From 56ac11cf2f21366ad48b356f7a0d1af8cff3588e Mon Sep 17 00:00:00 2001 From: Radu Iliescu Date: Thu, 19 Jan 2012 03:57:57 +0000 Subject: [PATCH] llc: Fix race condition in llc_ui_recvmsg There is a race on sk_receive_queue between llc_ui_recvmsg and sock_queue_rcv_skb. Our current solution is to protect skb_eat in llc_ui_recvmsg with the queue spinlock. Signed-off-by: Radu Iliescu Signed-off-by: David S. Miller --- net/llc/af_llc.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c index a18e6c3d36e3..b9bef2c75026 100644 --- a/net/llc/af_llc.c +++ b/net/llc/af_llc.c @@ -713,6 +713,7 @@ static int llc_ui_recvmsg(struct kiocb *iocb, struct socket *sock, struct sk_buff *skb = NULL; struct sock *sk = sock->sk; struct llc_sock *llc = llc_sk(sk); + unsigned long cpu_flags; size_t copied = 0; u32 peek_seq = 0; u32 *seq; @@ -838,7 +839,9 @@ static int llc_ui_recvmsg(struct kiocb *iocb, struct socket *sock, goto copy_uaddr; if (!(flags & MSG_PEEK)) { + spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags); sk_eat_skb(sk, skb, 0); + spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags); *seq = 0; } @@ -859,7 +862,9 @@ copy_uaddr: llc_cmsg_rcv(msg, skb); if (!(flags & MSG_PEEK)) { + spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags); sk_eat_skb(sk, skb, 0); + spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags); *seq = 0; } -- 2.30.2