58 EFLAGS: 00000212 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000453299 RDX: 00000000000001dc RSI: 000000002000c000 RDI: 0000000000000013 RBP: 000000000000059d R08: 0000000020008000 R09: 000000000000001c R10: 0000000000000010 R11: 0000000000000212 R12: 00000000006f7758 R13: 00000000ffffffff R14: 00007f71733806d4 R15: 0000000000000000 Allocated by task 17226: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489 kmem_cache_alloc_node+0x144/0x760 mm/slab.c:3634 alloc_task_struct_node kernel/fork.c:156 [inline] dup_task_struct kernel/fork.c:521 [inline] copy_process.part.38+0x198d/0x4b20 kernel/fork.c:1590 copy_process kernel/fork.c:1565 [inline] _do_fork+0x1f7/0xfe0 kernel/fork.c:2044 SYSC_clone kernel/fork.c:2154 [inline] SyS_clone+0x37/0x50 kernel/fork.c:2148 do_syscall_64+0x273/0x920 arch/x86/entry/common.c:285 return_from_SYSCALL_64+0x0/0x75 Freed by task 0: (stack is not available) The buggy address belongs to the object at ffff8801ca70a640 which belongs to the cache task_struct of size 6016 The buggy address is located 1525 bytes to the left of 6016-byte region [ffff8801ca70a640, ffff8801ca70bdc0) The buggy address belongs to the page: page:ffffea000729c280 count:1 mapcount:0 mapping:ffff8801ca70a640 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000008100(slab|head) raw: 02fffc0000008100 ffff8801ca70a640 0000000000000000 0000000100000001 raw: ffffea000722dd20 ffffea000729dc20 ffff8801db131200 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801ca709f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801ca709f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801ca70a000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8801ca70a080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801ca70a100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================