[PATCH v2] serial: samsung: fix buffer size for clk_name

From: "Alexey V. Vissarionov" <gremlin@altlinux.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Alexey V. Vissarionov" <gremlin@altlinux.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
	Alim Akhtar <alim.akhtar@samsung.com>,
	Jiri Slaby <jirislaby@kernel.org>,
	Thomas Abraham <thomas.abraham@linaro.org>,
	Kukjin Kim <kgene.kim@samsung.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-samsung-soc@vger.kernel.org, linux-serial@vger.kernel.org,
	lvc-project@linuxtesting.org
Subject: [PATCH v2] serial: samsung: fix buffer size for clk_name
Date: Wed, 1 Feb 2023 05:44:57 +0300	[thread overview]
Message-ID: <20230201024457.GD446@altlinux.org> (raw)
In-Reply-To: <Y8lZNi9pYVFkYvh9@kroah.com>

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serial: samsung: fix buffer size for clk_name

Although very unlikely, the 'clk_num' value may be as big as
2**32 - 1 (uint32_max), so the buffer should have enough
space for storing "clk_uart_baud4294967295\0".
Also, the numbers in clk_name are expected to be unsigned.

Found by ALT Linux Team (altlinux.org) and Linux Verification
Center (linuxtesting.org) using SVACE.

Signed-off-by: Alexey V. Vissarionov <gremlin@altlinux.org>
Fixes: 5f5a7a5578c5 ("serial: samsung: switch to clkdev based clock lookup")

---

On 2023-01-19 15:52:38 +0100, Greg Kroah-Hartman wrote:

 >> Fixes: 5f5a7a5578c58852 ("serial: samsung: switch to clkdev
 >> based clock lookup")
 > Please fix your scripts to use the proper number of SHA1 digits
 > in a Fixes: line as the documentation asks for.

Done. Also added the comment to the source regarding the buffer size.

diff --git a/drivers/tty/serial/samsung_tty.c b/drivers/tty/serial/samsung_tty.c
index 0fce856434dafd80..2c701dc7c6a37191 100644
--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -1407,7 +1407,7 @@ static void s3c24xx_serial_pm(struct uart_port *port, unsigned int level,
  *
  */
 
-#define MAX_CLK_NAME_LENGTH 15
+#define MAX_CLK_NAME_LENGTH 24		/* "clk_uart_baud4294967295\0" */
 
 static inline int s3c24xx_serial_getsource(struct uart_port *port)
 {
@@ -1457,7 +1457,7 @@ static unsigned int s3c24xx_serial_getclk(struct s3c24xx_uart_port *ourport,
 			!(ourport->cfg->clk_sel & (1 << cnt)))
 			continue;
 
-		sprintf(clkname, "clk_uart_baud%d", cnt);
+		sprintf(clkname, "clk_uart_baud%u", cnt);
 		clk = clk_get(ourport->port.dev, clkname);
 		if (IS_ERR(clk))
 			continue;
@@ -1957,7 +1957,7 @@ static int s3c24xx_serial_enable_baudclk(struct s3c24xx_uart_port *ourport)
 		if (!(clk_sel & (1 << clk_num)))
 			continue;
 
-		sprintf(clk_name, "clk_uart_baud%d", clk_num);
+		sprintf(clk_name, "clk_uart_baud%u", clk_num);
 		clk = clk_get(dev, clk_name);
 		if (IS_ERR(clk))
 			continue;
@@ -2522,7 +2522,7 @@ s3c24xx_serial_get_options(struct uart_port *port, int *baud,
 		/* now calculate the baud rate */
 
 		clk_sel = s3c24xx_serial_getsource(port);
-		sprintf(clk_name, "clk_uart_baud%d", clk_sel);
+		sprintf(clk_name, "clk_uart_baud%u", clk_sel);
 
 		clk = clk_get(port->dev, clk_name);
 		if (!IS_ERR(clk))


-- 
Alexey V. Vissarionov
gremlin ПРИ altlinux ТЧК org; +vii-cmiii-ccxxix-lxxix-xlii
GPG: 0D92F19E1C0DC36E27F61A29CD17E2B43D879005 @ hkp://keys.gnupg.net

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