Commit 525fda92 authored Jan 09, 2017 by Brian Norris Committed by Greg Kroah-Hartman May 14, 2017

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



commit 6183468a23fc6b6903f8597982017ad2c7fdefcf upstream.

Similar to commit fcd2042e ("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: 5e6e3a92 ("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>

parent 1d61da61

drivers/net/wireless/marvell/mwifiex/debugfs.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -114,7 +114,8 @@ 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);