sctp: check the rto_min and rto_max in setsockopt

When we set 0 to rto_min or rto_max, just not change the value. Also
we should check the rto_min > rto_max.

Suggested-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Wang Weidong <wangweidong1@huawei.com>
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 22 insertions, 10 deletions

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 5455043f4496..42b709c95cf3 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -2815,6 +2815,8 @@ static int sctp_setsockopt_rtoinfo(struct sock *sk, char __user *optval, unsigne
 {
         struct sctp_rtoinfo rtoinfo;
         struct sctp_association *asoc;
+        unsigned long rto_min, rto_max;
+        struct sctp_sock *sp = sctp_sk(sk);
 
         if (optlen != sizeof (struct sctp_rtoinfo))
                 return -EINVAL;
@@ -2828,26 +2830,36 @@ static int sctp_setsockopt_rtoinfo(struct sock *sk, char __user *optval, unsigne
         if (!asoc && rtoinfo.srto_assoc_id && sctp_style(sk, UDP))
                 return -EINVAL;
 
+        rto_max = rtoinfo.srto_max;
+        rto_min = rtoinfo.srto_min;
+
+        if (rto_max)
+                rto_max = asoc ? msecs_to_jiffies(rto_max) : rto_max;
+        else
+                rto_max = asoc ? asoc->rto_max : sp->rtoinfo.srto_max;
+
+        if (rto_min)
+                rto_min = asoc ? msecs_to_jiffies(rto_min) : rto_min;
+        else
+                rto_min = asoc ? asoc->rto_min : sp->rtoinfo.srto_min;
+
+        if (rto_min > rto_max)
+                return -EINVAL;
+
         if (asoc) {
                 if (rtoinfo.srto_initial != 0)
                         asoc->rto_initial =
                                 msecs_to_jiffies(rtoinfo.srto_initial);
-                if (rtoinfo.srto_max != 0)
-                        asoc->rto_max = msecs_to_jiffies(rtoinfo.srto_max);
-                if (rtoinfo.srto_min != 0)
-                        asoc->rto_min = msecs_to_jiffies(rtoinfo.srto_min);
+                asoc->rto_max = rto_max;
+                asoc->rto_min = rto_min;
         } else {
                 /* If there is no association or the association-id = 0
                  * set the values to the endpoint.
                  */
-                struct sctp_sock *sp = sctp_sk(sk);
-
                 if (rtoinfo.srto_initial != 0)
                         sp->rtoinfo.srto_initial = rtoinfo.srto_initial;
-                if (rtoinfo.srto_max != 0)
-                        sp->rtoinfo.srto_max = rtoinfo.srto_max;
-                if (rtoinfo.srto_min != 0)
-                        sp->rtoinfo.srto_min = rtoinfo.srto_min;
+                sp->rtoinfo.srto_max = rto_max;
+                sp->rtoinfo.srto_min = rto_min;
         }
 
         return 0;