Antonio Quartulli a6a5e87b3e ovpn: avoid sleep in atomic context in TCP RX error path ... Upon error along the TCP data_ready event path, we have the following chain of calls: strp_data_ready() ovpn_tcp_rcv() ovpn_peer_del() ovpn_socket_release() Since strp_data_ready() may be invoked from softirq context, and ovpn_socket_release() may sleep, the above sequence may cause a sleep in atomic context like the following: BUG: sleeping function called from invalid context at ./ovpn-backports-ovpn-net-next-main-6.15.0-rc5-20250522/drivers/net/ovpn/socket.c:71 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 25, name: ksoftirqd/3 5 locks held by ksoftirqd/3/25: #0: ffffffe000cd0580 (rcu_read_lock){....}-{1:2}, at: netif_receive_skb+0xb8/0x5b0 OpenVPN/ovpn-backports#1: ffffffe000cd0580 (rcu_read_lock){....}-{1:2}, at: netif_receive_skb+0xb8/0x5b0 OpenVPN/ovpn-backports#2: ffffffe000cd0580 (rcu_read_lock){....}-{1:2}, at: ip_local_deliver_finish+0x66/0x1e0 OpenVPN/ovpn-backports#3: ffffffe003ce9818 (slock-AF_INET/1){+.-.}-{2:2}, at: tcp_v4_rcv+0x156e/0x17a0 OpenVPN/ovpn-backports#4: ffffffe000cd0580 (rcu_read_lock){....}-{1:2}, at: ovpn_tcp_data_ready+0x0/0x1b0 [ovpn] CPU: 3 PID: 25 Comm: ksoftirqd/3 Not tainted 5.10.104+ #0 Call Trace: walk_stackframe+0x0/0x1d0 show_stack+0x2e/0x44 dump_stack+0xc2/0x102 ___might_sleep+0x29c/0x2b0 __might_sleep+0x62/0xa0 ovpn_socket_release+0x24/0x2d0 [ovpn] unlock_ovpn+0x6e/0x190 [ovpn] ovpn_peer_del+0x13c/0x390 [ovpn] ovpn_tcp_rcv+0x280/0x560 [ovpn] __strp_recv+0x262/0x940 strp_recv+0x66/0x80 tcp_read_sock+0x122/0x410 strp_data_ready+0x156/0x1f0 ovpn_tcp_data_ready+0x92/0x1b0 [ovpn] tcp_data_ready+0x6c/0x150 tcp_rcv_established+0xb36/0xc50 tcp_v4_do_rcv+0x25e/0x380 tcp_v4_rcv+0x166a/0x17a0 ip_protocol_deliver_rcu+0x8c/0x250 ip_local_deliver_finish+0xf8/0x1e0 ip_local_deliver+0xc2/0x2d0 ip_rcv+0x1f2/0x330 __netif_receive_skb+0xfc/0x290 netif_receive_skb+0x104/0x5b0 br_pass_frame_up+0x190/0x3f0 br_handle_frame_finish+0x3e2/0x7a0 br_handle_frame+0x750/0xab0 __netif_receive_skb_core.constprop.0+0x4c0/0x17f0 __netif_receive_skb+0xc6/0x290 netif_receive_skb+0x104/0x5b0 xgmac_dma_rx+0x962/0xb40 __napi_poll.constprop.0+0x5a/0x350 net_rx_action+0x1fe/0x4b0 __do_softirq+0x1f8/0x85c run_ksoftirqd+0x80/0xd0 smpboot_thread_fn+0x1f0/0x3e0 kthread+0x1e6/0x210 ret_from_kernel_thread+0x8/0xc Fix this issue by postponing the ovpn_peer_del() call to a scheduled worker, as we already do in ovpn_tcp_send_sock() for the very same reason. Fixes: 11851cbd60 ("ovpn: implement TCP transport") Reported-by: Qingfang Deng <dqfext@gmail.com> Closes: https://github.com/OpenVPN/ovpn-net-next/issues/13 Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com> Signed-off-by: Antonio Quartulli <antonio@openvpn.net>		2025-06-03 13:08:15 +02:00
..
bind.c	ovpn: implement packet processing	2025-04-17 12:30:02 +02:00
bind.h	ovpn: introduce the ovpn_peer object	2025-04-17 12:30:02 +02:00
crypto_aead.c	ovpn: fix check for skb_to_sgvec_nomark() return value	2025-05-15 13:09:36 +02:00
crypto_aead.h	ovpn: implement key add/get/del/swap via netlink	2025-04-17 12:30:03 +02:00
crypto.c	ovpn: kill key and notify userspace in case of IV exhaustion	2025-04-17 12:30:03 +02:00
crypto.h	ovpn: kill key and notify userspace in case of IV exhaustion	2025-04-17 12:30:03 +02:00
io.c	ovpn: ensure sk is still valid during cleanup	2025-06-03 13:08:15 +02:00
io.h	ovpn: implement keepalive mechanism	2025-04-17 12:30:03 +02:00
main.c	ovpn: don't drop skb's dst when xmitting packet	2025-05-15 13:09:36 +02:00
main.h
Makefile	ovpn: implement TCP transport	2025-04-17 12:30:03 +02:00
netlink-gen.c
netlink-gen.h
netlink.c	ovpn: ensure sk is still valid during cleanup	2025-06-03 13:08:15 +02:00
netlink.h	ovpn: notify userspace when a peer is deleted	2025-04-17 12:30:03 +02:00
ovpnpriv.h	ovpn: implement keepalive mechanism	2025-04-17 12:30:03 +02:00
peer.c	ovpn: ensure sk is still valid during cleanup	2025-06-03 13:08:15 +02:00
peer.h	ovpn: implement peer add/get/dump/delete via netlink	2025-04-17 12:30:03 +02:00
pktid.c	ovpn: implement packet processing	2025-04-17 12:30:02 +02:00
pktid.h	ovpn: implement packet processing	2025-04-17 12:30:02 +02:00
proto.h	ovpn: implement packet processing	2025-04-17 12:30:02 +02:00
skb.h	ovpn: add support for MSG_NOSIGNAL in tcp_sendmsg	2025-04-17 12:30:03 +02:00
socket.c	ovpn: ensure sk is still valid during cleanup	2025-06-03 13:08:15 +02:00
socket.h	ovpn: ensure sk is still valid during cleanup	2025-06-03 13:08:15 +02:00
stats.c	ovpn: store tunnel and transport statistics	2025-04-17 12:30:02 +02:00
stats.h	ovpn: store tunnel and transport statistics	2025-04-17 12:30:02 +02:00
tcp.c	ovpn: avoid sleep in atomic context in TCP RX error path	2025-06-03 13:08:15 +02:00
tcp.h	ovpn: ensure sk is still valid during cleanup	2025-06-03 13:08:15 +02:00
udp.c	ovpn: ensure sk is still valid during cleanup	2025-06-03 13:08:15 +02:00
udp.h	ovpn: ensure sk is still valid during cleanup	2025-06-03 13:08:15 +02:00