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

[ Upstream commit 6183468a23fc6b6903f8597982017ad2c7fdefcf ]

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: Sasha Levin <alexander.levin@verizon.com>

diff --git a/drivers/net/wireless/mwifiex/debugfs.c b/drivers/net/wireless/mwifiex/debugfs.c
index 24e48bddf186ae2d2335ae5069b152cef35cfca4..a97da679e7a8de67a927184d13817d3ae965e292 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);