netlink: 4 bytes leftover after parsing attributes in process `syz-executor.0'. ================================================================== BUG: KASAN: slab-out-of-bounds in ipt_init_target+0x213/0x250 net/sched/act_ipt.c:46 Read of size 1 at addr ffff8880a967415f by task syz-executor.0/4507 CPU: 1 PID: 4507 Comm: syz-executor.0 Not tainted 4.14.231-syzkaller #0 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+0x1b2/0x281 lib/dump_stack.c:58 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252 kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351 kasan_report mm/kasan/report.c:409 [inline] __asan_report_load1_noabort+0x68/0x70 mm/kasan/report.c:427 ipt_init_target+0x213/0x250 net/sched/act_ipt.c:46 __tcf_ipt_init+0x48d/0xc00 net/sched/act_ipt.c:168 tcf_xt_init+0x43/0x50 net/sched/act_ipt.c:210 tcf_action_init_1+0x51a/0x9e0 net/sched/act_api.c:682 tcf_action_init+0x26d/0x400 net/sched/act_api.c:751 tcf_action_add net/sched/act_api.c:1079 [inline] tc_ctl_action+0x2e3/0x510 net/sched/act_api.c:1131 rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4316 netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2433 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline] netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1313 netlink_sendmsg+0x62e/0xb80 net/netlink/af_netlink.c:1878 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xb5/0x100 net/socket.c:656 sock_no_sendpage+0xe2/0x110 net/core/sock.c:2595 kernel_sendpage net/socket.c:3407 [inline] sock_sendpage+0xdf/0x140 net/socket.c:871 pipe_to_sendpage+0x226/0x2d0 fs/splice.c:451 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x326/0x7a0 fs/splice.c:626 splice_from_pipe fs/splice.c:661 [inline] generic_splice_sendpage+0xc1/0x110 fs/splice.c:832 do_splice_from fs/splice.c:851 [inline] do_splice fs/splice.c:1147 [inline] SYSC_splice fs/splice.c:1402 [inline] SyS_splice+0xd59/0x1380 fs/splice.c:1382 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb RIP: 0033:0x466459 RSP: 002b:00007fa37ef44188 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000466459 RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00000000004bf9fb R08: 000000000004ffe0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008 R13: 00007ffd2e6360ff R14: 00007fa37ef44300 R15: 0000000000022000 Allocated by task 4507: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551 __do_kmalloc mm/slab.c:3720 [inline] __kmalloc_track_caller+0x155/0x400 mm/slab.c:3735 kmemdup+0x23/0x50 mm/util.c:118 kmemdup include/linux/string.h:449 [inline] __tcf_ipt_init+0x464/0xc00 net/sched/act_ipt.c:164 tcf_xt_init+0x43/0x50 net/sched/act_ipt.c:210 tcf_action_init_1+0x51a/0x9e0 net/sched/act_api.c:682 tcf_action_init+0x26d/0x400 net/sched/act_api.c:751 tcf_action_add net/sched/act_api.c:1079 [inline] tc_ctl_action+0x2e3/0x510 net/sched/act_api.c:1131 rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4316 netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2433 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline] netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1313 netlink_sendmsg+0x62e/0xb80 net/netlink/af_netlink.c:1878 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xb5/0x100 net/socket.c:656 sock_no_sendpage+0xe2/0x110 net/core/sock.c:2595 kernel_sendpage net/socket.c:3407 [inline] sock_sendpage+0xdf/0x140 net/socket.c:871 pipe_to_sendpage+0x226/0x2d0 fs/splice.c:451 splice_from_pipe_feed fs/splice.c:502 [inline] __splice_from_pipe+0x326/0x7a0 fs/splice.c:626 splice_from_pipe fs/splice.c:661 [inline] generic_splice_sendpage+0xc1/0x110 fs/splice.c:832 do_splice_from fs/splice.c:851 [inline] do_splice fs/splice.c:1147 [inline] SYSC_splice fs/splice.c:1402 [inline] SyS_splice+0xd59/0x1380 fs/splice.c:1382 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 3416: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xc9/0x250 mm/slab.c:3815 do_delayed_call include/linux/delayed_call.h:28 [inline] put_link fs/namei.c:900 [inline] step_into fs/namei.c:1787 [inline] walk_component+0x1bf/0xbc0 fs/namei.c:1844 link_path_walk+0x4cb/0x10a0 fs/namei.c:2151 path_openat+0x15e/0x2970 fs/namei.c:3568 do_filp_open+0x179/0x3c0 fs/namei.c:3603 do_sys_open+0x296/0x410 fs/open.c:1081 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb The buggy address belongs to the object at ffff8880a9674140 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 31 bytes inside of 32-byte region [ffff8880a9674140, ffff8880a9674160) The buggy address belongs to the page: page:ffffea0002a59d00 count:1 mapcount:0 mapping:ffff8880a9674000 index:0xffff8880a9674fc1 flags: 0xfff00000000100(slab) raw: 00fff00000000100 ffff8880a9674000 ffff8880a9674fc1 000000010000003e raw: ffffea0002ab6960 ffffea0002876fe0 ffff88813fe801c0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a9674000: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ffff8880a9674080: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc >ffff8880a9674100: fb fb fb fb fc fc fc fc 07 fc fc fc fc fc fc fc ^ ffff8880a9674180: 07 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc ffff8880a9674200: 07 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc ==================================================================