============================= 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: syz-executor.1 (10283): drop_caches: 2 rcu_scheduler_active = 2, debug_locks = 1 1 lock held by syz-executor.3/10264: #0: (rtnl_mutex){+.+.}, at: [] rtnl_lock net/core/rtnetlink.c:72 [inline] #0: (rtnl_mutex){+.+.}, at: [] rtnetlink_rcv_msg+0x31d/0xb10 net/core/rtnetlink.c:4317 stack backtrace: CPU: 0 PID: 10264 Comm: syz-executor.3 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: 0033:0x7f4dbf0460f9 RSP: 002b:00007f4dbd5b8168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f4dbf165f80 RCX: 00007f4dbf0460f9 RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000003 RBP: 00007f4dbf0a1ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd6da9697f R14: 00007f4dbd5b8300 R15: 0000000000022000 syz-executor.1 (10283): drop_caches: 2 FAT-fs (loop4): mounting with "discard" option, but the device does not support discard syz-executor.1 (10316): drop_caches: 2 syz-executor.1 (10316): drop_caches: 2 FAT-fs (loop4): mounting with "discard" option, but the device does not support discard syz-executor.2 (10338): drop_caches: 2 syz-executor.2 (10338): drop_caches: 2 syz-executor.1 (10340): drop_caches: 2 syz-executor.1 (10340): drop_caches: 2 syz-executor.5 (10337): drop_caches: 2 syz-executor.5 (10337): drop_caches: 2 syz-executor.1 (10348): drop_caches: 2 syz-executor.1 (10348): drop_caches: 2 syz-executor.2 (10351): drop_caches: 2 syz-executor.2 (10351): drop_caches: 2 FAT-fs (loop4): mounting with "discard" option, but the device does not support discard