From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wei Liu Subject: Re: [PATCH] tools/xl: Fix trim() following c/s e316316 "xl: Rewrite trim()" Date: Thu, 16 Jul 2015 21:47:49 +0100 Message-ID: <20150716204749.GD29094@zion.uk.xensource.com> References: <1437074311-25446-1-git-send-email-andrew.cooper3@citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1437074311-25446-1-git-send-email-andrew.cooper3@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Andrew Cooper Cc: Wei Liu , Ian Jackson , Ian Campbell , Xen-devel List-Id: xen-devel@lists.xenproject.org On Thu, Jul 16, 2015 at 08:18:31PM +0100, Andrew Cooper wrote: > c/s e316316 "xl: Rewrite trim()" uses the wrong indirection of > 'output', causing memory corruption for all callers. > > Introduce a new local variable, making the code more obviously > correct. > > Signed-off-by: Andrew Cooper > CC: Ian Campbell > CC: Ian Jackson > CC: Wei Liu Acked-by: Wei Liu One nit below. > --- > tools/libxl/xl_cmdimpl.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c > index 37d4af6..0cc9f8b 100644 > --- a/tools/libxl/xl_cmdimpl.c > +++ b/tools/libxl/xl_cmdimpl.c > @@ -663,10 +663,12 @@ static void trim(char_predicate_t predicate, const char *input, char **output) > ; > > size_t len_nonnull = after - first; > + char *result = xmalloc(len_nonnull + 1); > Can you move the declaration of result to the beginning of this function? > - *output = xmalloc(len_nonnull + 1); > - memcpy(output, first, len_nonnull); > - output[len_nonnull] = 0; > + memcpy(result, first, len_nonnull); > + result[len_nonnull] = 0; > + > + *output = result; > } > > static int split_string_into_pair(const char *str, > -- > 1.7.10.4