From: Miaoqing Pan <miaoqing@xxxxxxxxxxxxxx> This patch has been added to the stable tree. If you have any objections, please let us know. =============== [ Upstream commit ee0a47186e2fa9aa1c56cadcea470ca0ba8c8692 ] 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 <miaoqing@xxxxxxxxxxxxxx> Reviewed-by: Christoph Böhmwalder <christoph@xxxxxxxxxxxxxx> Signed-off-by: Kalle Valo <kvalo@xxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> --- 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 b4e6304afd40..7ee1a3183a06 100644 --- a/drivers/net/wireless/ath/ath9k/tx99.c +++ b/drivers/net/wireless/ath/ath9k/tx99.c @@ -180,6 +180,9 @@ 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; @@ -187,6 +190,8 @@ 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; -- 2.11.0