netlink: 24 bytes leftover after parsing attributes in process `syz-executor.5'. hrtimer: interrupt took 58967 ns ================================================================== BUG: KASAN: use-after-free in u32_destroy_key.constprop.0.isra.0+0x1a4/0x1d0 net/sched/cls_u32.c:405 Read of size 4 at addr ffff8880af751618 by task kworker/u4:4/2883 CPU: 1 PID: 2883 Comm: kworker/u4:4 Not tainted 4.14.250-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: tc_filter_workqueue u32_delete_key_freepf_work 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_load4_noabort+0x68/0x70 mm/kasan/report.c:429 u32_destroy_key.constprop.0.isra.0+0x1a4/0x1d0 net/sched/cls_u32.c:405 u32_delete_key_freepf_work+0x1c/0x30 net/sched/cls_u32.c:456 process_one_work+0x793/0x14a0 kernel/workqueue.c:2117 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251 kthread+0x30d/0x420 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Allocated by task 10103: 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 kmem_cache_alloc_trace+0x131/0x3d0 mm/slab.c:3618 kmalloc include/linux/slab.h:488 [inline] kzalloc include/linux/slab.h:661 [inline] u32_init+0x3e4/0x890 net/sched/cls_u32.c:367 tcf_proto_create net/sched/cls_api.c:166 [inline] tc_ctl_tfilter+0xde3/0x1c10 net/sched/cls_api.c:677 rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4320 netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2435 netlink_unicast_kernel net/netlink/af_netlink.c:1289 [inline] netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1315 netlink_sendmsg+0x62e/0xb80 net/netlink/af_netlink.c:1880 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xb5/0x100 net/socket.c:656 ___sys_sendmsg+0x326/0x800 net/socket.c:2062 __sys_sendmmsg+0x129/0x330 net/socket.c:2152 SYSC_sendmmsg net/socket.c:2183 [inline] SyS_sendmmsg+0x2f/0x50 net/socket.c:2178 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 10120: 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 __rcu_reclaim kernel/rcu/rcu.h:190 [inline] rcu_do_batch kernel/rcu/tree.c:2699 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2962 [inline] __rcu_process_callbacks kernel/rcu/tree.c:2929 [inline] rcu_process_callbacks+0x88b/0x1180 kernel/rcu/tree.c:2946 __do_softirq+0x24d/0x9ff kernel/softirq.c:288 The buggy address belongs to the object at ffff8880af751600 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 24 bytes inside of 64-byte region [ffff8880af751600, ffff8880af751640) The buggy address belongs to the page: page:ffffea0002bdd440 count:1 mapcount:0 mapping:ffff8880af751000 index:0x0 flags: 0xfff00000000100(slab) raw: 00fff00000000100 ffff8880af751000 0000000000000000 0000000100000020 raw: ffffea00028c1120 ffffea000289cbe0 ffff88813fe80340 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880af751500: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc ffff8880af751580: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8880af751600: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff8880af751680: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc ffff8880af751700: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ================================================================== FAT-fs (loop4): Invalid FSINFO signature: 0x00000000, 0x00000000 (sector = 1)