mwifiex: debugfs: Fix (sometimes) off-by-1 SSID print

BugLink: http://bugs.launchpad.net/bugs/1691418
commit 6183468a23fc6b6903f8597982017ad2c7fdefcf upstream.

Similar to commit fcd2042e8d36 ("mwifiex: printk() overflow with 32-byte
SSIDs"), we failed to account for the existence of 32-char SSIDs in our
debugfs code. Unlike in that case though, we zeroed out the containing
struct first, and I'm pretty sure we're guaranteed to have some padding
after the 'ssid.ssid' and 'ssid.ssid_len' fields (the struct is 33 bytes
long).

So, this is the difference between:

  # cat /sys/kernel/debug/mwifiex/mlan0/info
  ...
  essid="0123456789abcdef0123456789abcdef "
  ...

and the correct output:

  # cat /sys/kernel/debug/mwifiex/mlan0/info
  ...
  essid="0123456789abcdef0123456789abcdef"
  ...

Fixes: 5e6e3a92b9a4 ("wireless: mwifiex: initial commit for Marvell mwifiex driver")
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

diff --git a/drivers/net/wireless/mwifiex/debugfs.c b/drivers/net/wireless/mwifiex/debugfs.c
index 9824d8dd2b4447f11304557a44f3c7ea2d629d76..45d97b64ef84b5871dbecd47f423ad1ecd9a98e9 100644 (file)
--- a/drivers/net/wireless/mwifiex/debugfs.c
+++ b/drivers/net/wireless/mwifiex/debugfs.c
@@ -115,7 +115,8 @@ mwifiex_info_read(struct file *file, char __user *ubuf,
        if (GET_BSS_ROLE(priv) == MWIFIEX_BSS_ROLE_STA) {
                p += sprintf(p, "multicast_count=\"%d\"\n",
                             netdev_mc_count(netdev));
-               p += sprintf(p, "essid=\"%s\"\n", info.ssid.ssid);
+               p += sprintf(p, "essid=\"%.*s\"\n", info.ssid.ssid_len,
+                            info.ssid.ssid);
                p += sprintf(p, "bssid=\"%pM\"\n", info.bssid);
                p += sprintf(p, "channel=\"%d\"\n", (int) info.bss_chan);
                p += sprintf(p, "country_code = \"%s\"\n", info.country_code);