On 22 April 2015 at 16:45, Stefan Roese <s...@denx.de> wrote: > On 22.04.2015 13:11, Jagan Teki wrote: >>> >>> On 12.01.2015 22:10, Wolfgang Denk wrote: >>>>>> >>>>>> >>>>>> Should we add a memset(buf, 0, sizeof(buf)) before the memcpy() to >>>>>> prevent information from earlier activities to leak? >>>>> >>>>> >>>>> >>>>> "buf" points to the new data to be written into the flash. We're >>>>> overwriting the first "len" bytes of "cmp_buf" with this data. >>>> >>>> >>>> >>>> Oh, sorry for the mixup. Then cmp_buf should be cleared (or at elast >>>> the remaining, unused part). >>> >>> >>> >>> No. cmp_buf contains the original data from the flash. And only the >>> beginning of this buffer is overwritten with the new data from "buf". So, >>> the result of the memcpy() is that "cmp_buf" contains the data that >>> should >>> be written into the flash. Its a combination of the "original data" and >>> the >>> "new data". >>> >>>>> I don't see why we should erase anything there. Perhaps I'm missing >>>>> something though. >>>> >>>> >>>> >>>> You are leaking data. This could contain "interesting" information; >>>> see the OpenSSL “Heartbleed” vulnerability for a (nasty) example what >>>> information leakage can do. >>> >>> >>> >>> There is nothing leaking here. When anything would be zeroed out, the >>> resulting buffer would not be the one that should be used. >> >> >> I think this thread link got stopped any further update on this. > > > I would have thought that this patch had been applied some time ago. If not, > then please do.
Applied to u-boot-spi/master thanks! -- Jagan. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot
