From: Konstantin Kostiuk <konstantin@daynix.com>
To: "Daniel P. Berrangé" <berrange@redhat.com>
Cc: Developers <qemu-devel@nongnu.org>,
Michael Roth <mdroth@linux.vnet.ibm.com>
Subject: Re: [PATCH v2] qga-win: Free GMatchInfo properly
Date: Thu, 10 Jun 2021 19:08:36 +0300 [thread overview]
Message-ID: <CAJ28CFR0CBAsq4WokeW_OG8gG2UFGSL3H0UB-p2FgXxH3pjhbg@mail.gmail.com> (raw)
In-Reply-To: <YMI3gundDsLZq1lw@redhat.com>
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On Thu, Jun 10, 2021 at 7:02 PM Daniel P. Berrangé <berrange@redhat.com>
wrote:
> On Thu, Jun 10, 2021 at 06:58:11PM +0300, Kostiantyn Kostiuk wrote:
> > The g_regex_match function creates match_info even if it
> > returns FALSE. So we should always call g_match_info_free.
> > A better solution is using g_autoptr for match_info variable.
> >
> > Signed-off-by: Kostiantyn Kostiuk <konstantin@daynix.com>
> > ---
> > qga/commands-win32.c | 3 +--
> > 1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > diff --git a/qga/commands-win32.c b/qga/commands-win32.c
> > index 300b87c859..785a5cc6b2 100644
> > --- a/qga/commands-win32.c
> > +++ b/qga/commands-win32.c
> > @@ -2494,7 +2494,7 @@ GuestDeviceInfoList *qmp_guest_get_devices(Error
> **errp)
> > continue;
> > }
> > for (j = 0; hw_ids[j] != NULL; j++) {
> > - GMatchInfo *match_info;
> > + g_autoptr(GMatchInfo) match_info;
>
> This should be initialized to NULL otherwise...
>
> > GuestDeviceIdPCI *id;
> > if (!g_regex_match(device_pci_re, hw_ids[j], 0,
> &match_info)) {
> > continue;
>
> this continue will trigger freeing of unintialized memory
>
But we always call match_info, so match_info is always initialized.
The g_regex_match function creates match_info even if it returns FALSE.
>
> Essentially all g_auto* variables should be init to NULL
> at all times, even if it currently looks harmless.
>
> > @@ -2511,7 +2511,6 @@ GuestDeviceInfoList *qmp_guest_get_devices(Error
> **errp)
> > id->vendor_id = g_ascii_strtoull(vendor_id, NULL, 16);
> > id->device_id = g_ascii_strtoull(device_id, NULL, 16);
> >
> > - g_match_info_free(match_info);
> > break;
> > }
> > if (skip) {
>
> Regards,
> Daniel
> --
> |: https://berrange.com -o-
> https://www.flickr.com/photos/dberrange :|
> |: https://libvirt.org -o-
> https://fstop138.berrange.com :|
> |: https://entangle-photo.org -o-
> https://www.instagram.com/dberrange :|
>
>
Best wishes,
Kostiantyn Kostiuk
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next prev parent reply other threads:[~2021-06-10 16:10 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-10 15:58 [PATCH v2] qga-win: Free GMatchInfo properly Kostiantyn Kostiuk
2021-06-10 16:02 ` Daniel P. Berrangé
2021-06-10 16:08 ` Konstantin Kostiuk [this message]
2021-06-10 16:14 ` Daniel P. Berrangé
2021-07-14 7:26 ` Konstantin Kostiuk
2021-07-28 7:54 ` Konstantin Kostiuk
2021-07-28 11:58 ` [PATCH-for-6.1 " Philippe Mathieu-Daudé
2021-06-10 16:04 ` [PATCH " Philippe Mathieu-Daudé
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