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BUG: KASAN: null-ptr-deref in memset include/linux/string.h:333 [inline]
BUG: KASAN: null-ptr-deref in choke_reset+0x208/0x340 net/sched/sch_choke.c:330
Write of size 8 at addr 0000000000000000 by task syz-executor.5/16310

CPU: 0 PID: 16310 Comm: syz-executor.5 Not tainted 4.19.121-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
 kasan_report_error mm/kasan/report.c:352 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold+0x194/0x2b9 mm/kasan/report.c:396
 memset+0x20/0x40 mm/kasan/kasan.c:285
 memset include/linux/string.h:333 [inline]
 choke_reset+0x208/0x340 net/sched/sch_choke.c:330
 qdisc_destroy+0x144/0x6b0 net/sched/sch_generic.c:980
 notify_and_destroy+0x93/0xb0 net/sched/sch_api.c:924
 qdisc_graft+0xa74/0xf90 net/sched/sch_api.c:982
 tc_modify_qdisc+0xb9c/0x1929 net/sched/sch_api.c:1582
 rtnetlink_rcv_msg+0x453/0xaf0 net/core/rtnetlink.c:4777
 netlink_rcv_skb+0x160/0x410 net/netlink/af_netlink.c:2455
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x4d7/0x6a0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x80b/0xcd0 net/netlink/af_netlink.c:1909
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:632
 ___sys_sendmsg+0x803/0x920 net/socket.c:2115
 __sys_sendmsg+0xec/0x1b0 net/socket.c:2153
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c829
Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f537aaa2c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000500d20 RCX: 000000000045c829
RDX: 0000000000000000 RSI: 0000000020000800 RDI: 0000000000000005
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000a05 R14: 00000000004ccbdd R15: 00007f537aaa36d4
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