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BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:56 [inline]
BUG: KASAN: null-ptr-deref in atomic_read include/asm-generic/atomic-instrumented.h:27 [inline]
BUG: KASAN: null-ptr-deref in tcf_idr_release_unsafe net/sched/act_api.c:279 [inline]
BUG: KASAN: null-ptr-deref in tcf_del_walker net/sched/act_api.c:310 [inline]
BUG: KASAN: null-ptr-deref in tcf_generic_walker+0x730/0xb60 net/sched/act_api.c:339
Read of size 4 at addr 0000000000000010 by task syz-executor.3/8290

CPU: 1 PID: 8290 Comm: syz-executor.3 Not tainted 5.9.0-rc3-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+0x198/0x1fd lib/dump_stack.c:118
 __kasan_report mm/kasan/report.c:517 [inline]
 kasan_report.cold+0x5/0x37 mm/kasan/report.c:530
 check_memory_region_inline mm/kasan/generic.c:186 [inline]
 check_memory_region+0x13d/0x180 mm/kasan/generic.c:192
 instrument_atomic_read include/linux/instrumented.h:56 [inline]
 atomic_read include/asm-generic/atomic-instrumented.h:27 [inline]
 tcf_idr_release_unsafe net/sched/act_api.c:279 [inline]
 tcf_del_walker net/sched/act_api.c:310 [inline]
 tcf_generic_walker+0x730/0xb60 net/sched/act_api.c:339
 tca_action_flush+0x42b/0x920 net/sched/act_api.c:1292
 tca_action_gd+0x8ac/0xda0 net/sched/act_api.c:1399
 tc_ctl_action+0x280/0x439 net/sched/act_api.c:1526
 rtnetlink_rcv_msg+0x44e/0xad0 net/core/rtnetlink.c:5563
 netlink_rcv_skb+0x15a/0x430 net/netlink/af_netlink.c:2470
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x856/0xd90 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:671
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2353
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2407
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2440
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d5f9
Code: 5d b4 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 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f7720fe6c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000002cf40 RCX: 000000000045d5f9
RDX: 0000000000000000 RSI: 0000000020002980 RDI: 0000000000000004
RBP: 000000000118d020 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec
R13: 00007ffeb835ee7f R14: 00007f7720fe79c0 R15: 000000000118cfec
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