There is a general misunderstanding amongst engineers that {v}snprintf()
returns the length of the data *actually* encoded into the destination
array. However, as per the C99 standard {v}snprintf() really returns
the length of the data that *would have been* written if there were
enough space for it. This misunderstanding has led to buffer-overruns
in the past. It's generally considered safer to use the {v}scnprintf()
variants in their place (or even sprintf() in simple cases). So let's
do that.
Link: https://lwn.net/Articles/69419/
Link: https://github.com/KSPP/linux/issues/105
Signed-off-by: Lee Jones <lee@xxxxxxxxxx>
---
drivers/usb/mon/mon_stat.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/mon/mon_stat.c b/drivers/usb/mon/mon_stat.c
index 98ab0cc473d67..3c23805ab1a44 100644
--- a/drivers/usb/mon/mon_stat.c
+++ b/drivers/usb/mon/mon_stat.c
@@ -35,9 +35,9 @@ static int mon_stat_open(struct inode *inode, struct file *file)
mbus = inode->i_private;
- sp->slen = snprintf(sp->str, STAT_BUF_SIZE,
- "nreaders %d events %u text_lost %u\n",
- mbus->nreaders, mbus->cnt_events, mbus->cnt_text_lost);
+ sp->slen = scnprintf(sp->str, STAT_BUF_SIZE,
+ "nreaders %d events %u text_lost %u\n",
+ mbus->nreaders, mbus->cnt_events, mbus->cnt_text_lost);
file->private_data = sp;
return 0;
--
2.43.0.472.g3155946c3a-goog
