[PATCH 5.4 025/123] net: systemport: fix index check to avoid an array out of bounds access

From: Greg Kroah-Hartman
Date: Tue Mar 17 2020 - 07:01:38 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

[ Upstream commit c0368595c1639947839c0db8294ee96aca0b3b86 ]

Currently the bounds check on index is off by one and can lead to
an out of bounds access on array priv->filters_loc when index is
RXCHK_BRCM_TAG_MAX.

Fixes: bb9051a2b230 ("net: systemport: Add support for WAKE_FILTER")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/broadcom/bcmsysport.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/ethernet/broadcom/bcmsysport.c
+++ b/drivers/net/ethernet/broadcom/bcmsysport.c
@@ -2135,7 +2135,7 @@ static int bcm_sysport_rule_set(struct b
return -ENOSPC;

index = find_first_zero_bit(priv->filters, RXCHK_BRCM_TAG_MAX);
- if (index > RXCHK_BRCM_TAG_MAX)
+ if (index >= RXCHK_BRCM_TAG_MAX)
return -ENOSPC;

/* Location is the classification ID, and index is the position