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authorTakashi Iwai <tiwai@suse.de>2023-01-29 09:28:56 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-02-23 08:55:13 +0100
commit87b9802ca824fcee7915e717e9a60471af62e8e9 (patch)
tree5815b7cc450f4c8b4d706bc4ecf17bfa629fb36b
parent9a95fc04261f8328912896972b9291792edafdf0 (diff)
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fbdev: Fix invalid page access after closing deferred I/O devices
[ Upstream commit 3efc61d95259956db25347e2a9562c3e54546e20 ] 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@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Tested-by: Miko Larsson <mikoxyzzz@gmail.com> Fixes: 56c134f7f1b5 ("fbdev: Track deferred-I/O pages in pageref struct") Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/20230129082856.22113-1-tiwai@suse.de Stable-dep-of: 33cd6ea9c067 ("fbdev: flush deferred IO before closing") Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--drivers/video/fbdev/core/fb_defio.c10
-rw-r--r--drivers/video/fbdev/core/fbmem.c4
-rw-r--r--include/linux/fb.h1
3 files changed, 14 insertions, 1 deletions
diff --git a/drivers/video/fbdev/core/fb_defio.c b/drivers/video/fbdev/core/fb_defio.c
index 5faeca61d3dd..b3f41f432ec2 100644
--- a/drivers/video/fbdev/core/fb_defio.c
+++ b/drivers/video/fbdev/core/fb_defio.c
@@ -292,7 +292,7 @@ void fb_deferred_io_open(struct fb_info *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;
@@ -306,6 +306,14 @@ void fb_deferred_io_cleanup(struct fb_info *info)
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);
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index 1b288a613a6e..ec7a883715e3 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -1454,6 +1454,10 @@ __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);
diff --git a/include/linux/fb.h b/include/linux/fb.h
index b322d30f6225..433cddf8442b 100644
--- a/include/linux/fb.h
+++ b/include/linux/fb.h
@@ -675,6 +675,7 @@ extern int fb_deferred_io_init(struct fb_info *info);
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);