| Message ID | 20190322152657.13752-2-jean-philippe.brucker@arm.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Neil Armstrong |
| Headers | show |
| Series | [1/2] drm/meson: Fix invalid pointer in meson_drv_unbind() | expand |
Hi Jean-Philippe, Le 22/03/2019 16:26, Jean-Philippe Brucker a écrit : > meson_drv_unbind() doesn't unregister the IRQ handler, which can lead to > use-after-free if the IRQ fires after unbind: > > [ 64.656876] Unable to handle kernel paging request at virtual address ffff000011706dbc > ... > [ 64.662001] pc : meson_irq+0x18/0x30 [meson_drm] > > I'm assuming that a similar problem could happen on the error path of > bind(), so uninstall the IRQ handler there as well. > > Fixes: bbbe775ec5b5 ("drm: Add support for Amlogic Meson Graphic Controller") > Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> > --- > drivers/gpu/drm/meson/meson_drv.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) Thanks for working on this, Acked-by: Neil Armstrong <narmstrong@baylibre.com> I'll push it on drm-misc-fixes > > diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c > index 7e85802c5398..8a4ebcb6405c 100644 > --- a/drivers/gpu/drm/meson/meson_drv.c > +++ b/drivers/gpu/drm/meson/meson_drv.c > @@ -337,12 +337,14 @@ static int meson_drv_bind_master(struct device *dev, bool has_components) > > ret = drm_dev_register(drm, 0); > if (ret) > - goto free_drm; > + goto uninstall_irq; > > drm_fbdev_generic_setup(drm, 32); > > return 0; > > +uninstall_irq: > + drm_irq_uninstall(drm); > free_drm: > drm_dev_put(drm); > > @@ -367,6 +369,7 @@ static void meson_drv_unbind(struct device *dev) > } > > drm_dev_unregister(drm); > + drm_irq_uninstall(drm); > drm_kms_helper_poll_fini(drm); > drm_mode_config_cleanup(drm); > drm_dev_put(drm); >
diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c index 7e85802c5398..8a4ebcb6405c 100644 --- a/drivers/gpu/drm/meson/meson_drv.c +++ b/drivers/gpu/drm/meson/meson_drv.c @@ -337,12 +337,14 @@ static int meson_drv_bind_master(struct device *dev, bool has_components) ret = drm_dev_register(drm, 0); if (ret) - goto free_drm; + goto uninstall_irq; drm_fbdev_generic_setup(drm, 32); return 0; +uninstall_irq: + drm_irq_uninstall(drm); free_drm: drm_dev_put(drm); @@ -367,6 +369,7 @@ static void meson_drv_unbind(struct device *dev) } drm_dev_unregister(drm); + drm_irq_uninstall(drm); drm_kms_helper_poll_fini(drm); drm_mode_config_cleanup(drm); drm_dev_put(drm);
meson_drv_unbind() doesn't unregister the IRQ handler, which can lead to use-after-free if the IRQ fires after unbind: [ 64.656876] Unable to handle kernel paging request at virtual address ffff000011706dbc ... [ 64.662001] pc : meson_irq+0x18/0x30 [meson_drm] I'm assuming that a similar problem could happen on the error path of bind(), so uninstall the IRQ handler there as well. Fixes: bbbe775ec5b5 ("drm: Add support for Amlogic Meson Graphic Controller") Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> --- drivers/gpu/drm/meson/meson_drv.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)