Le 12/02/2025 à 09:53, Thomas Zimmermann a écrit :
Am 12.02.25 um 09:49 schrieb José Expósito:
If the driver initialization fails, the vkms_exit() function might
access an uninitialized or freed default_config pointer and it might
double free it.
Fix both possible errors by initializing default_config only when the
driver initialization succeeded.
Reported-by: Louis Chauvet <louis.chau...@bootlin.com>
Link: https://lore.kernel.org/all/Z5uDHcCmAwiTsGte@louis-chauvet-laptop/
Fixes: 2df7af93fdad ("drm/vkms: Add vkms_config type")
Signed-off-by: José Expósito <jose.exposit...@gmail.com>
Reviewed-by: Thomas Zimmermann <tzimmrem...@suse.de>
Reviewed-by: Louis Chauvet <louis.chau...@bootlin.com>
lore.kernel.org is broken currently, to avoid doing mistakes, I will
wait for it to be working again so I can apply your patch using dim+b4.
(I removed danvet.vet...@ffwl.ch from CC, the mail server rejected the mail)
Thanks!
Louis Chauvet
Thanks for posting this patch separately.
Best regards
Thomas
---
drivers/gpu/drm/vkms/vkms_drv.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c
index 7c142bfc3bd9..b6de91134a22 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.c
+++ b/drivers/gpu/drm/vkms/vkms_drv.c
@@ -235,17 +235,19 @@ static int __init vkms_init(void)
if (!config)
return -ENOMEM;
- default_config = config;
-
config->cursor = enable_cursor;
config->writeback = enable_writeback;
config->overlay = enable_overlay;
ret = vkms_create(config);
- if (ret)
+ if (ret) {
kfree(config);
+ return ret;
+ }
- return ret;
+ default_config = config;
+
+ return 0;
}
static void vkms_destroy(struct vkms_config *config)
@@ -269,9 +271,10 @@ static void vkms_destroy(struct vkms_config *config)
static void __exit vkms_exit(void)
{
- if (default_config->dev)
- vkms_destroy(default_config);
+ if (!default_config)
+ return;
+ vkms_destroy(default_config);
kfree(default_config);
}
--
Louis Chauvet, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
