This is a note to let you know that I've just added the patch titled
drm: Fix potential null-ptr-deref due to drmm_mode_config_init()
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:
drm-fix-potential-null-ptr-deref-due-to-drmm_mode_co.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.
commit 7857da320e7e6973d2b80fff226af3c8d0110562
Author: Shang XiaoJing <shangxiaojing@xxxxxxxxxx>
Date: Fri Nov 18 10:16:51 2022 +0800
drm: Fix potential null-ptr-deref due to drmm_mode_config_init()
[ Upstream commit 834c23e4f798dcdc8af251b3c428ceef94741991 ]
drmm_mode_config_init() will call drm_mode_create_standard_properties()
and won't check the ret value. When drm_mode_create_standard_properties()
failed due to alloc, property will be a NULL pointer and may causes the
null-ptr-deref. Fix the null-ptr-deref by adding the ret value check.
Found null-ptr-deref while testing insert module bochs:
general protection fault, probably for non-canonical address
0xdffffc000000000c: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000060-0x0000000000000067]
CPU: 3 PID: 249 Comm: modprobe Not tainted 6.1.0-rc1+ #364
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014
RIP: 0010:drm_object_attach_property+0x73/0x3c0 [drm]
Call Trace:
<TASK>
__drm_connector_init+0xb6c/0x1100 [drm]
bochs_pci_probe.cold.11+0x4cb/0x7fe [bochs]
pci_device_probe+0x17d/0x340
really_probe+0x1db/0x5d0
__driver_probe_device+0x1e7/0x250
driver_probe_device+0x4a/0x120
__driver_attach+0xcd/0x2c0
bus_for_each_dev+0x11a/0x1b0
bus_add_driver+0x3d7/0x500
driver_register+0x18e/0x320
do_one_initcall+0xc4/0x3e0
do_init_module+0x1b4/0x630
load_module+0x5dca/0x7230
__do_sys_finit_module+0x100/0x170
do_syscall_64+0x3f/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7ff65af9f839
Fixes: 6b4959f43a04 ("drm/atomic: atomic plane properties")
Signed-off-by: Shang XiaoJing <shangxiaojing@xxxxxxxxxx>
Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20221118021651.2460-1-shangxiaojing@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c
index 688c8afe0bf17..8525ef8515406 100644
--- a/drivers/gpu/drm/drm_mode_config.c
+++ b/drivers/gpu/drm/drm_mode_config.c
@@ -399,6 +399,8 @@ static void drm_mode_config_init_release(struct drm_device *dev, void *ptr)
*/
int drmm_mode_config_init(struct drm_device *dev)
{
+ int ret;
+
mutex_init(&dev->mode_config.mutex);
drm_modeset_lock_init(&dev->mode_config.connection_mutex);
mutex_init(&dev->mode_config.idr_mutex);
@@ -420,7 +422,11 @@ int drmm_mode_config_init(struct drm_device *dev)
init_llist_head(&dev->mode_config.connector_free_list);
INIT_WORK(&dev->mode_config.connector_free_work, drm_connector_free_work_fn);
- drm_mode_create_standard_properties(dev);
+ ret = drm_mode_create_standard_properties(dev);
+ if (ret) {
+ drm_mode_config_cleanup(dev);
+ return ret;
+ }
/* Just to be sure */
dev->mode_config.num_fb = 0;
