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Re: [libvirt] [PATCH v2] buf: Fix possible infinite loop in EscapeString, VSnprintf

On 09/01/2010 03:41 PM, Cole Robinson wrote:
The current code will go into an infinite loop if the printf generated
string is>= 1000, AND exactly 1 character smaller than the amount of free
space in the buffer. When this happens, we are dropped into the loop body,
but nothing will actually change, because count == (buf->size - buf->use - 1),
and virBufferGrow returns unchanged if count<  (buf->size - buf->use)

Fix this by removing the '- 1' bit from 'size'. The *nprintf functions handle
the NULL byte for us anyways, so we shouldn't need to manually accomodate


for it.

Here's a bug where we are actually hitting this issue:

v2: Eric's improvements: while ->  if (), remove extra va_list variable,
     make sure we report buffer error if snprintf fails

ACK, with one spelling nit in the commit message.

Eric Blake   eblake redhat com    +1-801-349-2682
Libvirt virtualization library http://libvirt.org

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