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| author | Dan Carpenter <error27@gmail.com> | 2011-03-10 18:23:26 +0300 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2011-03-11 14:15:36 -0500 |
| commit | d89dba7a275f40757d27ba16c8bc6aa424656bbe (patch) | |
| tree | c42b16fc568b9ffdb0458b59c6112f9eb9f24792 | |
| parent | 23952ec92850bcdc91b8167fa95ec05dd59a80ea (diff) | |
| download | lwn-d89dba7a275f40757d27ba16c8bc6aa424656bbe.tar.gz lwn-d89dba7a275f40757d27ba16c8bc6aa424656bbe.zip | |
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>
| -rw-r--r-- | drivers/net/wireless/libertas/mesh.c | 11 |
1 files changed, 4 insertions, 7 deletions
diff --git a/drivers/net/wireless/libertas/mesh.c b/drivers/net/wireless/libertas/mesh.c index acf3bf63ee33..9d097b9c8005 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; } /** |