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a6a5e87b3e
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>
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