FAILED: patch "[PATCH] fbdev: kyro: Release WC setup on registration failure" failed to apply to 6.6-stable tree

FAILED: patch "[PATCH] fbdev: kyro: Release WC setup on registration failure" failed to apply to 6.6-stable tree

[Sasha Levin]

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x d3bc005a62945aec57059201092b12b7c955e5a7
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '20261107053413-failed-6.6-d3bc005a6294@kernel.org' --subject-prefix 'PATCH 6.6.y' 'HEAD^..'

Thanks,
Sasha

------------------ original commit in Linus's tree ------------------

From d3bc005a62945aec57059201092b12b7c955e5a7 Mon Sep 17 00:00:00 2001
From: Myeonghun Pak <mhun512@gmail.com>
Date: Mon, 14 Sep 2026 20:52:43 -0400
Subject: [PATCH] fbdev: kyro: Release WC setup on registration failure

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.

Cc: stable@vger.kernel.org
Assisted-by: LLM
Co-developed-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
---
 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
index c237389888229..94d6af54e6c46 100644
--- a/drivers/video/fbdev/kyro/fbdev.c
+++ b/drivers/video/fbdev/kyro/fbdev.c
@@ -765,7 +765,7 @@ 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);
 
-- 
2.53.0