From d89dba7a275f40757d27ba16c8bc6aa424656bbe Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Thu, 10 Mar 2011 18:23:26 +0300 Subject: [PATCH] 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 Acked-by: Dan Williams Signed-off-by: John W. Linville --- drivers/net/wireless/libertas/mesh.c | 11 ++++------- 1 file 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; } /** -- 2.34.1