6.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jiayuan Chen <mrpre@xxxxxxx>
[ Upstream commit 8ca2a1eeadf09862190b2810697702d803ceef2d ]
When the stream_verdict program returns SK_PASS, it places the received skb
into its own receive queue, but a recursive lock eventually occurs, leading
to an operating system deadlock. This issue has been present since v6.9.
'''
sk_psock_strp_data_ready
write_lock_bh(&sk->sk_callback_lock)
strp_data_ready
strp_read_sock
read_sock -> tcp_read_sock
strp_recv
cb.rcv_msg -> sk_psock_strp_read
# now stream_verdict return SK_PASS without peer sock assign
__SK_PASS = sk_psock_map_verd(SK_PASS, NULL)
sk_psock_verdict_apply
sk_psock_skb_ingress_self
sk_psock_skb_ingress_enqueue
sk_psock_data_ready
read_lock_bh(&sk->sk_callback_lock) <= dead lock
'''
This topic has been discussed before, but it has not been fixed.
Previous discussion:
https://lore.kernel.org/all/6684a5864ec86_403d20898@john.notmuch
Fixes: 6648e613226e ("bpf, skmsg: Fix NULL pointer dereference in sk_psock_skb_ingress_enqueue")
Reported-by: Vincent Whitchurch <vincent.whitchurch@xxxxxxxxxxxxx>
Signed-off-by: Jiayuan Chen <mrpre@xxxxxxx>
Signed-off-by: John Fastabend <john.fastabend@xxxxxxxxx>
Acked-by: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
Link: https://patch.msgid.link/20241118030910.36230-2-mrpre@xxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/core/skmsg.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index b1dcbd3be89e1..e90fbab703b2d 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c
@@ -1117,9 +1117,9 @@ static void sk_psock_strp_data_ready(struct sock *sk)
if (tls_sw_has_ctx_rx(sk)) {
psock->saved_data_ready(sk);
} else {
- write_lock_bh(&sk->sk_callback_lock);
+ read_lock_bh(&sk->sk_callback_lock);
strp_data_ready(&psock->strp);
- write_unlock_bh(&sk->sk_callback_lock);
+ read_unlock_bh(&sk->sk_callback_lock);
}
}
rcu_read_unlock();
--
2.43.0
