If ds->ops->get_sset_count() fails then it "count" is a negative error
code such as -EOPNOTSUPP. Because "i" is an unsigned int, the negative
error code is type promoted to a very high value and the loop will
corrupt memory until the system crashes.
Fix this by checking for error codes and changing the type of "i" to
just int.
Fixes: badf3ada60ab ("net: dsa: Provide CPU port statistics to master netdev")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
net/dsa/master.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/net/dsa/master.c b/net/dsa/master.c
index 052a977914a6..63adbc21a735 100644
--- a/net/dsa/master.c
+++ b/net/dsa/master.c
@@ -147,8 +147,7 @@ static void dsa_master_get_strings(struct net_device *dev, uint32_t stringset,
struct dsa_switch *ds = cpu_dp->ds;
int port = cpu_dp->index;
int len = ETH_GSTRING_LEN;
- int mcount = 0, count;
- unsigned int i;
+ int mcount = 0, count, i;
uint8_t pfx[4];
uint8_t *ndata;
@@ -178,6 +177,8 @@ static void dsa_master_get_strings(struct net_device *dev, uint32_t stringset,
*/
ds->ops->get_strings(ds, port, stringset, ndata);
count = ds->ops->get_sset_count(ds, port, stringset);
+ if (count < 0)
+ return;
for (i = 0; i < count; i++) {
memmove(ndata + (i * len + sizeof(pfx)),
ndata + i * len, len - sizeof(pfx));
--
2.30.2
