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libertas: fix write past end of array in mesh_id_get() 

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@gmail.com>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Dan Carpenter 2011-03-10 18:23:26 +03:00 committed by John W. Linville
parent 23952ec928
commit d89dba7a27
1 changed files with 4 additions and 7 deletions
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11
drivers/net/wireless/libertas/mesh.c
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@ -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;
}
/**