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 <vasanth@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
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 @@
{
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 @@
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;
}