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Date: Mon, 15 Apr 2024 14:02:23 +0300
From: Dan Carpenter <dan.carpenter@linaro.org>
To: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: William Hubbs <w.d.hubbs@gmail.com>,
	Chris Brannon <chris@the-brannons.com>,
	Kirk Reiser <kirk@reisers.ca>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Randy Dunlap <rdunlap@infradead.org>, speakup@linux-speakup.org,
	linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org
Subject: [PATCH] speakup: Fix sizeof() vs ARRAY_SIZE() bug
Message-ID: <d16f67d2-fd0a-4d45-adac-75ddd11001aa@moroto.mountain>
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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>
---
 drivers/accessibility/speakup/main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/accessibility/speakup/main.c b/drivers/accessibility/speakup/main.c
index 736c2eb8c0f3..f677ad2177c2 100644
--- a/drivers/accessibility/speakup/main.c
+++ b/drivers/accessibility/speakup/main.c
@@ -574,7 +574,7 @@ static u_long get_word(struct vc_data *vc)
 	}
 	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);
-- 
2.43.0