[patch] libertas: fix write past end of array in mesh_id_get()
Dan Carpenter
error27 at gmail.com
Thu Mar 10 10:23:26 EST 2011
defs.meshie.val.mesh_id is 32 chars long. It's not supposed to be NUL
terminated. This code puts a terminator on the end to make it easier to
print to sysfs. The problem is that if the mesh_id fills the entire
buffer the original code puts the terminator one spot past the end.
The way the original code was written, there was a check to make sure
that maxlen was less than PAGE_SIZE. Since we know that maxlen is at
most 34 chars, I just removed the check.
Signed-off-by: Dan Carpenter <error27 at gmail.com>
diff --git a/drivers/net/wireless/libertas/mesh.c b/drivers/net/wireless/libertas/mesh.c
index acf3bf6..9d097b9 100644
--- a/drivers/net/wireless/libertas/mesh.c
+++ b/drivers/net/wireless/libertas/mesh.c
@@ -918,7 +918,6 @@ static ssize_t mesh_id_get(struct device *dev, struct device_attribute *attr,
char *buf)
{
struct mrvl_mesh_defaults defs;
- int maxlen;
int ret;
ret = mesh_get_default_parameters(dev, &defs);
@@ -931,13 +930,11 @@ static ssize_t mesh_id_get(struct device *dev, struct device_attribute *attr,
defs.meshie.val.mesh_id_len = IEEE80211_MAX_SSID_LEN;
}
- /* SSID not null terminated: reserve room for \0 + \n */
- maxlen = defs.meshie.val.mesh_id_len + 2;
- maxlen = (PAGE_SIZE > maxlen) ? maxlen : PAGE_SIZE;
+ memcpy(buf, defs.meshie.val.mesh_id, defs.meshie.val.mesh_id_len);
+ buf[defs.meshie.val.mesh_id_len] = '\n';
+ buf[defs.meshie.val.mesh_id_len + 1] = '\0';
- defs.meshie.val.mesh_id[defs.meshie.val.mesh_id_len] = '\0';
-
- return snprintf(buf, maxlen, "%s\n", defs.meshie.val.mesh_id);
+ return defs.meshie.val.mesh_id_len + 1;
}
/**
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