[PATCH] fbdev: kyro: Release WC setup on registration failure

[Myeonghun Pak]

If register_framebuffer() fails, kyrofb_probe() frees the framebuffer
without releasing its write-combining range. Release the range before
freeing the framebuffer. Earlier failures still skip this cleanup.

The missing cleanup already exists in the initial Git import, before
the conversion from mtrr_add() to arch_phys_wc_add().

This issue was identified during our ongoing static-analysis research
while reviewing kernel code.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Cc: stable@xxxxxxxxxxxxxxx
Assisted-by: LLM
Co-developed-by: Ijae Kim <ae878000@xxxxxxxxx>
Signed-off-by: Ijae Kim <ae878000@xxxxxxxxx>
Signed-off-by: Myeonghun Pak <mhun512@xxxxxxxxx>
---
 drivers/video/fbdev/kyro/fbdev.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/kyro/fbdev.c b/drivers/video/fbdev/kyro/fbdev.c
--- a/drivers/video/fbdev/kyro/fbdev.c
+++ b/drivers/video/fbdev/kyro/fbdev.c
@@ -759,7 +759,7 @@ static int kyrofb_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	fb_memset_io(info->screen_base, 0, size);
 
 	if (register_framebuffer(info) < 0)
-		goto out_free_fb;
+		goto out_free_wc;
 
 	fb_info(info, "%s frame buffer device, at %dx%d@%d using %ldk/%ldk of VRAM\n",
 		info->fix.id,
@@ -776,6 +776,8 @@ static int kyrofb_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	return 0;
 
+out_free_wc:
+	arch_phys_wc_del(currentpar->wc_cookie);
 out_free_fb:
 	framebuffer_release(info);
 
-- 
2.51.0