From ee0a47186e2fa9aa1c56cadcea470ca0ba8c8692 Mon Sep 17 00:00:00 2001 From: Miaoqing Pan Date: Wed, 27 Sep 2017 09:13:34 +0800 Subject: [PATCH] ath9k: fix tx99 potential info leak MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When the user sets count to zero the string buffer would remain completely uninitialized which causes the kernel to parse its own stack data, potentially leading to an info leak. In addition to that, the string might be not terminated properly when the user data does not contain a 0-terminator. Signed-off-by: Miaoqing Pan Reviewed-by: Christoph Böhmwalder Signed-off-by: Kalle Valo --- drivers/net/wireless/ath/ath9k/tx99.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/net/wireless/ath/ath9k/tx99.c b/drivers/net/wireless/ath/ath9k/tx99.c index 49ed1afb913c..fe3a8263b224 100644 --- a/drivers/net/wireless/ath/ath9k/tx99.c +++ b/drivers/net/wireless/ath/ath9k/tx99.c @@ -179,6 +179,9 @@ static ssize_t write_file_tx99(struct file *file, const char __user *user_buf, ssize_t len; int r; + if (count < 1) + return -EINVAL; + if (sc->cur_chan->nvifs > 1) return -EOPNOTSUPP; @@ -186,6 +189,8 @@ static ssize_t write_file_tx99(struct file *file, const char __user *user_buf, if (copy_from_user(buf, user_buf, len)) return -EFAULT; + buf[len] = '\0'; + if (strtobool(buf, &start)) return -EINVAL;