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