From 581f725ccd7e697074aa057fa86bf99b54052c95 Mon Sep 17 00:00:00 2001 From: Vasanthakumar Thiagarajan Date: Tue, 2 Jun 2009 19:28:55 +0530 Subject: [PATCH] ath9k: Fix write callback of 'debug' which configures debug mask Handle error condition on copy_from_user() properly and make sure a NUL terminated char[] is sent to strict_strtoul() for proper conversion. Signed-off-by: Vasanthakumar Thiagarajan Signed-off-by: John W. Linville --- drivers/net/wireless/ath/ath9k/debug.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/debug.c b/drivers/net/wireless/ath/ath9k/debug.c index a42d631..6d20725 100644 --- a/drivers/net/wireless/ath/ath9k/debug.c +++ b/drivers/net/wireless/ath/ath9k/debug.c @@ -49,8 +49,9 @@ static ssize_t read_file_debug(struct file *file, char __user *user_buf, { struct ath_softc *sc = file->private_data; char buf[32]; - unsigned int len = 0; - len += snprintf(buf, sizeof(buf), "0x%08x\n", sc->debug.debug_mask); + unsigned int len; + + len = snprintf(buf, sizeof(buf), "0x%08x\n", sc->debug.debug_mask); return simple_read_from_buffer(user_buf, count, ppos, buf, len); } @@ -60,12 +61,17 @@ static ssize_t write_file_debug(struct file *file, const char __user *user_buf, struct ath_softc *sc = file->private_data; unsigned long mask; char buf[32]; - if (copy_from_user(buf, user_buf, (sizeof(buf) - 1) < count ? - (sizeof(buf) - 1) : count)) - return 0; - buf[sizeof(buf)-1] = 0; - if (strict_strtoul(buf, 0, &mask) == 0) - sc->debug.debug_mask = mask; + ssize_t len; + + len = min(count, sizeof(buf) - 1); + if (copy_from_user(buf, user_buf, len)) + return -EINVAL; + + buf[len] = '\0'; + if (strict_strtoul(buf, 0, &mask)) + return -EINVAL; + + sc->debug.debug_mask = mask; return count; } -- 2.7.4