Reviewed-by: Liming Gao <[email protected]> Besides, if you expect me to commit this patch, please send the patch as attachment to me, I would like to help do it.
Thanks Liming -----Original Message----- From: Yao, Jiewen Sent: Monday, July 13, 2015 12:11 PM To: Leif Lindholm; [email protected] Cc: Kinney, Michael D; Gao, Liming; [email protected] Subject: RE: [Linaro-uefi] [PATCH] MdePkg: ensure SafeString length functions don't access beyond MaxSize Thank to catch this. Reviewed by: Yao, Jiewen <[email protected]> -----Original Message----- From: Linaro-uefi [mailto:[email protected]] On Behalf Of Leif Lindholm Sent: Friday, July 10, 2015 9:21 PM To: [email protected] Cc: Kinney, Michael D; Gao, Liming; [email protected] Subject: [Linaro-uefi] [PATCH] MdePkg: ensure SafeString length functions don't access beyond MaxSize The StrnLenS and AsciiStrnLenS functions, when presented with a string with no terminating NULL in the first MaxSize characters will check the character at String[MaxSize] before checking if Length < MaxSize. (They return the correct value, but have accessed beyond the stated limit in the process.) Flip the order of the tests to prevent this behaviour. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Leif Lindholm <[email protected]> --- MdePkg/Library/BaseLib/SafeString.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/MdePkg/Library/BaseLib/SafeString.c b/MdePkg/Library/BaseLib/SafeString.c index 7c1b075..b0e1ce7 100644 --- a/MdePkg/Library/BaseLib/SafeString.c +++ b/MdePkg/Library/BaseLib/SafeString.c @@ -141,7 +141,7 @@ StrnLenS ( // String then StrnLenS returns MaxSize. At most the first MaxSize characters of String shall // be accessed by StrnLenS. // - for (Length = 0; (*String != 0) && (Length < MaxSize); String++, Length++) { + for (Length = 0; (Length < MaxSize) && (*String != 0); String++, + Length++) { ; } return Length; @@ -551,7 +551,7 @@ AsciiStrnLenS ( // String then AsciiStrnLenS returns MaxSize. At most the first MaxSize characters of String shall // be accessed by AsciiStrnLenS. // - for (Length = 0; (*String != 0) && (Length < MaxSize); String++, Length++) { + for (Length = 0; (Length < MaxSize) && (*String != 0); String++, + Length++) { ; } return Length; -- 2.1.4 _______________________________________________ Linaro-uefi mailing list [email protected] https://lists.linaro.org/mailman/listinfo/linaro-uefi ------------------------------------------------------------------------------ Don't Limit Your Business. Reach for the Cloud. GigeNET's Cloud Solutions provide you with the tools and support that you need to offload your IT needs and focus on growing your business. Configured For All Businesses. Start Your Cloud Today. https://www.gigenetcloud.com/ _______________________________________________ edk2-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/edk2-devel
