[PATCH net-next 1/3] net-timestamp: add strict check when setting tx flags

[Jason Xing <kerneljasonxing@gmail.com>]

From: Jason Xing <kernelxing@tencent.com>

Even though this case is unlikely to happen, we have to avoid such
a case occurring at an earlier point: the sk_rmem_alloc could get
increased because of inserting more and more skbs into the errqueue
when calling __skb_complete_tx_timestamp(). This bad case would stop
the socket transmitting soon.

Signed-off-by: Jason Xing <kernelxing@tencent.com>
---
 net/core/sock.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/net/core/sock.c b/net/core/sock.c
index fe87f9bd8f16..4bddd6f62e4f 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -905,6 +905,10 @@ int sock_set_timestamping(struct sock *sk, int optname,
 	if (val & ~SOF_TIMESTAMPING_MASK)
 		return -EINVAL;
 
+	if (val & SOF_TIMESTAMPING_TX_RECORD_MASK &&
+	    !(val & SOF_TIMESTAMPING_SOFTWARE))
+		return -EINVAL;
+
 	if (val & SOF_TIMESTAMPING_OPT_ID_TCP &&
 	    !(val & SOF_TIMESTAMPING_OPT_ID))
 		return -EINVAL;
-- 
2.37.3