[U-Boot] [PATCH] lib: fix return codes when CONFIG_SYS_VSNPRINTF is enabled

[U-Boot] [PATCH] lib: fix return codes when CONFIG_SYS_VSNPRINTF is enabled

[Darwin Rambo]

When CONFIG_SYS_VSNPRINTF is enabled, it protects print operations
such as sprintf, snprintf, vsnprintf, etc., from buffer overflows.
But vsnprintf_internal includes the terminating NULL character in
the calculation of number of characters written. This affects sprintf
and snprintf return values. Fix this issue by setting pointer 'str'
back to the location of the '\0'.

Signed-off-by: Darwin Rambo <drambo@broadcom.com>
Reviewed-by: Steve Rae <srae@broadcom.com>
---
 lib/vsprintf.c |    1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 82e5c13..60874da 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -750,6 +750,7 @@ repeat:
 		ADDCH(str, '\0');
 		if (str > end)
 			end[-1] = '\0';
+		--str;
 	}
 #else
 	*str = '\0';
-- 
1.7.9.5

[U-Boot] lib: fix return codes when CONFIG_SYS_VSNPRINTF is enabled

[Tom Rini]

On Thu, Dec 19, 2013 at 03:14:19PM -0800, Darwin Rambo wrote:

> When CONFIG_SYS_VSNPRINTF is enabled, it protects print operations
> such as sprintf, snprintf, vsnprintf, etc., from buffer overflows.
> But vsnprintf_internal includes the terminating NULL character in
> the calculation of number of characters written. This affects sprintf
> and snprintf return values. Fix this issue by setting pointer 'str'
> back to the location of the '\0'.
> 
> Signed-off-by: Darwin Rambo <drambo@broadcom.com>
> Reviewed-by: Steve Rae <srae@broadcom.com>

Applied to u-boot/master, thanks!

-- 
Tom
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