syzbot

netlink: 24 bytes leftover after parsing attributes in process `syz-executor432'.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor432'.
netlink: 24 bytes leftover after parsing attributes in process `syz-executor432'.
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BUG: KASAN: use-after-free in rhashtable_rehash_one lib/rhashtable.c:276 [inline]
BUG: KASAN: use-after-free in rhashtable_rehash_chain lib/rhashtable.c:316 [inline]
BUG: KASAN: use-after-free in rhashtable_rehash_table lib/rhashtable.c:364 [inline]
BUG: KASAN: use-after-free in rht_deferred_worker+0x1366/0x1890 lib/rhashtable.c:465
Read of size 8 at addr ffff8880a9470340 by task kworker/0:0/3

CPU: 0 PID: 3 Comm: kworker/0:0 Not tainted 4.14.223-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events rht_deferred_worker
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_load8_noabort+0x68/0x70 mm/kasan/report.c:430
 rhashtable_rehash_one lib/rhashtable.c:276 [inline]
 rhashtable_rehash_chain lib/rhashtable.c:316 [inline]
 rhashtable_rehash_table lib/rhashtable.c:364 [inline]
 rht_deferred_worker+0x1366/0x1890 lib/rhashtable.c:465
 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116
 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

Allocated by task 9731:
 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]
 fl_change+0x27e/0x4830 net/sched/cls_flower.c:919
 tc_ctl_tfilter+0xb54/0x1c10 net/sched/cls_api.c:738
 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
 ___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 22:
 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
 fl_destroy_filter_work+0x1a/0x20 net/sched/cls_flower.c:234
 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116
 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

The buggy address belongs to the object at ffff8880a9470340
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 0 bytes inside of
 512-byte region [ffff8880a9470340, ffff8880a9470540)
The buggy address belongs to the page:
page:ffffea0002a51c00 count:1 mapcount:0 mapping:ffff8880a94700c0 index:0x0
flags: 0xfff00000000100(slab)
raw: 00fff00000000100 ffff8880a94700c0 0000000000000000 0000000100000006
raw: ffffea00029557a0 ffffea00028c02a0 ffff88813fe80940 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a9470200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880a9470280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff8880a9470300: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                                           ^
 ffff8880a9470380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880a9470400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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