Messages in this thread | | | Date | Wed, 27 Apr 2011 08:37:42 +0200 | From | Martin Schwidefsky <> | Subject | Re: [GIT PULL] s390 patches for 2.6.39-rc4 |
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On Tue, 26 Apr 2011 11:38:22 -0700 Linus Torvalds <torvalds@linux-foundation.org> wrote:
> I'll pull this, but: > > On Tue, Apr 26, 2011 at 2:03 AM, Martin Schwidefsky > <schwidefsky@de.ibm.com> wrote: > > > > Jan Glauber (3): > > [S390] prng: prevent access beyond end of stack > > I don't think that's _still_ correct. > > Just looking at the diff, it looks broken: > > > /* Add the entropy */ > > while (nbytes >= 8) { > > - *((__u64 *)parm_block) ^= *((__u64 *)buf+i*8); > > + *((__u64 *)parm_block) ^= *((__u64 *)buf+i); > > prng_add_entropy(); > > i += 8; > > nbytes -= 8; > > The "i += 8" implies that "i" is a byte offset. > > But "(__u64 *)buf+i" will parse as "((__u64 *)buf) + i" and thus still > do another multiply-by-eight. > > So the diff fixes one "off by a factor of 8", but not another, if I > read it right. > > So the parenthesis should be moved around to something like "*(__u64 > *) (buf+i)", I think.
Urgs, pointer arithmetic for dummies.. it is indeed still wrong. We'll fix.
-- blue skies, Martin.
"Reality continues to ruin my life." - Calvin.
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