netdev - [PATCH net] Fixing a bug in team driver due to incorrect 'unsigned int' to 'int' conversion

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Date:   Wed, 05 Oct 2016 09:06:04 -0400
From:   Alex Sidorenko <alexandre.sidorenko@....com>
To:     Eric Dumazet <eric.dumazet@...il.com>
Cc:     netdev@...r.kernel.org
Subject: [PATCH net] Fixing a bug in team driver due to incorrect 'unsigned  int' to 'int' conversion

Roundrobin runner of team driver uses 'unsigned int' variable to count the number of sent_packets.
Later it is passed to a subroutine team_num_to_port_index(struct team *team, int num) as
'num' and when we reach MAXINT (2**31-1), 'num' becomes negative.

This leads to using incorrect hash-bucket for port lookup and as a result, packets are dropped. The fix
consists of changing 'int num' to 'unsigned int num'. Testing of a fixed kernel shows that there
is no packet drop anymore.


Signed-off-by: Alex Sidorenko <alexandre.sidorenko@....com>

---
 include/linux/if_team.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/if_team.h b/include/linux/if_team.h
index 174f43f..c05216a 100644
--- a/include/linux/if_team.h
+++ b/include/linux/if_team.h
@@ -245,7 +245,7 @@ static inline struct team_port *team_get_port_by_index(struct team *team,
        return NULL;
 }
 
-static inline int team_num_to_port_index(struct team *team, int num)
+static inline int team_num_to_port_index(struct team *team, unsigned int num)
 {
        int en_port_count = ACCESS_ONCE(team->en_port_count);
 
-- 
2.7.4
 


-- 

------------------------------------------------------------------
Alex Sidorenko	email: asid@....com
ERT  Linux 	Hewlett-Packard Enterprise (Canada)
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