Re: [dpdk-dev] [PATCH] net/igc: fix memory illegal accesses

[Jeff Guo]

hi, alvin


On 5/7/2020 10:01 AM, alvinx.zh...@intel.com wrote:

From: Alvin Zhang <alvinx.zh...@intel.com>

Add memory access out-of-bounds check.

Could you explain why add ...?  If not add, what issue?

Fixes: bd3fcf0d0fa1 (net/igc: support RSS)
Cc: sta...@dpdk.org

Signed-off-by: Alvin Zhang <alvinx.zh...@intel.com>
---
  drivers/net/igc/igc_ethdev.c | 12 ++++++++++--
  1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/net/igc/igc_ethdev.c b/drivers/net/igc/igc_ethdev.c
index 16d98c6..ced8ffd 100644
--- a/drivers/net/igc/igc_ethdev.c
+++ b/drivers/net/igc/igc_ethdev.c
@@ -2266,6 +2266,8 @@ static int eth_igc_vlan_tpid_set(struct rte_eth_dev *dev,
                return -EINVAL;
        }

+ RTE_BUILD_BUG_ON(ETH_RSS_RETA_SIZE_128 % IGC_RSS_RDT_REG_SIZE);

+
        /* set redirection table */
        for (i = 0; i < ETH_RSS_RETA_SIZE_128; i += IGC_RSS_RDT_REG_SIZE) {
                union igc_rss_reta_reg reta, reg;
@@ -2278,7 +2280,8 @@ static int eth_igc_vlan_tpid_set(struct rte_eth_dev *dev,
                                IGC_RSS_RDT_REG_SIZE_MASK);

/* if no need to update the register */

-               if (!mask)
+               if (!mask ||
+                       shift > (RTE_RETA_GROUP_SIZE - IGC_RSS_RDT_REG_SIZE))

alignment should be match above parentheses.

                        continue;

/* check mask whether need to read the register value first */

@@ -2289,6 +2292,7 @@ static int eth_igc_vlan_tpid_set(struct rte_eth_dev *dev,
                                        IGC_RETA(i / IGC_RSS_RDT_REG_SIZE));

/* update the register */

+               RTE_BUILD_BUG_ON(sizeof(reta.bytes) != IGC_RSS_RDT_REG_SIZE);
                for (j = 0; j < IGC_RSS_RDT_REG_SIZE; j++) {
                        if (mask & (1u << j))
                                reta.bytes[j] =
@@ -2318,6 +2322,8 @@ static int eth_igc_vlan_tpid_set(struct rte_eth_dev *dev,
                return -EINVAL;
        }

+ RTE_BUILD_BUG_ON(ETH_RSS_RETA_SIZE_128 % IGC_RSS_RDT_REG_SIZE);

+
        /* read redirection table */
        for (i = 0; i < ETH_RSS_RETA_SIZE_128; i += IGC_RSS_RDT_REG_SIZE) {
                union igc_rss_reta_reg reta;
@@ -2330,12 +2336,14 @@ static int eth_igc_vlan_tpid_set(struct rte_eth_dev 
*dev,
                                IGC_RSS_RDT_REG_SIZE_MASK);

/* if no need to read register */

-               if (!mask)
+               if (!mask ||
+                       shift > (RTE_RETA_GROUP_SIZE - IGC_RSS_RDT_REG_SIZE))

the same as above.

                        continue;

/* read register and get the queue index */

                reta.dword = IGC_READ_REG_LE_VALUE(hw,
                                IGC_RETA(i / IGC_RSS_RDT_REG_SIZE));
+               RTE_BUILD_BUG_ON(sizeof(reta.bytes) != IGC_RSS_RDT_REG_SIZE);

need null line or no need, please check it at the place and before.

                for (j = 0; j < IGC_RSS_RDT_REG_SIZE; j++) {
                        if (mask & (1u << j))
                                reta_conf[idx].reta[shift + j] = reta.bytes[j];