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From: Len Baker <len.baker@gmx.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Len Baker <len.baker@gmx.com>,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Phil Reid <preid@electromag.com.au>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org,
	linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: [PATCH v2 1/3] staging/fbtft: Remove all strcpy() uses
Date: Sat, 24 Jul 2021 17:14:09 +0200	[thread overview]
Message-ID: <20210724151411.9531-2-len.baker@gmx.com> (raw)
In-Reply-To: <20210724151411.9531-1-len.baker@gmx.com>

strcpy() performs no bounds checking on the destination buffer. This
could result in linear overflows beyond the end of the buffer, leading
to all kinds of misbehaviors. The safe replacement is strscpy() but in
this case it is simpler to use the "%*ph" format specifier.

Signed-off-by: Len Baker <len.baker@gmx.com>
---
 drivers/staging/fbtft/fbtft-core.c | 17 ++++++-----------
 1 file changed, 6 insertions(+), 11 deletions(-)

diff --git a/drivers/staging/fbtft/fbtft-core.c b/drivers/staging/fbtft/fbtft-core.c
index 3723269890d5..be20da3c4a5c 100644
--- a/drivers/staging/fbtft/fbtft-core.c
+++ b/drivers/staging/fbtft/fbtft-core.c
@@ -992,8 +992,6 @@ static int fbtft_init_display_from_property(struct fbtft_par *par)
 int fbtft_init_display(struct fbtft_par *par)
 {
 	int buf[64];
-	char msg[128];
-	char str[16];
 	int i = 0;
 	int j;

@@ -1036,17 +1034,14 @@ int fbtft_init_display(struct fbtft_par *par)
 		switch (par->init_sequence[i]) {
 		case -1:
 			i++;
+
 			/* make debug message */
-			strcpy(msg, "");
-			j = i + 1;
-			while (par->init_sequence[j] >= 0) {
-				sprintf(str, "0x%02X ", par->init_sequence[j]);
-				strcat(msg, str);
-				j++;
-			}
+			for (j = i + 1; par->init_sequence[j] >= 0; j++);
+
 			fbtft_par_dbg(DEBUG_INIT_DISPLAY, par,
-				      "init: write(0x%02X) %s\n",
-				      par->init_sequence[i], msg);
+				      "init: write(0x%02X) %*ph\n",
+				      par->init_sequence[i], j - i - 1,
+				      &par->init_sequence[i + 1]);

 			/* Write */
 			j = 0;
--
2.25.1


  reply	other threads:[~2021-07-24 16:04 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-24 15:14 [PATCH v2 0/3] " Len Baker
2021-07-24 15:14 ` Len Baker [this message]
2021-07-24 20:21   ` [PATCH v2 1/3] staging/fbtft: " Andy Shevchenko
2021-07-25 13:58     ` Len Baker
2021-07-25 18:51       ` Andy Shevchenko
2021-07-31 13:43         ` Len Baker
2021-07-24 15:14 ` [PATCH v2 2/3] staging/fbtft: Remove unnecessary variable initialization Len Baker
2021-07-24 15:14 ` [PATCH v2 3/3] staging/fbtft: Fix braces coding style Len Baker
2021-07-24 18:01   ` Geert Uytterhoeven
2021-07-25 14:02     ` Len Baker

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