| Message ID | 20201117072103.GA1111239@mwanda (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | drm/kmb: Fix possible oops in probe error handling | expand |
Hi Dan, > -----Original Message----- > From: Dan Carpenter <dan.carpenter@oracle.com> > Sent: Monday, November 16, 2020 11:21 PM > To: Chrisanthus, Anitha <anitha.chrisanthus@intel.com> > Cc: Dea, Edmund J <edmund.j.dea@intel.com>; David Airlie <airlied@linux.ie>; > Daniel Vetter <daniel@ffwll.ch>; Sam Ravnborg <sam@ravnborg.org>; dri- > devel@lists.freedesktop.org; kernel-janitors@vger.kernel.org > Subject: [PATCH] drm/kmb: Fix possible oops in probe error handling > > If kmb_dsi_init() fails the error handling will dereference an error > pointer which will cause an Oops. > > Fixes: 7f7b96a8a0a1 ("drm/kmb: Add support for KeemBay Display") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > --- > drivers/gpu/drm/kmb/kmb_drv.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/kmb/kmb_drv.c > b/drivers/gpu/drm/kmb/kmb_drv.c > index a31a840ce634..8c43b136765c 100644 > --- a/drivers/gpu/drm/kmb/kmb_drv.c > +++ b/drivers/gpu/drm/kmb/kmb_drv.c > @@ -504,7 +504,7 @@ static int kmb_probe(struct platform_device *pdev) > if (IS_ERR(kmb->kmb_dsi)) { > drm_err(&kmb->drm, "failed to initialize DSI\n"); > ret = PTR_ERR(kmb->kmb_dsi); > - goto err_free1; > + goto err_clear_drvdata; > } dsi host is registered earlier, it needs to be unregistered, original code is correct. Anitha > > kmb->kmb_dsi->dev = &dsi_pdev->dev; > @@ -540,8 +540,9 @@ static int kmb_probe(struct platform_device *pdev) > drm_crtc_cleanup(&kmb->crtc); > drm_mode_config_cleanup(&kmb->drm); > err_free1: > - dev_set_drvdata(dev, NULL); > kmb_dsi_host_unregister(kmb->kmb_dsi); > + err_clear_drvdata: > + dev_set_drvdata(dev, NULL); > > return ret; > } > -- > 2.28.0
On Fri, Nov 20, 2020 at 01:29:45AM +0000, Chrisanthus, Anitha wrote: > Hi Dan, > > > -----Original Message----- > > From: Dan Carpenter <dan.carpenter@oracle.com> > > Sent: Monday, November 16, 2020 11:21 PM > > To: Chrisanthus, Anitha <anitha.chrisanthus@intel.com> > > Cc: Dea, Edmund J <edmund.j.dea@intel.com>; David Airlie <airlied@linux.ie>; > > Daniel Vetter <daniel@ffwll.ch>; Sam Ravnborg <sam@ravnborg.org>; dri- > > devel@lists.freedesktop.org; kernel-janitors@vger.kernel.org > > Subject: [PATCH] drm/kmb: Fix possible oops in probe error handling > > > > If kmb_dsi_init() fails the error handling will dereference an error > > pointer which will cause an Oops. > > > > Fixes: 7f7b96a8a0a1 ("drm/kmb: Add support for KeemBay Display") > > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> > > --- > > drivers/gpu/drm/kmb/kmb_drv.c | 5 +++-- > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/kmb/kmb_drv.c > > b/drivers/gpu/drm/kmb/kmb_drv.c > > index a31a840ce634..8c43b136765c 100644 > > --- a/drivers/gpu/drm/kmb/kmb_drv.c > > +++ b/drivers/gpu/drm/kmb/kmb_drv.c > > @@ -504,7 +504,7 @@ static int kmb_probe(struct platform_device *pdev) > > if (IS_ERR(kmb->kmb_dsi)) { ^^^^^^^^^^^^ We check that this is an error pointer. > > drm_err(&kmb->drm, "failed to initialize DSI\n"); > > ret = PTR_ERR(kmb->kmb_dsi); > > - goto err_free1; ^^^^^^^^^^^^^^^ We go to err_free1. > > + goto err_clear_drvdata; > > } > dsi host is registered earlier, it needs to be unregistered, original code is correct. > > Anitha > > > > kmb->kmb_dsi->dev = &dsi_pdev->dev; > > @@ -540,8 +540,9 @@ static int kmb_probe(struct platform_device *pdev) > > drm_crtc_cleanup(&kmb->crtc); > > drm_mode_config_cleanup(&kmb->drm); > > err_free1: ^^^^^^^^^ Which is here. > > - dev_set_drvdata(dev, NULL); > > kmb_dsi_host_unregister(kmb->kmb_dsi); ^^^^^^^^^^^^ And then we crash. Probably my commit message was not clear enough. I will change the commit message and resend. regards, dan carpenter > > + err_clear_drvdata: > > + dev_set_drvdata(dev, NULL); > > > > return ret; > > } > > -- > > 2.28.0
diff --git a/drivers/gpu/drm/kmb/kmb_drv.c b/drivers/gpu/drm/kmb/kmb_drv.c index a31a840ce634..8c43b136765c 100644 --- a/drivers/gpu/drm/kmb/kmb_drv.c +++ b/drivers/gpu/drm/kmb/kmb_drv.c @@ -504,7 +504,7 @@ static int kmb_probe(struct platform_device *pdev) if (IS_ERR(kmb->kmb_dsi)) { drm_err(&kmb->drm, "failed to initialize DSI\n"); ret = PTR_ERR(kmb->kmb_dsi); - goto err_free1; + goto err_clear_drvdata; } kmb->kmb_dsi->dev = &dsi_pdev->dev; @@ -540,8 +540,9 @@ static int kmb_probe(struct platform_device *pdev) drm_crtc_cleanup(&kmb->crtc); drm_mode_config_cleanup(&kmb->drm); err_free1: - dev_set_drvdata(dev, NULL); kmb_dsi_host_unregister(kmb->kmb_dsi); + err_clear_drvdata: + dev_set_drvdata(dev, NULL); return ret; }
If kmb_dsi_init() fails the error handling will dereference an error pointer which will cause an Oops. Fixes: 7f7b96a8a0a1 ("drm/kmb: Add support for KeemBay Display") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> --- drivers/gpu/drm/kmb/kmb_drv.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)