Adam Goryachev <mailinglists@xxxxxxxxxxxxxxxxxxxxxx> writes: > On 16/09/16 04:10, Thomas Fjellstrom wrote: >> On Thursday, September 15, 2016 12:15:30 PM MDT Jes Sorensen wrote: >>> I was about to apply this, but this is actually wrong. You need to use >>> the size of the destination, not of the source as the limit. >>> >>> Sorry for the hassle. >> I'm not aware of the full details, but either they are the same size, or they >> aren't, and you need to use the minimum size of both to avoid any kind of >> overflow (source or dest, read and write). I presume the destination is >> smaller? > I'm not a programmer, but I think the size of the source is > irrelevant. If the source is 10 bytes, you can safely copy that to a > destination of 30 bytes. The only problem is if the source content is > bigger than the destination. Hence, you should copy only based on the > destination size. > > I'm not sure, but it may be a good idea to confirm that all of the > source content has been copied, or else there may be unexpected > results when operating on a truncated value. I'm sure someone else > who is an actual programmer can jump in and advise... Technically you are correct. However if we start adding such checks, there's a full time job running through the code fixing up cases like these. This for cases where we know it won't go wrong. It would also be a large amount of patch churn for no gain. Cheers, Jes -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
