Re: [PATCH] drivers/input: Remove all strcpy() uses in favor of strscpy()
From: "Russell King (Oracle)" <linux@armlinux.org.uk>
Date: 2021-08-01 15:00:15
Also in:
linux-hardening, lkml
On Sun, Aug 01, 2021 at 04:43:16PM +0200, Len Baker wrote:
quoted hunk ↗ jump to hunk
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(). Signed-off-by: Len Baker <redacted> --- This is a task of the KSPP [1] [1] https://github.com/KSPP/linux/issues/88 drivers/input/keyboard/locomokbd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/input/keyboard/locomokbd.c b/drivers/input/keyboard/locomokbd.c index dae053596572..dbb3dc48df12 100644 --- a/drivers/input/keyboard/locomokbd.c +++ b/drivers/input/keyboard/locomokbd.c@@ -254,7 +254,7 @@ static int locomokbd_probe(struct locomo_dev *dev) locomokbd->suspend_jiffies = jiffies; locomokbd->input = input_dev; - strcpy(locomokbd->phys, "locomokbd/input0"); + strscpy(locomokbd->phys, "locomokbd/input0", sizeof(locomokbd->phys));
So if the string doesn't fit, it's fine to silently truncate it? Rather than converting every single strcpy() in the kernel to strscpy(), maybe there should be some consideration given to how the issue of a strcpy() that overflows the buffer should be handled. E.g. in the case of a known string such as the above, if it's longer than the destination, should we find a way to make the compiler issue a warning at compile time? -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!