[PATCH 3.13 067/187] drm/tilcdc: fix double kfree

Kamal Mostafa
2014-09-15T22:13:46Z

From: =?UTF-8?q?Guido=20Mart=C3=ADnez?= <guido@vanguardiasur.com.ar>

commit c9a3ad25eddfdb898114a9d73cdb4c3472d9dfca upstream.

display_timings_release calls kfree on the display_timings object passed
to it. Calling kfree after it is wrong. SLUB debug showed the following
warning:

=============================================================================
BUG kmalloc-64 (Tainted: G W ): Object already free
-----------------------------------------------------------------------------

Disabling lock debugging due to kernel taint
INFO: Allocated in of_get_display_timings+0x2c/0x214 age=601 cpu=0
pid=884
__slab_alloc.constprop.79+0x2e0/0x33c
kmem_cache_alloc+0xac/0xdc
of_get_display_timings+0x2c/0x214
panel_probe+0x7c/0x314 [tilcdc]
platform_drv_probe+0x18/0x48
[..snip..]
INFO: Freed in panel_destroy+0x18/0x3c [tilcdc] age=0 cpu=0 pid=907
__slab_free+0x34/0x330
panel_destroy+0x18/0x3c [tilcdc]
tilcdc_unload+0xd0/0x118 [tilcdc]
drm_dev_unregister+0x24/0x98
[..snip..]

Signed-off-by: Guido Martínez <guido@vanguardiasur.com.ar>
Tested-by: Darren Etheridge <detheridge@ti.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
---
drivers/gpu/drm/tilcdc/tilcdc_panel.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/tilcdc/tilcdc_panel.c b/drivers/gpu/drm/tilcdc/tilcdc_panel.c
index 1943b2f..b085dcc 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_panel.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_panel.c
@@ -286,10 +286,8 @@ static void panel_destroy(struct tilcdc_module *mod)
{
struct panel_module *panel_mod = to_panel_module(mod);

- if (panel_mod->timings) {
+ if (panel_mod->timings)
display_timings_release(panel_mod->timings);
- kfree(panel_mod->timings);
- }

tilcdc_module_cleanup(mod);
kfree(panel_mod->info);
--
1.9.1