On 5/4/26 17:24, Dmitry Baryshkov wrote:
Mixing devm and drmm functions will result in a use-after-free on msm
driver teardown if userspace keeps a reference on the drm device:
The WB connector data will be destroyed because of the use of
devm_kzalloc()), while the usersoace still can try interacting with the
extra ) on devm_kzalloc())
typo: userspace
Otherwise the description looks good to me and the two typos can be
fixed when merging, so:
Reviewed-by: [email protected]
But should wait for at least an ack from Laurent as the person
originally requesting an extended description.
John.
WB connector (which uses drmm_ functions).
Change dpu_writeback_init() to use drmm_.
Fixes: 0b37ac63fc9d ("drm/msm/dpu: use drmm_writeback_connector_init()")
Reported-by: Christophe JAILLET <[email protected]>
Closes:
https://lore.kernel.org/r/[email protected]
Signed-off-by: Dmitry Baryshkov <[email protected]>
---
drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
index 7545c0293efb..6f2370c9dd98 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_writeback.c
@@ -5,6 +5,7 @@
#include <drm/drm_edid.h>
#include <drm/drm_framebuffer.h>
+#include <drm/drm_managed.h>
#include "dpu_writeback.h"
@@ -125,7 +126,7 @@ int dpu_writeback_init(struct drm_device *dev, struct drm_encoder *enc,
struct dpu_wb_connector *dpu_wb_conn;
int rc = 0;
- dpu_wb_conn = devm_kzalloc(dev->dev, sizeof(*dpu_wb_conn), GFP_KERNEL);
+ dpu_wb_conn = drmm_kzalloc(dev, sizeof(*dpu_wb_conn), GFP_KERNEL);
if (!dpu_wb_conn)
return -ENOMEM;
