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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 ffff888053551eb8 by task syz-executor.4/24580

CPU: 0 PID: 24580 Comm: syz-executor.4 Not tainted 5.6.0-rc4-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_32_irqs_on arch/x86/entry/common.c:337 [inline]
 do_fast_syscall_32+0x270/0xe8f arch/x86/entry/common.c:408
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

Allocated by task 24583:
 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]
 call_usermodehelper_setup+0x98/0x300 kernel/umh.c:386
 call_modprobe kernel/kmod.c:94 [inline]
 __request_module+0x456/0xbab kernel/kmod.c:171
 __sock_create+0x557/0x730 net/socket.c:1414
 sock_create net/socket.c:1484 [inline]
 __sys_socket+0xef/0x200 net/socket.c:1526
 __do_sys_socket net/socket.c:1535 [inline]
 __se_sys_socket net/socket.c:1533 [inline]
 __ia32_sys_socket+0x6f/0xb0 net/socket.c:1533
 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
 do_fast_syscall_32+0x270/0xe8f arch/x86/entry/common.c:408
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

Freed by task 24583:
 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
 call_usermodehelper_freeinfo kernel/umh.c:48 [inline]
 call_usermodehelper_exec+0x242/0x4d0 kernel/umh.c:598
 call_modprobe kernel/kmod.c:99 [inline]
 __request_module+0x475/0xbab kernel/kmod.c:171
 __sock_create+0x557/0x730 net/socket.c:1414
 sock_create net/socket.c:1484 [inline]
 __sys_socket+0xef/0x200 net/socket.c:1526
 __do_sys_socket net/socket.c:1535 [inline]
 __se_sys_socket net/socket.c:1533 [inline]
 __ia32_sys_socket+0x6f/0xb0 net/socket.c:1533
 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline]
 do_fast_syscall_32+0x270/0xe8f arch/x86/entry/common.c:408
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139

The buggy address belongs to the object at ffff888053551e00
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 184 bytes inside of
 192-byte region [ffff888053551e00, ffff888053551ec0)
The buggy address belongs to the page:
page:ffffea00014d5440 refcount:1 mapcount:0 mapping:ffff8880aa000000 index:0x0
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea0002363948 ffffea00014fec88 ffff8880aa000000
raw: 0000000000000000 ffff888053551000 0000000100000010 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888053551d80: 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888053551e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888053551e80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                                        ^
 ffff888053551f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888053551f80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
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