================================================================== BUG: KASAN: use-after-free in erspan_build_header+0x3bf/0x3d0 net/ipv4/ip_gre.c:698 Read of size 2 at addr ffff8801cf17584b by task syz-executor0/6802 CPU: 1 PID: 6802 Comm: syz-executor0 Not tainted 4.15.0-rc9+ #275 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 SELinux: unknown mount option 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: 0033:0x452ef9 RSP: 002b:00007f1cfff1fc58 EFLAGS: 00000212 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452ef9 RDX: 0000000000000000 RSI: 0000000020015f41 RDI: 0000000000000014 RBP: 0000000000000431 R08: 0000000020015fec R09: 0000000000000014 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f5538 R13: 00000000ffffffff R14: 00007f1cfff206d4 R15: 0000000000000000 Allocated by task 4899: 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+0x12e/0x760 mm/slab.c:3544 kmem_cache_zalloc include/linux/slab.h:678 [inline] taskstats_tgid_alloc kernel/taskstats.c:577 [inline] taskstats_exit+0x7b5/0xfc0 kernel/taskstats.c:610 do_exit+0x44a/0x1ad0 kernel/exit.c:850 do_group_exit+0x149/0x400 kernel/exit.c:968 SYSC_exit_group kernel/exit.c:979 [inline] SyS_exit_group+0x1d/0x20 kernel/exit.c:977 entry_SYSCALL_64_fastpath+0x29/0xa0 Freed by task 4927: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3488 [inline] kmem_cache_free+0x83/0x2a0 mm/slab.c:3746 taskstats_tgid_free include/linux/taskstats_kern.h:22 [inline] free_signal_struct kernel/fork.c:395 [inline] put_signal_struct kernel/fork.c:409 [inline] __put_task_struct+0x2ec/0x580 kernel/fork.c:423 put_task_struct include/linux/sched/task.h:96 [inline] delayed_put_task_struct+0xca/0x3d0 kernel/exit.c:180 __rcu_reclaim kernel/rcu/rcu.h:195 [inline] rcu_do_batch kernel/rcu/tree.c:2758 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:3012 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2979 [inline] rcu_process_callbacks+0xd6c/0x17f0 kernel/rcu/tree.c:2996 __do_softirq+0x2d7/0xb85 kernel/softirq.c:285 The buggy address belongs to the object at ffff8801cf1757a8 which belongs to the cache taskstats of size 328 The buggy address is located 163 bytes inside of 328-byte region [ffff8801cf1757a8, ffff8801cf1758f0) The buggy address belongs to the page: page:ffffea00073c5d40 count:1 mapcount:0 mapping:ffff8801cf175000 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801cf175000 0000000000000000 000000010000000a raw: ffffea00073e4a20 ffffea0007234ba0 ffff8801d9ea27c0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801cf175700: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ffff8801cf175780: fc fc fc fc fc fb fb fb fb fb fb fb fb fb fb fb >ffff8801cf175800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801cf175880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc ffff8801cf175900: fc fc fc fc fc fc fb fb fb fb fb fb fb fb fb fb ==================================================================