From: Greg KH <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org,
alan@lxorguk.ukuu.org.uk,
Thomas Hellstrom <thellstrom@vmware.com>,
Daniel Vetter <daniel.vetter@ffwll.ch>,
Dave Airlie <airlied@redhat.com>
Subject: [04/20] drm: Fix authentication kernel crash
Date: Wed, 01 Feb 2012 12:14:06 -0800 [thread overview]
Message-ID: <20120201201531.431868568@clark.kroah.org> (raw)
In-Reply-To: <20120201210055.GA25374@kroah.com>
2.6.32-longterm review patch. If anyone has any objections, please let me know.
------------------
From: Thomas Hellstrom <thellstrom@vmware.com>
commit 598781d71119827b454fd75d46f84755bca6f0c6 upstream.
If the master tries to authenticate a client using drm_authmagic and
that client has already closed its drm file descriptor,
either wilfully or because it was terminated, the
call to drm_authmagic will dereference a stale pointer into kmalloc'ed memory
and corrupt it.
Typically this results in a hard system hang.
This patch fixes that problem by removing any authentication tokens
(struct drm_magic_entry) open for a file descriptor when that file
descriptor is closed.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/drm_auth.c | 6 +++++-
drivers/gpu/drm/drm_fops.c | 5 +++++
include/drm/drmP.h | 1 +
3 files changed, 11 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/drm_auth.c
+++ b/drivers/gpu/drm/drm_auth.c
@@ -102,7 +102,7 @@ static int drm_add_magic(struct drm_mast
* Searches and unlinks the entry in drm_device::magiclist with the magic
* number hash key, while holding the drm_device::struct_mutex lock.
*/
-static int drm_remove_magic(struct drm_master *master, drm_magic_t magic)
+int drm_remove_magic(struct drm_master *master, drm_magic_t magic)
{
struct drm_magic_entry *pt;
struct drm_hash_item *hash;
@@ -137,6 +137,8 @@ static int drm_remove_magic(struct drm_m
* If there is a magic number in drm_file::magic then use it, otherwise
* searches an unique non-zero magic number and add it associating it with \p
* file_priv.
+ * This ioctl needs protection by the drm_global_mutex, which protects
+ * struct drm_file::magic and struct drm_magic_entry::priv.
*/
int drm_getmagic(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
@@ -174,6 +176,8 @@ int drm_getmagic(struct drm_device *dev,
* \return zero if authentication successed, or a negative number otherwise.
*
* Checks if \p file_priv is associated with the magic number passed in \arg.
+ * This ioctl needs protection by the drm_global_mutex, which protects
+ * struct drm_file::magic and struct drm_magic_entry::priv.
*/
int drm_authmagic(struct drm_device *dev, void *data,
struct drm_file *file_priv)
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -449,6 +449,11 @@ int drm_release(struct inode *inode, str
(long)old_encode_dev(file_priv->minor->device),
dev->open_count);
+ /* Release any auth tokens that might point to this file_priv,
+ (do that under the drm_global_mutex) */
+ if (file_priv->magic)
+ (void) drm_remove_magic(file_priv->master, file_priv->magic);
+
/* if the master has gone away we can't do anything with the lock */
if (file_priv->minor->master)
drm_master_release(dev, filp);
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -1221,6 +1221,7 @@ extern int drm_getmagic(struct drm_devic
struct drm_file *file_priv);
extern int drm_authmagic(struct drm_device *dev, void *data,
struct drm_file *file_priv);
+extern int drm_remove_magic(struct drm_master *master, drm_magic_t magic);
/* Cache management (drm_cache.c) */
void drm_clflush_pages(struct page *pages[], unsigned long num_pages);
next prev parent reply other threads:[~2012-02-01 21:07 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-01 21:00 [00/20] 2.6.32.56-longterm review Greg KH
2012-02-01 20:14 ` [01/20] eCryptfs: Sanitize write counts of /dev/ecryptfs Greg KH
2012-02-01 20:14 ` [02/20] ecryptfs: Improve metadata read failure logging Greg KH
2012-02-01 20:14 ` [03/20] eCryptfs: Make truncate path killable Greg KH
2012-02-01 20:14 ` Greg KH [this message]
2012-02-01 20:14 ` [05/20] crypto: sha512 - make it work, undo percpu message schedule Greg KH
2012-02-01 20:14 ` [06/20] crypto: sha512 - reduce stack usage to safe number Greg KH
2012-02-01 23:42 ` Alexey Dobriyan
2012-02-01 23:52 ` Greg KH
2012-02-02 0:04 ` Herbert Xu
2012-02-02 0:09 ` Greg KH
2012-02-01 20:14 ` [07/20] Revert "ARM: 7220/1: mmc: mmci: Fixup error handling for dma" Greg KH
2012-02-01 20:14 ` [08/20] block: fail SCSI passthrough ioctls on partition devices Greg KH
2012-02-01 20:14 ` [09/20] dm: do not forward ioctls from logical volumes to the underlying device Greg KH
2012-02-01 20:14 ` [10/20] USB: ftdi_sio: fix TIOCSSERIAL baud_base handling Greg KH
2012-02-01 20:14 ` [11/20] USB: ftdi_sio: add PID for TI XDS100v2 / BeagleBone A3 Greg KH
2012-02-01 20:14 ` [12/20] USB: serial: ftdi additional IDs Greg KH
2012-02-01 20:14 ` [13/20] USB: ftdi_sio: Add more identifiers Greg KH
2012-02-01 20:14 ` [14/20] USB: cdc-wdm: updating desc->length must be protected by spin_lock Greg KH
2012-02-01 20:14 ` [15/20] usb: io_ti: Make edge_remove_sysfs_attrs the port_remove method Greg KH
2012-02-01 20:14 ` [16/20] USB: usbsevseg: fix max length Greg KH
2012-02-01 20:14 ` [17/20] hwmon: (f71805f) Fix clamping of temperature limits Greg KH
2012-02-01 20:14 ` [18/20] hwmon: (sht15) fix bad error code Greg KH
2012-02-01 20:14 ` [19/20] USB: serial: CP210x: Added USB-ID for the Link Instruments MSO-19 Greg KH
2012-02-01 20:14 ` [20/20] USB: cp210x: do not map baud rates to B0 Greg KH
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20120201201531.431868568@clark.kroah.org \
--to=gregkh@linuxfoundation.org \
--cc=airlied@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=alan@lxorguk.ukuu.org.uk \
--cc=daniel.vetter@ffwll.ch \
--cc=linux-kernel@vger.kernel.org \
--cc=stable@vger.kernel.org \
--cc=thellstrom@vmware.com \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).