Dear Zhouyi,
Am 10.02.22 um 07:58 schrieb Zhouyi Zhou:
In function do_remove_conflicting_framebuffers, if device is NULL, there
will be null pointer reference. The patch add a check to the if expression.
Signed-off-by: Zhouyi Zhou <zhouzhouyi@xxxxxxxxx>
---
Dear Linux folks
I discover this bug in the PowerPC VM provided by
Open source lab of Oregon State University:
https://lkml.org/lkml/2022/2/8/1145
I found that the root cause of null device field is in offb_init_fb:
info = framebuffer_alloc(sizeof(u32) * 16, NULL);
I have tested the patch in the PowerPC VM. Hope my patch can be correct.
Many Thanks
Zhouyi
--
drivers/video/fbdev/core/fbmem.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index 34d6bb1bf82e..422b1fc01722 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -1579,7 +1579,7 @@ static void do_remove_conflicting_framebuffers(struct apertures_struct *a,
* If it's not a platform device, at least print a warning. A
* fix would add code to remove the device from the system.
*/
- if (dev_is_platform(device)) {
+ if (device && dev_is_platform(device)) {
registered_fb[i]->forced_out = true;
platform_device_unregister(to_platform_device(device));
} else {
Looks reasonable.
Acked-by: Paul Menzel <pmenzel@xxxxxxxxxxxxx>
Kind regards,
Paul
PS: Please note, this should be unrelated to my problem though, as I
didn’t use linux-next. (Let’s continue in the other thread though.)
