[PATCH 4.9 022/144] netfilter: ipset: List timing out entries with "timeout 1" instead of zero

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jozsef Kadlecsik <kadlec@xxxxxxxxxxxxxxxxx>

[ Upstream commit bd975e691486ba52790ba23cc9b4fecab7bc0d31 ]

When listing sets with timeout support, there's a probability that
just timing out entries with "0" timeout value is listed/saved.
However when restoring the saved list, the zero timeout value means
permanent elelements.

The new behaviour is that timing out entries are listed with "timeout 1"
instead of zero.

Fixes netfilter bugzilla #1258.

Signed-off-by: Jozsef Kadlecsik <kadlec@xxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 include/linux/netfilter/ipset/ip_set_timeout.h |   10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

--- a/include/linux/netfilter/ipset/ip_set_timeout.h
+++ b/include/linux/netfilter/ipset/ip_set_timeout.h
@@ -65,8 +65,14 @@ ip_set_timeout_set(unsigned long *timeou
 static inline u32
 ip_set_timeout_get(unsigned long *timeout)
 {
-	return *timeout == IPSET_ELEM_PERMANENT ? 0 :
-		jiffies_to_msecs(*timeout - jiffies)/MSEC_PER_SEC;
+	u32 t;
+
+	if (*timeout == IPSET_ELEM_PERMANENT)
+		return 0;
+
+	t = jiffies_to_msecs(*timeout - jiffies)/MSEC_PER_SEC;
+	/* Zero value in userspace means no timeout */
+	return t == 0 ? 1 : t;
 }
 
 #endif	/* __KERNEL__ */