[PATCH 6.1 005/473] speakup: Fix sizeof() vs ARRAY_SIZE() bug

Greg Kroah-Hartman
2024-06-06T14:12:31Z

From: Dan Carpenter <dan.carpenter@linaro.org>

commit 008ab3c53bc4f0b2f20013c8f6c204a3203d0b8b upstream.

The "buf" pointer is an array of u16 values. This code should be
using ARRAY_SIZE() (which is 256) instead of sizeof() (which is 512),
otherwise it can the still got out of bounds.

Fixes: c8d2f34ea96e ("speakup: Avoid crash on very long word")
Cc: stable@vger.kernel.org
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Link: https://lore.kernel.org/r/d16f67d2-fd0a-4d45-adac-75ddd11001aa@moroto.mountain
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/accessibility/speakup/main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/accessibility/speakup/main.c
+++ b/drivers/accessibility/speakup/main.c
@@ -573,7 +573,7 @@ static u_long get_word(struct vc_data *v
}
attr_ch = get_char(vc, (u_short *)tmp_pos, &spk_attr);
buf[cnt++] = attr_ch;
- while (tmpx < vc->vc_cols - 1 && cnt < sizeof(buf) - 1) {
+ while (tmpx < vc->vc_cols - 1 && cnt < ARRAY_SIZE(buf) - 1) {
tmp_pos += 2;
tmpx++;
ch = get_char(vc, (u_short *)tmp_pos, &temp);