Re: [PATCH] bonding: alb: Fix overflow in TLB gap calculation

From: Li RongQing <redacted>

compute_gap() shifts 32-bit values before converting them to s64,
which can overflow for high speed network devices. The overflowed
value is then incorrectly used in the TLB load balancing calculation.

Convert the operands to s64 before shifting so the arithmetic is done
in 64-bit width.

Fixes: 097811bb48c7 ("bonding: optimize tlb_get_least_loaded_slave")
Cc: stable@vger.kernel.org
Signed-off-by: Li RongQing <redacted>
---
  drivers/net/bonding/bond_alb.c | 4 ++--
  1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/bonding/bond_alb.c b/drivers/net/bonding/bond_alb.c
index 43ac8e2..b520040 100644
--- a/drivers/net/bonding/bond_alb.c
+++ b/drivers/net/bonding/bond_alb.c

@@ -160,8 +160,8 @@ static void tlb_deinitialize(struct bonding *bond)
  
  static long long compute_gap(struct slave *slave)
  {
-	return (s64) (slave->speed << 20) - /* Convert to Megabit per sec */
-	       (s64) (SLAVE_TLB_INFO(slave).load << 3); /* Bytes to bits */
+	return ((s64)slave->speed << 20) - /* Convert to Megabit per sec */
+	       ((s64)SLAVE_TLB_INFO(slave).load << 3); /* Bytes to bits */
  }
  
  static struct slave *tlb_get_least_loaded_slave(struct bonding *bond)