=============================
WARNING: suspicious RCU usage
4.14.307-syzkaller #0 Not tainted
-----------------------------
net/sched/act_sample.c:95 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz-executor.5/10276:
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff85c8dcdd>] rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0:  (rtnl_mutex){+.+.}, at: [<ffffffff85c8dcdd>] rtnetlink_rcv_msg+0x31d/0xb10 net/core/rtnetlink.c:4317

stack backtrace:
CPU: 1 PID: 10276 Comm: syz-executor.5 Not tainted 4.14.307-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 tcf_sample_init+0x71c/0x8c0 net/sched/act_sample.c:95
 tcf_action_init_1+0x51a/0x9e0 net/sched/act_api.c:691
 tcf_action_init+0x26d/0x400 net/sched/act_api.c:760
 tcf_action_add net/sched/act_api.c:1088 [inline]
 tc_ctl_action+0x2e3/0x510 net/sched/act_api.c:1140
 rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4322
 netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2461
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1328
 netlink_sendmsg+0x651/0xbc0 net/netlink/af_netlink.c:1900
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xb5/0x100 net/socket.c:656
 ___sys_sendmsg+0x6c8/0x800 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+0x5e/0xd3
RIP: 0033:0x7fa61e2330f9
RSP: 002b:00007fa61c7a5168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fa61e352f80 RCX: 00007fa61e2330f9
RDX: 0000000000000000 RSI: 0000000020002980 RDI: 0000000000000004
RBP: 00007fa61e28eae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff5eacdf1f R14: 00007fa61c7a5300 R15: 0000000000022000
kauditd_printk_skb: 2 callbacks suppressed
audit: type=1804 audit(1677727302.780:14): pid=10342 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir1725164818/syzkaller.ZnUt06/24/bus" dev="sda1" ino=14001 res=1
audit: type=1804 audit(1677727302.800:15): pid=10343 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir1808312498/syzkaller.Ft6cP0/19/bus" dev="sda1" ino=14003 res=1
audit: type=1804 audit(1677727303.810:16): pid=10355 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir1808312498/syzkaller.Ft6cP0/20/bus" dev="sda1" ino=13906 res=1
audit: type=1804 audit(1677727304.340:17): pid=10359 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir1725164818/syzkaller.ZnUt06/25/bus" dev="sda1" ino=14007 res=1
audit: type=1804 audit(1677727305.420:18): pid=10378 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir2473691296/syzkaller.WyEnvl/27/bus" dev="sda1" ino=13998 res=1
audit: type=1804 audit(1677727305.440:19): pid=10379 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.4" name="/root/syzkaller-testdir1808312498/syzkaller.Ft6cP0/21/bus" dev="sda1" ino=14009 res=1
NILFS (loop4): segctord starting. Construction interval = 5 seconds, CP frequency < 30 seconds
audit: type=1804 audit(1677727306.390:20): pid=10394 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir2473691296/syzkaller.WyEnvl/28/bus" dev="sda1" ino=13998 res=1
audit: type=1804 audit(1677727307.330:21): pid=10418 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.2" name="/root/syzkaller-testdir2473691296/syzkaller.WyEnvl/29/bus" dev="sda1" ino=13999 res=1
audit: type=1804 audit(1677727308.190:22): pid=10443 uid=0 auid=4294967295 ses=4294967295 op="invalid_pcr" cause="open_writers" comm="syz-executor.5" name="/root/syzkaller-testdir1725164818/syzkaller.ZnUt06/26/bus" dev="sda1" ino=14014 res=1
FAT-fs (loop0): error, invalid access to FAT (entry 0x00000109)
FAT-fs (loop0): Filesystem has been set read-only
FAT-fs (loop0): error, invalid access to FAT (entry 0x00000109)
======================================================
WARNING: the mand mount option is being deprecated and
         will be removed in v5.15!
======================================================
F2FS-fs (loop1): Mismatch start address, segment0(512) cp_blkaddr(605)
F2FS-fs (loop1): Can't find valid F2FS filesystem in 1th superblock
F2FS-fs (loop1): invalid crc value
F2FS-fs (loop1): Found nat_bits in checkpoint
F2FS-fs (loop1): Mounted with checkpoint version = 753bd00b
FAT-fs (loop0): error, invalid access to FAT (entry 0x00000109)
FAT-fs (loop0): Filesystem has been set read-only
FAT-fs (loop0): error, invalid access to FAT (entry 0x00000109)
FAT-fs (loop0): error, invalid access to FAT (entry 0x00000109)
FAT-fs (loop0): Filesystem has been set read-only
unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1
FAT-fs (loop0): error, invalid access to FAT (entry 0x00000109)
FAT-fs (loop0): error, invalid access to FAT (entry 0x00000109)
FAT-fs (loop0): Filesystem has been set read-only