[libvirt] [PATCH 2/2] esx_vi: fix possible segfault

[Peter Krempa]

On Wed, Jan 21, 2015 at 18:09:28 +0100, Pavel Hrdina wrote:
> Clang found possible dereference of NULL pointer which is right.
> Function 'esxVI_LookupTaskInfoByTask' should find a task info. The issue
> is that we could return 0 and leave 'taksInfo' pointer NULL because if
> there is no match we simply end the search loop end set 'result' to 0.
> Every caller count on the fact that if the return value is 0 than it's
> safe to dereference 'taskInfo'. We should return 0 only in case we found
> something and the '*taskInfo' is not NULL.
> 
> Signed-off-by: Pavel Hrdina <phrdina at redhat.com>
> ---
>  src/esx/esx_vi.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/src/esx/esx_vi.c b/src/esx/esx_vi.c
> index a87f2c0..752d32a 100644
> --- a/src/esx/esx_vi.c
> +++ b/src/esx/esx_vi.c
> @@ -3298,7 +3298,8 @@ esxVI_LookupTaskInfoByTask(esxVI_Context *ctx,
>          }
>      }
>  
> -    result = 0;
> +    if (*taskInfo)
> +        result = 0;

I think a more obvious fix would be to move setting of result to zero
into the condition that breaks the loop. In that case, result gets set
to 0 only if the entry was found.

>  
>   cleanup:
>      esxVI_String_Free(&propertyNameList);

ACK with or without that change. I think that this wasn't discovered due
to the fact that the correct entry is always in the list and is always
first as we haven't seen reports for spamming the warning.

Peter

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