From: Miaoqing Pan <[email protected]> [ 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 <[email protected]> Reviewed-by: Christoph Böhmwalder <[email protected]> Signed-off-by: Kalle Valo <[email protected]> Signed-off-by: Sasha Levin <[email protected]> --- 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
