This is a note to let you know that I've just added the patch titled
drm: mxsfb: Fix NULL pointer dereference crash on unload
to the 5.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-mxsfb-fix-null-pointer-dereference-crash-on-unload.patch
and it can be found in the queue-5.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 3cfc183052c3dbf8eae57b6c1685dab00ed3db4a Mon Sep 17 00:00:00 2001
From: Marek Vasut <marex@xxxxxxx>
Date: Sat, 16 Oct 2021 23:04:46 +0200
Subject: drm: mxsfb: Fix NULL pointer dereference crash on unload
From: Marek Vasut <marex@xxxxxxx>
commit 3cfc183052c3dbf8eae57b6c1685dab00ed3db4a upstream.
The mxsfb->crtc.funcs may already be NULL when unloading the driver,
in which case calling mxsfb_irq_disable() via drm_irq_uninstall() from
mxsfb_unload() leads to NULL pointer dereference.
Since all we care about is masking the IRQ and mxsfb->base is still
valid, just use that to clear and mask the IRQ.
Fixes: ae1ed00932819 ("drm: mxsfb: Stop using DRM simple display pipeline helper")
Signed-off-by: Marek Vasut <marex@xxxxxxx>
Cc: Daniel Abrecht <public@xxxxxxxxxxxxxxxx>
Cc: Emil Velikov <emil.l.velikov@xxxxxxxxx>
Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Cc: Sam Ravnborg <sam@xxxxxxxxxxxx>
Cc: Stefan Agner <stefan@xxxxxxxx>
Signed-off-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20211016210446.171616-1-marex@xxxxxxx
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/mxsfb/mxsfb_drv.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/mxsfb/mxsfb_drv.c
+++ b/drivers/gpu/drm/mxsfb/mxsfb_drv.c
@@ -268,7 +268,11 @@ static void mxsfb_irq_disable(struct drm
struct mxsfb_drm_private *mxsfb = drm->dev_private;
mxsfb_enable_axi_clk(mxsfb);
- mxsfb->crtc.funcs->disable_vblank(&mxsfb->crtc);
+
+ /* Disable and clear VBLANK IRQ */
+ writel(CTRL1_CUR_FRAME_DONE_IRQ_EN, mxsfb->base + LCDC_CTRL1 + REG_CLR);
+ writel(CTRL1_CUR_FRAME_DONE_IRQ, mxsfb->base + LCDC_CTRL1 + REG_CLR);
+
mxsfb_disable_axi_clk(mxsfb);
}
Patches currently in stable-queue which might be from marex@xxxxxxx are
queue-5.14/drm-mxsfb-fix-null-pointer-dereference-crash-on-unload.patch
