This is a note to let you know that I've just added the patch titled
drm/shmem-helper: Remove errant put in error path
to the 5.4-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-shmem-helper-remove-errant-put-in-error-path.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 24013314be6ee4ee456114a671e9fa3461323de8 Mon Sep 17 00:00:00 2001
From: Rob Clark <robdclark@xxxxxxxxxxxx>
Date: Wed, 30 Nov 2022 10:57:47 -0800
Subject: drm/shmem-helper: Remove errant put in error path
From: Rob Clark <robdclark@xxxxxxxxxxxx>
commit 24013314be6ee4ee456114a671e9fa3461323de8 upstream.
drm_gem_shmem_mmap() doesn't own this reference, resulting in the GEM
object getting prematurely freed leading to a later use-after-free.
Link: https://syzkaller.appspot.com/bug?extid=c8ae65286134dd1b800d
Reported-by: syzbot+c8ae65286134dd1b800d@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 2194a63a818d ("drm: Add library for shmem backed GEM objects")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Signed-off-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20221130185748.357410-2-robdclark@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/drm_gem_shmem_helper.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -554,10 +554,8 @@ int drm_gem_shmem_mmap(struct file *filp
shmem = to_drm_gem_shmem_obj(vma->vm_private_data);
ret = drm_gem_shmem_get_pages(shmem);
- if (ret) {
- drm_gem_vm_close(vma);
+ if (ret)
return ret;
- }
/* VM_PFNMAP was set by drm_gem_mmap() */
vma->vm_flags &= ~VM_PFNMAP;
Patches currently in stable-queue which might be from robdclark@xxxxxxxxxxxx are
queue-5.4/drm-shmem-helper-remove-errant-put-in-error-path.patch
