syzbot

audit: type=1400 audit(1589147950.113:8): avc:  denied  { execmem } for  pid=6340 comm="syz-executor271" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1
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BUG: KASAN: null-ptr-deref in memset include/linux/string.h:332 [inline]
BUG: KASAN: null-ptr-deref in choke_reset+0x1fc/0x330 net/sched/sch_choke.c:330
Write of size 8 at addr           (null) by task syz-executor271/6340

CPU: 0 PID: 6340 Comm: syz-executor271 Not tainted 4.14.180-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x13e/0x194 lib/dump_stack.c:58
 kasan_report_error mm/kasan/report.c:349 [inline]
 kasan_report mm/kasan/report.c:409 [inline]
 kasan_report.cold+0x127/0x2ae mm/kasan/report.c:393
 memset+0x20/0x40 mm/kasan/kasan.c:285
 memset include/linux/string.h:332 [inline]
 choke_reset+0x1fc/0x330 net/sched/sch_choke.c:330
 qdisc_reset+0x61/0x1e0 net/sched/sch_generic.c:678
 dev_deactivate_queue.constprop.0+0xc5/0x150 net/sched/sch_generic.c:867
 netdev_for_each_tx_queue include/linux/netdevice.h:1970 [inline]
 dev_deactivate_many+0xd6/0x960 net/sched/sch_generic.c:922
 dev_deactivate+0xe2/0x190 net/sched/sch_generic.c:955
 qdisc_graft+0x989/0xcd0 net/sched/sch_api.c:919
 tc_modify_qdisc+0x99e/0x1181 net/sched/sch_api.c:1446
 rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4315
 netlink_rcv_skb+0x127/0x370 net/netlink/af_netlink.c:2433
 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline]
 netlink_unicast+0x437/0x620 net/netlink/af_netlink.c:1313
 netlink_sendmsg+0x733/0xbe0 net/netlink/af_netlink.c:1878
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xc5/0x100 net/socket.c:656
 ___sys_sendmsg+0x70a/0x840 net/socket.c:2062
 __sys_sendmsg+0xa3/0x120 net/socket.c:2096
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0x27/0x40 net/socket.c:2103
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x440719
RSP: 002b:00007ffd0563b2c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 0000000000440719
RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 0000000000000006
RBP: 0000000000000001 R08: 00000000ffffffff R09: 00000000004002c8
R10: 00000000ffffffff R11: 0000000000000246 R12: 0000000000007166
R13: 0000000000402030 R14: 0000000000000000 R15: 0000000000000000
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