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From: Frank Sorenson <sorenson@redhat.com>
To: linux-nfs@vger.kernel.org
Subject: [PATCH 1/3] sunrpc: Fix reserved port range calculation
Date: Fri,  8 Jul 2016 16:35:23 -0500	[thread overview]
Message-ID: <1468013725-22835-2-git-send-email-sorenson@redhat.com> (raw)
In-Reply-To: <1468013725-22835-1-git-send-email-sorenson@redhat.com>

The range calculation for choosing the random reserved port will panic
with divide-by-zero when min_resvport == max_resvport, a range of one
port, not zero.

Fix the reserved port range calculation by adding one to the difference.

Signed-off-by: Frank Sorenson <sorenson@redhat.com>
---
 net/sunrpc/xprtsock.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 7e2b2fa..1adda71 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -1714,7 +1714,7 @@ static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
 
 static unsigned short xs_get_random_port(void)
 {
-	unsigned short range = xprt_max_resvport - xprt_min_resvport;
+	unsigned short range = xprt_max_resvport - xprt_min_resvport + 1;
 	unsigned short rand = (unsigned short) prandom_u32() % range;
 	return rand + xprt_min_resvport;
 }
-- 
2.5.5


  reply	other threads:[~2016-07-08 21:35 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-07-08 21:35 [PATCH 0/3] sunrpc: Fix reserved port range calculation and possible panic Frank Sorenson
2016-07-08 21:35 ` Frank Sorenson [this message]
2016-07-08 21:35 ` [PATCH 2/3] sunrpc: Prevent resvport min/max inversion via sysctl Frank Sorenson
2016-07-08 21:35 ` [PATCH 3/3] sunrpc: Prevent resvport min/max inversion via sysfs and module parameter Frank Sorenson

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