============================= WARNING: suspicious RCU usage 5.16.0-rc8-syzkaller #0 Not tainted ----------------------------- include/linux/netfilter_netdev.h:97 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by syz-executor.5/5341: #0: ffffffff8bb83d40 (rcu_read_lock_bh){....}-{1:2}, at: lwtunnel_xmit_redirect include/net/lwtunnel.h:95 [inline] #0: ffffffff8bb83d40 (rcu_read_lock_bh){....}-{1:2}, at: ip_finish_output2+0x28c/0x2160 net/ipv4/ip_output.c:207 #1: ffffffff8bb83d40 (rcu_read_lock_bh){....}-{1:2}, at: __dev_queue_xmit+0x1e3/0x3650 net/core/dev.c:4153 stack backtrace: CPU: 0 PID: 5341 Comm: syz-executor.5 Not tainted 5.16.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nf_hook_egress include/linux/netfilter_netdev.h:97 [inline] __dev_queue_xmit+0x2ec3/0x3650 net/core/dev.c:4170 neigh_hh_output include/net/neighbour.h:511 [inline] neigh_output include/net/neighbour.h:525 [inline] ip_finish_output2+0x14cb/0x2160 net/ipv4/ip_output.c:221 __ip_finish_output net/ipv4/ip_output.c:299 [inline] __ip_finish_output+0x396/0x640 net/ipv4/ip_output.c:281 ip_finish_output+0x32/0x200 net/ipv4/ip_output.c:309 NF_HOOK_COND include/linux/netfilter.h:296 [inline] ip_output+0x196/0x310 net/ipv4/ip_output.c:423 dst_output include/net/dst.h:450 [inline] NF_HOOK include/linux/netfilter.h:307 [inline] raw_send_hdrinc net/ipv4/raw.c:429 [inline] raw_sendmsg+0x1d88/0x2e50 net/ipv4/raw.c:660 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 sock_no_sendpage+0xf6/0x140 net/core/sock.c:3080 inet_sendpage+0x103/0x140 net/ipv4/af_inet.c:834 kernel_sendpage.part.0+0x1a0/0x340 net/socket.c:3504 kernel_sendpage net/socket.c:3501 [inline] sock_sendpage+0xe5/0x140 net/socket.c:1003 pipe_to_sendpage+0x2ad/0x380 fs/splice.c:364 splice_from_pipe_feed fs/splice.c:418 [inline] __splice_from_pipe+0x43e/0x8a0 fs/splice.c:562 splice_from_pipe fs/splice.c:597 [inline] generic_splice_sendpage+0xd4/0x140 fs/splice.c:746 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x110/0x180 fs/splice.c:936 splice_direct_to_actor+0x34b/0x8c0 fs/splice.c:891 do_splice_direct+0x1b3/0x280 fs/splice.c:979 do_sendfile+0xaf2/0x1250 fs/read_write.c:1245 __do_sys_sendfile64 fs/read_write.c:1310 [inline] __se_sys_sendfile64 fs/read_write.c:1296 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1296 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f2a86077e99 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2a849ed168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f2a8618af60 RCX: 00007f2a86077e99 RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000006 RBP: 00007f2a860d1ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 4000000000000081 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2a866beb1f R14: 00007f2a849ed300 R15: 0000000000022000