This is a note to let you know that I've just added the patch titled
drm: correctly restore mappings if drm_open fails
to the 3.8-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-correctly-restore-mappings-if-drm_open-fails.patch
and it can be found in the queue-3.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From a8ec3a662921220fc058ed6f7f3674697876d218 Mon Sep 17 00:00:00 2001
From: Ilija Hadzic <[email protected]>
Date: Tue, 2 Apr 2013 09:56:10 -0400
Subject: drm: correctly restore mappings if drm_open fails
From: Ilija Hadzic <[email protected]>
commit a8ec3a662921220fc058ed6f7f3674697876d218 upstream.
If first drm_open fails, the error-handling path will
incorrectly restore inode's mapping to NULL. This can
cause the crash later on. Fix by separately storing
away mapping pointers that drm_open can touch and
restore each from its own respective variable if the
call fails.
Fixes: https://bugzilla.novell.com/show_bug.cgi?id=807850
(thanks to Michal Hocko for investigating investigating and
finding the root cause of the bug)
Reference:
http://lists.freedesktop.org/archives/dri-devel/2013-March/036564.html
v2: Use one variable to store file and inode mapping
since they are the same at the function entry.
Fix spelling mistakes in commit message.
v3: Add reference to the original bug report.
Reported-by: Marco Munderloh <[email protected]>
Tested-by: Marco Munderloh <[email protected]>
Signed-off-by: Ilija Hadzic <[email protected]>
Cc: Michal Hocko <[email protected]>
Signed-off-by: Dave Airlie <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/gpu/drm/drm_fops.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -123,6 +123,7 @@ int drm_open(struct inode *inode, struct
int retcode = 0;
int need_setup = 0;
struct address_space *old_mapping;
+ struct address_space *old_imapping;
minor = idr_find(&drm_minors_idr, minor_id);
if (!minor)
@@ -137,6 +138,7 @@ int drm_open(struct inode *inode, struct
if (!dev->open_count++)
need_setup = 1;
mutex_lock(&dev->struct_mutex);
+ old_imapping = inode->i_mapping;
old_mapping = dev->dev_mapping;
if (old_mapping == NULL)
dev->dev_mapping = &inode->i_data;
@@ -159,8 +161,8 @@ int drm_open(struct inode *inode, struct
err_undo:
mutex_lock(&dev->struct_mutex);
- filp->f_mapping = old_mapping;
- inode->i_mapping = old_mapping;
+ filp->f_mapping = old_imapping;
+ inode->i_mapping = old_imapping;
iput(container_of(dev->dev_mapping, struct inode, i_data));
dev->dev_mapping = old_mapping;
mutex_unlock(&dev->struct_mutex);
Patches currently in stable-queue which might be from
[email protected] are
queue-3.8/drm-correctly-restore-mappings-if-drm_open-fails.patch
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