Re: [libvirt] [PATCH] Fix Invalid write in virCryptoHashString()
On 03/12/2014 03:44 PM, Nehal J Wani wrote:
While running vircryptotest, it was found that valgrind pointed out
the
following error:
==27453== Invalid write of size 1
==27453== at 0x4C7D7C9: virCryptoHashString (vircrypto.c:76)
---
The errors go away, if I either do:
Line 76: (*output)[hashstrlen - 1] = '\0';
This is correct, since we initialized hashstrlen to be strlen()+1 in
the first place.
or
Line 61: if (VIR_ALLOC_N(*output, hashstrlen + 1) < 0)
But the second one seems less harmful, as anyway we are going to free
that memory.
Overallocating by 2 is pointless. But so is writing a trailing NUL, as
the string is already zero-initialized by VIR_ALLOC_N.
So the CORRECT fix, which I am pushing shortly, is to just delete the
redundant line:
(*output)[hashstrlen] = '\0';
--
Eric Blake eblake redhat com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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