============================= WARNING: suspicious RCU usage 4.14.307-syzkaller #0 Not tainted ----------------------------- net/sched/act_sample.c:95 suspicious rcu_dereference_protected() usage! ufs: ufs was compiled with read-only support, can't be mounted as read-write other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 print_req_error: I/O error, dev loop1, sector 0 1 lock held by syz-executor.1/9816: #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: 9816 Comm: syz-executor.1 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: 0033:0x7f9e4164c0f9 RSP: 002b:00007f9e3fbbe168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f9e4176bf80 RCX: 00007f9e4164c0f9 RDX: 0000000000000000 RSI: 0000000020002980 RDI: 0000000000000003 RBP: 00007f9e416a7ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffee8509daf R14: 00007f9e3fbbe300 R15: 0000000000022000 ufs: ufs was compiled with read-only support, can't be mounted as read-write print_req_error: I/O error, dev loop1, sector 0 ufs: ufs was compiled with read-only support, can't be mounted as read-write EXT4-fs: Warning: mounting with data=journal disables delayed allocation and O_DIRECT support! EXT4-fs warning (device loop1): ext4_update_dynamic_rev:793: updating to rev 1 because of new feature flag, running e2fsck is recommended EXT4-fs error (device loop1): ext4_orphan_get:1265: comm syz-executor.1: bad orphan inode 15 ext4_test_bit(bit=14, block=18) = 1 is_bad_inode(inode)=0 NEXT_ORPHAN(inode)=4294967295 max_ino=32 i_nlink=0 EXT4-fs error (device loop1) in ext4_do_update_inode:5315: error 27 EXT4-fs error (device loop1) in ext4_do_update_inode:5315: error 27 EXT4-fs error (device loop1): ext4_xattr_delete_inode:2948: inode #15: comm syz-executor.1: mark inode dirty (error -27) EXT4-fs warning (device loop1): ext4_evict_inode:317: xattr delete (err -27) EXT4-fs (loop1): mounted filesystem without journal. Opts: acl,grpquota,,errors=continue Zero length message leads to an empty skb autofs4:pid:10371:validate_dev_ioctl: path string terminator missing for cmd(0xc018937c) unregister_netdevice: waiting for ip6gre0 to become free. Usage count = -1 mmap: syz-executor.1 (10546) uses deprecated remap_file_pages() syscall. See Documentation/vm/remap_file_pages.txt. L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details.