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 { -- 2.25.1
