This is a note to let you know that I've just added the patch titled
drm/shmem-helper: Remove another errant put in error path
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-shmem-helper-remove-another-errant-put-in-error-path.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.
>From ee9adb7a45516cfa536ca92253d7ae59d56db9e4 Mon Sep 17 00:00:00 2001
From: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
Date: Mon, 9 Jan 2023 00:13:11 +0300
Subject: drm/shmem-helper: Remove another errant put in error path
From: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
commit ee9adb7a45516cfa536ca92253d7ae59d56db9e4 upstream.
drm_gem_shmem_mmap() doesn't own reference in error code path, resulting
in the dma-buf shmem GEM object getting prematurely freed leading to a
later use-after-free.
Fixes: f49a51bfdc8e ("drm/shme-helpers: Fix dma_buf_mmap forwarding bug")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@xxxxxxxxxxxxx>
Reviewed-by: Rob Clark <robdclark@xxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20230108211311.3950107-1-dmitry.osipenko@xxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/drm_gem_shmem_helper.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -622,11 +622,14 @@ int drm_gem_shmem_mmap(struct drm_gem_sh
int ret;
if (obj->import_attach) {
- /* Drop the reference drm_gem_mmap_obj() acquired.*/
- drm_gem_object_put(obj);
vma->vm_private_data = NULL;
+ ret = dma_buf_mmap(obj->dma_buf, vma, 0);
+
+ /* Drop the reference drm_gem_mmap_obj() acquired.*/
+ if (!ret)
+ drm_gem_object_put(obj);
- return dma_buf_mmap(obj->dma_buf, vma, 0);
+ return ret;
}
ret = drm_gem_shmem_get_pages(shmem);
Patches currently in stable-queue which might be from dmitry.osipenko@xxxxxxxxxxxxx are
queue-6.1/drm-msm-gem-prevent-blocking-within-shrinker-loop.patch
queue-6.1/drm-shmem-helper-remove-another-errant-put-in-error-path.patch
queue-6.1/drm-virtio-pass-correct-device-to-dma_sync_sgtable_f.patch
queue-6.1/drm-panfrost-don-t-sync-rpm-suspension-after-mmu-flu.patch
