This is a note to let you know that I've just added the patch titled
fbdev: Fix invalid page access after closing deferred I/O devices
to the 6.1-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:
fbdev-fix-invalid-page-access-after-closing-deferred-i-o-devices.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 3efc61d95259956db25347e2a9562c3e54546e20 Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@xxxxxxx>
Date: Sun, 29 Jan 2023 09:28:56 +0100
Subject: fbdev: Fix invalid page access after closing deferred I/O devices
From: Takashi Iwai <tiwai@xxxxxxx>
commit 3efc61d95259956db25347e2a9562c3e54546e20 upstream.
When a fbdev with deferred I/O is once opened and closed, the dirty
pages still remain queued in the pageref list, and eventually later
those may be processed in the delayed work. This may lead to a
corruption of pages, hitting an Oops.
This patch makes sure to cancel the delayed work and clean up the
pageref list at closing the device for addressing the bug. A part of
the cleanup code is factored out as a new helper function that is
called from the common fb_release().
Reviewed-by: Patrik Jakobsson <patrik.r.jakobsson@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Tested-by: Miko Larsson <mikoxyzzz@xxxxxxxxx>
Fixes: 56c134f7f1b5 ("fbdev: Track deferred-I/O pages in pageref struct")
Reviewed-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20230129082856.22113-1-tiwai@xxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/video/fbdev/core/fb_defio.c | 10 +++++++++-
drivers/video/fbdev/core/fbmem.c | 4 ++++
include/linux/fb.h | 1 +
3 files changed, 14 insertions(+), 1 deletion(-)
--- a/drivers/video/fbdev/core/fb_defio.c
+++ b/drivers/video/fbdev/core/fb_defio.c
@@ -313,7 +313,7 @@ void fb_deferred_io_open(struct fb_info
}
EXPORT_SYMBOL_GPL(fb_deferred_io_open);
-void fb_deferred_io_cleanup(struct fb_info *info)
+void fb_deferred_io_release(struct fb_info *info)
{
struct fb_deferred_io *fbdefio = info->fbdefio;
struct page *page;
@@ -327,6 +327,14 @@ void fb_deferred_io_cleanup(struct fb_in
page = fb_deferred_io_page(info, i);
page->mapping = NULL;
}
+}
+EXPORT_SYMBOL_GPL(fb_deferred_io_release);
+
+void fb_deferred_io_cleanup(struct fb_info *info)
+{
+ struct fb_deferred_io *fbdefio = info->fbdefio;
+
+ fb_deferred_io_release(info);
kvfree(info->pagerefs);
mutex_destroy(&fbdefio->lock);
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -1453,6 +1453,10 @@ __releases(&info->lock)
struct fb_info * const info = file->private_data;
lock_fb_info(info);
+#if IS_ENABLED(CONFIG_FB_DEFERRED_IO)
+ if (info->fbdefio)
+ fb_deferred_io_release(info);
+#endif
if (info->fbops->fb_release)
info->fbops->fb_release(info,1);
module_put(info->fbops->owner);
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -662,6 +662,7 @@ extern int fb_deferred_io_init(struct f
extern void fb_deferred_io_open(struct fb_info *info,
struct inode *inode,
struct file *file);
+extern void fb_deferred_io_release(struct fb_info *info);
extern void fb_deferred_io_cleanup(struct fb_info *info);
extern int fb_deferred_io_fsync(struct file *file, loff_t start,
loff_t end, int datasync);
Patches currently in stable-queue which might be from tiwai@xxxxxxx are
queue-6.1/fbdev-fix-invalid-page-access-after-closing-deferred-i-o-devices.patch
queue-6.1/alsa-hda-do-not-unset-preset-when-cleaning-up-codec.patch
queue-6.1/alsa-usb-audio-add-fixed_rate-quirk-for-jbl-quantum6.patch
