[PATCH 04/15] accessibility: speakup: Fix incorrect string length computation in report_char_chartab_status()

From: Samuel Thibault

Date: Sun May 31 2026 - 19:14:32 EST


From: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>

snprintf() returns the "number of characters which *would* be generated for
the given input", not the size *really* generated.

In order to avoid too large values for 'len' (and potential negative
values for "sizeof(buf) - (len - 1)") use scnprintf() instead of
snprintf().

Fixes: c6e3fd22cd53 ("Staging: add speakup to the staging directory")
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
Signed-off-by: Samuel Thibault <samuel.thibault@xxxxxxxxxxxx>
---
drivers/accessibility/speakup/kobjects.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/accessibility/speakup/kobjects.c b/drivers/accessibility/speakup/kobjects.c
index 0dfdb6608e02..943ef71b1329 100644
--- a/drivers/accessibility/speakup/kobjects.c
+++ b/drivers/accessibility/speakup/kobjects.c
@@ -92,9 +92,9 @@ static void report_char_chartab_status(int reset, int received, int used,
if (reset) {
pr_info("%s reset to defaults\n", object_type[do_characters]);
} else if (received) {
- len = snprintf(buf, sizeof(buf),
- " updated %d of %d %s\n",
- used, received, object_type[do_characters]);
+ len = scnprintf(buf, sizeof(buf),
+ " updated %d of %d %s\n",
+ used, received, object_type[do_characters]);
if (rejected)
snprintf(buf + (len - 1), sizeof(buf) - (len - 1),
" with %d reject%s\n",
--
2.47.3