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BUG: KASAN: null-ptr-deref in atomic_read include/asm-generic/atomic-instrumented.h:26 [inline]
BUG: KASAN: null-ptr-deref in tcf_idr_release_unsafe net/sched/act_api.c:277 [inline]
BUG: KASAN: null-ptr-deref in tcf_del_walker net/sched/act_api.c:308 [inline]
BUG: KASAN: null-ptr-deref in tcf_generic_walker+0x611/0xb30 net/sched/act_api.c:337
Read of size 4 at addr 0000000000000010 by task syz-executor711/8964

CPU: 0 PID: 8964 Comm: syz-executor711 Not tainted 5.5.0-rc7-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+0x1fb/0x318 lib/dump_stack.c:118
 __kasan_report+0x167/0x1c0 mm/kasan/report.c:510
 kasan_report+0x26/0x50 mm/kasan/common.c:639
 check_memory_region_inline mm/kasan/generic.c:182 [inline]
 check_memory_region+0x2b6/0x2f0 mm/kasan/generic.c:192
 __kasan_check_read+0x11/0x20 mm/kasan/common.c:95
 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline]
 tcf_idr_release_unsafe net/sched/act_api.c:277 [inline]
 tcf_del_walker net/sched/act_api.c:308 [inline]
 tcf_generic_walker+0x611/0xb30 net/sched/act_api.c:337
 tcf_ife_walker+0x4c/0x60 net/sched/act_ife.c:866
 tca_action_flush net/sched/act_api.c:1237 [inline]
 tca_action_gd+0x135a/0x18f0 net/sched/act_api.c:1344
 tc_ctl_action+0x3b7/0x810 net/sched/act_api.c:1473
 rtnetlink_rcv_msg+0x889/0xd40 net/core/rtnetlink.c:5433
 netlink_rcv_skb+0x19e/0x3e0 net/netlink/af_netlink.c:2477
 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5451
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0x767/0x920 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0xa2c/0xd50 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:639 [inline]
 sock_sendmsg net/socket.c:659 [inline]
 ____sys_sendmsg+0x4f7/0x7f0 net/socket.c:2330
 ___sys_sendmsg net/socket.c:2384 [inline]
 __sys_sendmsg+0x1ed/0x290 net/socket.c:2417
 __do_sys_sendmsg net/socket.c:2426 [inline]
 __se_sys_sendmsg net/socket.c:2424 [inline]
 __x64_sys_sendmsg+0x7f/0x90 net/socket.c:2424
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x446939
Code: e8 0c e8 ff ff 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 5b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f31803a8da8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 0000000000446939
RDX: 0000000000000000 RSI: 0000000020000300 RDI: 0000000000000003
RBP: 00000000006dbc20 R08: 0000000000000008 R09: 0000000000000000
R10: 000000000000000c R11: 0000000000000246 R12: 00000000006dbc2c
R13: 0000000020000400 R14: 00000000004ae7e8 R15: 000000000000002d
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