This is a cross-post from glibc bugreport:
http://sourceware.org/bugzilla/show_bug.cgi?id=14090
In short, the code below handles blocks larger than 8 GB incorrectly because
they require ctx->total[1] incremented more than by 1:
------------------------------------------------------------------------------
/* First increment the byte count. RFC 1321 specifies the possible
length of the file up to 2^64 bits. Here we only compute the
number of bytes. Do a double word increment. */
ctx->total[0] += len;
if (ctx->total[0] < len)
++ctx->total[1];
------------------------------------------------------------------------------
Note that md5sum is not affected by this, as it calls
md5_process_block() with small and fixed block size.
Testcase for the bug:
http://sourceware.org/bugzilla/attachment.cgi?id=6411
