From 586847b98e20ab02212ca5c1fc46680384e68a28 Mon Sep 17 00:00:00 2001 From: Rob Clark Date: Wed, 30 Nov 2022 10:57:47 -0800 Subject: [PATCH] drm/shmem-helper: Remove errant put in error path 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@syzkaller.appspotmail.com Fixes: 2194a63a818d ("drm: Add library for shmem backed GEM objects") Cc: stable@vger.kernel.org Signed-off-by: Rob Clark Reviewed-by: Daniel Vetter Signed-off-by: Javier Martinez Canillas Link: https://patchwork.freedesktop.org/patch/msgid/20221130185748.357410-2-robdclark@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/drm_gem_shmem_helper.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c index 904fc893c905..026319abeec4 100644 --- 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_shmem_object *shmem, struct vm_area_struct } 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);