[PATCH] tdb: Fix a possible null pointer dereference.

[Andreas Schneider]

On Thursday 22 November 2012 12:09:45 Andreas Schneider wrote:
> Signed-off-by: Andreas Schneider <asn at samba.org>
> ---
>  lib/tdb/common/error.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/lib/tdb/common/error.c b/lib/tdb/common/error.c
> index 2aaaa81..ddb93af 100644
> --- a/lib/tdb/common/error.c
> +++ b/lib/tdb/common/error.c
> @@ -29,6 +29,10 @@
> 
>  _PUBLIC_ enum TDB_ERROR tdb_error(struct tdb_context *tdb)
>  {
> +	if (tdb == NULL) {
> +		return TDB_ERR_EINVAL;
> +	}
> +
>  	return tdb->ecode;
>  }

This only happens in a rare case when reopening a tdb fails, eventually 
freeing the mentioned pointer via tdb_close. The freed pointer is then 
dereferenced again during error reporting.

(Found by RHN Coverity Scan)

-- 
Andreas Schneider                   GPG-ID: F33E3FC6
Samba Team                             asn at samba.org
www.samba.org