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BUG: KASAN: use-after-free in tcindex_set_parms+0x17fd/0x1a00 net/sched/cls_tcindex.c:455
Write of size 16 at addr ffff8880a6d2ac30 by task syz-executor965/9599

CPU: 0 PID: 9599 Comm: syz-executor965 Not tainted 5.6.0-rc6-syzkaller #0
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+0x188/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:374
 __kasan_report.cold+0x1a/0x32 mm/kasan/report.c:506
 kasan_report+0xe/0x20 mm/kasan/common.c:641
 tcindex_set_parms+0x17fd/0x1a00 net/sched/cls_tcindex.c:455
 tcindex_change+0x203/0x2e0 net/sched/cls_tcindex.c:518
 tc_new_tfilter+0xa59/0x20b0 net/sched/cls_api.c:2103
 rtnetlink_rcv_msg+0x810/0xad0 net/core/rtnetlink.c:5427
 netlink_rcv_skb+0x15a/0x410 net/netlink/af_netlink.c:2478
 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
 netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329
 netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 ____sys_sendmsg+0x6b9/0x7d0 net/socket.c:2343
 ___sys_sendmsg+0x100/0x170 net/socket.c:2397
 __sys_sendmsg+0xec/0x1b0 net/socket.c:2430
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4416f9
Code: e8 5c ad 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 3b 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffc859d4398 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004416f9
RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000000000003
RBP: 00007ffc859d43a0 R08: 0000000120080522 R09: 0000000120080522
R10: 0000000120080522 R11: 0000000000000246 R12: 00000000004a2a30
R13: 0000000000402650 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 1361:
 save_stack+0x1b/0x80 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 __kasan_kmalloc mm/kasan/common.c:515 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:488
 kmem_cache_alloc_trace+0x153/0x7d0 mm/slab.c:3551
 kmalloc include/linux/slab.h:555 [inline]
 kzalloc include/linux/slab.h:669 [inline]
 kthread+0x96/0x430 kernel/kthread.c:224
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Freed by task 1:
 save_stack+0x1b/0x80 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 kasan_set_free_info mm/kasan/common.c:337 [inline]
 __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:476
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x109/0x2b0 mm/slab.c:3757
 free_task+0xe3/0x110 kernel/fork.c:475
 __put_task_struct+0x22d/0x520 kernel/fork.c:751
 put_task_struct include/linux/sched/task.h:122 [inline]
 delayed_put_task_struct+0x248/0x3b0 kernel/exit.c:182
 rcu_do_batch kernel/rcu/tree.c:2186 [inline]
 rcu_core+0x5a4/0x12d0 kernel/rcu/tree.c:2410
 __do_softirq+0x26c/0x99d kernel/softirq.c:292

The buggy address belongs to the object at ffff8880a6d2ac00
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 48 bytes inside of
 192-byte region [ffff8880a6d2ac00, ffff8880a6d2acc0)
The buggy address belongs to the page:
page:ffffea00029b4a80 refcount:1 mapcount:0 mapping:ffff8880aa000000 index:0x0
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea00029a6c48 ffffea00029972c8 ffff8880aa000000
raw: 0000000000000000 ffff8880a6d2a000 0000000100000010 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a6d2ab00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880a6d2ab80: 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880a6d2ac00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff8880a6d2ac80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8880a6d2ad00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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