From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zhenyu Wang Subject: Re: [PATCH] drm/i915/gvt: fix memory leak in intel_vgpu_ioctl() Date: Wed, 8 Aug 2018 15:23:20 +0800 Message-ID: <20180808072320.GP22630@zhen-hp.sh.intel.com> References: <1533256879-10220-1-git-send-email-wang.yi59@zte.com.cn> Reply-To: Zhenyu Wang Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1217129921==" Return-path: In-Reply-To: <1533256879-10220-1-git-send-email-wang.yi59@zte.com.cn> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Yi Wang Cc: zhong.weidong@zte.com.cn, airlied@linux.ie, intel-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, rodrigo.vivi@intel.com, jiang.biao2@zte.com.cn, intel-gvt-dev@lists.freedesktop.org, zhi.a.wang@intel.com List-Id: intel-gfx@lists.freedesktop.org --===============1217129921== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="b0R8ugpUbPHtGZft" Content-Disposition: inline --b0R8ugpUbPHtGZft Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2018.08.03 08:41:19 +0800, Yi Wang wrote: > The 'sparse' variable may leak when return in function > intel_vgpu_ioctl(), and this patch fixes this. >=20 > Signed-off-by: Yi Wang > Reviewed-by: Jiang Biao > --- > drivers/gpu/drm/i915/gvt/kvmgt.c | 3 +++ > 1 file changed, 3 insertions(+) >=20 > diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/= kvmgt.c > index df4e4a0..6a6f199 100644 > --- a/drivers/gpu/drm/i915/gvt/kvmgt.c > +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c > @@ -1200,6 +1200,7 @@ static long intel_vgpu_ioctl(struct mdev_device *md= ev, unsigned int cmd, > return ret; > break; > default: > + kfree(sparse); > return -EINVAL; > } > } > @@ -1215,6 +1216,7 @@ static long intel_vgpu_ioctl(struct mdev_device *md= ev, unsigned int cmd, > sizeof(info), caps.buf, > caps.size)) { > kfree(caps.buf); > + kfree(sparse); > return -EFAULT; > } > info.cap_offset =3D sizeof(info); > @@ -1223,6 +1225,7 @@ static long intel_vgpu_ioctl(struct mdev_device *md= ev, unsigned int cmd, > kfree(caps.buf); > } > =20 > + kfree(sparse); Unfortunately this would cause a double-free error in normal path, as we tried to free sparse after use to add caps. So may be better to fix free in error path and move normal free of sparse in final point, e.g diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kv= mgt.c index 68df9aa88890..47b897b6ea93 100644 --- a/drivers/gpu/drm/i915/gvt/kvmgt.c +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c @@ -1257,11 +1257,13 @@ static long intel_vgpu_ioctl(struct mdev_device *md= ev, unsigned int cmd, &sparse->header, sizeof(*sparse) + (sparse->nr_areas * sizeof(*sparse->areas))); - kfree(sparse); - if (ret) + if (ret) { + kfree(sparse); return ret; + } break; default: + kfree(sparse); return -EINVAL; } } @@ -1277,6 +1279,7 @@ static long intel_vgpu_ioctl(struct mdev_device *mdev= , unsigned int cmd, sizeof(info), caps.buf, caps.size)) { kfree(caps.buf); + kfree(sparse); return -EFAULT; } info.cap_offset =3D sizeof(info); @@ -1285,6 +1288,7 @@ static long intel_vgpu_ioctl(struct mdev_device *mdev= , unsigned int cmd, kfree(caps.buf); } =20 + kfree(sparse); return copy_to_user((void __user *)arg, &info, minsz) ? -EFAULT : 0; } else if (cmd =3D=3D VFIO_DEVICE_GET_IRQ_INFO) { --=20 Open Source Technology Center, Intel ltd. $gpg --keyserver wwwkeys.pgp.net --recv-keys 4D781827 --b0R8ugpUbPHtGZft Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EARECAB0WIQTXuabgHDW6LPt9CICxBBozTXgYJwUCW2qaaAAKCRCxBBozTXgY J1/iAKCXRN8Z4nUqYzICnKwjDuszqfNHzgCeMtnse5wwkdV+bxW7mTmN1m0M0J4= =Nbo5 -----END PGP SIGNATURE----- --b0R8ugpUbPHtGZft-- --===============1217129921== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KZHJpLWRldmVs IG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlz dHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVsCg== --===============1217129921==--