From 24013314be6ee4ee456114a671e9fa3461323de8 Mon Sep 17 00:00:00 2001
From: Rob Clark <robdclark@chromium.org>
Date: Wed, 30 Nov 2022 10:57:47 -0800
Subject: [PATCH] drm/shmem-helper: Remove errant put in error path
Git-commit: 24013314be6ee4ee456114a671e9fa3461323de8
Patch-mainline: v6.1
References: git-fixes
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@syzkaller.appspotmail.com
Fixes: 2194a63a818d ("drm: Add library for shmem backed GEM objects")
Cc: stable@vger.kernel.org
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221130185748.357410-2-robdclark@gmail.com
Acked-by: Takashi Iwai <tiwai@suse.de>
---
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
@@ -622,10 +622,8 @@ int drm_gem_shmem_mmap(struct drm_gem_sh
}
ret = drm_gem_shmem_get_pages(shmem);
- if (ret) {
- drm_gem_vm_close(vma);
+ if (ret)
return ret;
- }
vma->vm_flags |= VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);