The definition of macro MOTO_SROM_BUG is:
#define MOTO_SROM_BUG (lp->active == 8 && (get_unaligned_le32(
dev->dev_addr) & 0x00ffffff) == 0x3e0008)
and the if statement
if (MOTO_SROM_BUG) lp->active = 0;
using this macro indicates lp->active could be 8. If lp->active is 8 and
the second comparison of this macro is false. lp->active will remain 8 in:
lp->phy[lp->active].gep = (*p ? p : NULL); p += (2 * (*p) + 1);
lp->phy[lp->active].rst = (*p ? p : NULL); p += (2 * (*p) + 1);
lp->phy[lp->active].mc = get_unaligned_le16(p); p += 2;
lp->phy[lp->active].ana = get_unaligned_le16(p); p += 2;
lp->phy[lp->active].fdx = get_unaligned_le16(p); p += 2;
lp->phy[lp->active].ttm = get_unaligned_le16(p); p += 2;
lp->phy[lp->active].mci = *p;
However, the length of array lp->phy is 8, so array overflows can occur.
To fix these possible array overflows, we first check lp->active and then
set it to 0 if it is equal to DE4X5_MAX_PHY (i.e., 8).
Reported-by: TOTE Robot <oslab@xxxxxxxxxxxxxxx>
Signed-off-by: Teng Qi <starmiku1207184332@xxxxxxxxx>
---
drivers/net/ethernet/dec/tulip/de4x5.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/dec/tulip/de4x5.c b/drivers/net/ethernet/dec/tulip/de4x5.c
index 13121c4dcfe6..18132deac2bf 100644
--- a/drivers/net/ethernet/dec/tulip/de4x5.c
+++ b/drivers/net/ethernet/dec/tulip/de4x5.c
@@ -4708,7 +4708,8 @@ type3_infoblock(struct net_device *dev, u_char count, u_char *p)
if (lp->state == INITIALISED) {
lp->ibn = 3;
lp->active = *p++;
- if (MOTO_SROM_BUG) lp->active = 0;
+ /* The DE4X5_MAX_PHY is length of lp->phy, and its value is 8 */
+ if (MOTO_SROM_BUG || lp->active == DE4X5_MAX_PHY) lp->active = 0;
lp->phy[lp->active].gep = (*p ? p : NULL); p += (2 * (*p) + 1);
lp->phy[lp->active].rst = (*p ? p : NULL); p += (2 * (*p) + 1);
lp->phy[lp->active].mc = get_unaligned_le16(p); p += 2;
--
2.25.1
