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From: "Tobin C. Harding" <me@tobin.cc>
To: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>,
	noralf@tronnes.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org,
	"Tobin C. Harding" <me@tobin.cc>
Subject: [PATCH v2 3/3] staging: fbtft: Add check on strlcpy() return value
Date: Wed, 15 Feb 2017 14:27:25 +1100	[thread overview]
Message-ID: <1487129245-24970-4-git-send-email-me@tobin.cc> (raw)
In-Reply-To: <1487129245-24970-1-git-send-email-me@tobin.cc>

Return value of strlcpy() is not checked. Name string is silently
truncated if longer that SPI_NAME_SIZE, whilst not detrimental to
the program logic it would be nice to notify the user. Module is
currently quite verbose, adding extra pr_warn() calls will not overly
impact this verbosity.

Check return value from call to strlcpy(). If source string is
truncated call pr_warn() to notify user.

Signed-off-by: Tobin C. Harding <me@tobin.cc>
---
 drivers/staging/fbtft/fbtft_device.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/fbtft/fbtft_device.c b/drivers/staging/fbtft/fbtft_device.c
index 5fbdd37..78baf46 100644
--- a/drivers/staging/fbtft/fbtft_device.c
+++ b/drivers/staging/fbtft/fbtft_device.c
@@ -1483,7 +1483,13 @@ static int __init fbtft_device_init(void)
 			displays[i].pdev->name = name;
 			displays[i].spi = NULL;
 		} else {
-			strlcpy(displays[i].spi->modalias, name, SPI_NAME_SIZE);
+			size_t len;
+
+			len = strlcpy(displays[i].spi->modalias, name,
+				SPI_NAME_SIZE);
+			if (len >= SPI_NAME_SIZE)
+				pr_warn("modalias (name) truncated to: %s\n",
+					displays[i].spi->modalias);
 			displays[i].pdev = NULL;
 		}
 	}
-- 
2.7.4

      parent reply	other threads:[~2017-02-15  3:28 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-15  3:27 [PATCH v2 0/3] staging: fbtft: Fix buffer overflow vulnerability Tobin C. Harding
2017-02-15  3:27 ` [PATCH v2 1/3] " Tobin C. Harding
2017-02-15  3:27 ` [PATCH v2 2/3] staging: fbtft: Replace magic number with constant Tobin C. Harding
2017-02-15  3:36   ` Joe Perches
2017-02-15  3:27 ` Tobin C. Harding [this message]

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