================================================================== BUG: KASAN: use-after-free in tcf_block_find+0x9d1/0xb90 net/sched/cls_api.c:646 Read of size 4 at addr ffff8801d35bd278 by task syz-executor610/6307 CPU: 1 PID: 6307 Comm: syz-executor610 Not tainted 4.19.0-rc5-next-20180928+ #84 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+0x1d3/0x2c4 lib/dump_stack.c:113 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432 tcf_block_find+0x9d1/0xb90 net/sched/cls_api.c:646 tc_new_tfilter+0x497/0x1d10 net/sched/cls_api.c:1331 rtnetlink_rcv_msg+0x46a/0xc20 net/core/rtnetlink.c:4730 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2447 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4748 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x5a5/0x760 net/netlink/af_netlink.c:1336 netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:632 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2117 __sys_sendmsg+0x11d/0x280 net/socket.c:2155 __do_sys_sendmsg net/socket.c:2164 [inline] __se_sys_sendmsg net/socket.c:2162 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2162 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x441a19 Code: e8 0c ac 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 fb 04 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffd45a788b8 EFLAGS: 00000213 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441a19 RDX: 0000000000000000 RSI: 0000000020005000 RDI: 0000000000000003 RBP: 000000000000d893 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000252d880 R11: 0000000000000213 R12: 0000000000000000 R13: 0000000000402430 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 6122: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 __do_kmalloc_node mm/slab.c:3682 [inline] __kmalloc_node+0x47/0x70 mm/slab.c:3689 kmalloc_node include/linux/slab.h:589 [inline] kzalloc_node include/linux/slab.h:752 [inline] qdisc_alloc+0x10f/0xb50 net/sched/sch_generic.c:820 qdisc_create_dflt+0x7a/0x1e0 net/sched/sch_generic.c:894 attach_one_default_qdisc net/sched/sch_generic.c:1041 [inline] netdev_for_each_tx_queue include/linux/netdevice.h:2117 [inline] attach_default_qdiscs net/sched/sch_generic.c:1060 [inline] dev_activate+0x82f/0xcb0 net/sched/sch_generic.c:1103 __dev_open+0x2cb/0x410 net/core/dev.c:1400 __dev_change_flags+0x730/0x9b0 net/core/dev.c:7448 dev_change_flags+0x89/0x150 net/core/dev.c:7517 do_setlink+0xb5f/0x3f20 net/core/rtnetlink.c:2441 rtnl_newlink+0x136f/0x1d40 net/core/rtnetlink.c:3054 rtnetlink_rcv_msg+0x46a/0xc20 net/core/rtnetlink.c:4730 netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2447 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4748 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x5a5/0x760 net/netlink/af_netlink.c:1336 netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:632 ___sys_sendmsg+0x7fd/0x930 net/socket.c:2117 __sys_sendmsg+0x11d/0x280 net/socket.c:2155 __do_sys_sendmsg net/socket.c:2164 [inline] __se_sys_sendmsg net/socket.c:2162 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2162 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 9: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xcf/0x230 mm/slab.c:3813 qdisc_free+0x89/0x100 net/sched/sch_generic.c:941 qdisc_free_cb+0x19/0x20 net/sched/sch_generic.c:948 __rcu_reclaim kernel/rcu/rcu.h:240 [inline] rcu_do_batch kernel/rcu/tree.c:2437 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2716 [inline] rcu_process_callbacks+0xff9/0x1ad0 kernel/rcu/tree.c:2697 __do_softirq+0x30b/0xb03 kernel/softirq.c:292 The buggy address belongs to the object at ffff8801d35bd240 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 56 bytes inside of 1024-byte region [ffff8801d35bd240, ffff8801d35bd640) The buggy address belongs to the page: page:ffffea00074d6f00 count:1 mapcount:0 mapping:ffff8801da800ac0 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000010200(slab|head) raw: 02fffc0000010200 ffffea0007561e88 ffffea00074cc408 ffff8801da800ac0 raw: 0000000000000000 ffff8801d35bc040 0000000100000007 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d35bd100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d35bd180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8801d35bd200: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff8801d35bd280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d35bd300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================