[PATCH 3.16 175/366] drm/msm: fix leak in failed get_pages

Ben Hutchings
2018-10-14T23:25:15Z

From: Prakash Kamliya <pkamliya@codeaurora.org>

commit 62e3a3e342af3c313ab38603811ecdb1fcc79edb upstream.

get_pages doesn't keep a reference of the pages allocated
when it fails later in the code path. This can lead to
a memory leak. Keep reference of the allocated pages so
that it can be freed when msm_gem_free_object gets called
later during cleanup.

Signed-off-by: Prakash Kamliya <pkamliya@codeaurora.org>
Signed-off-by: Sharat Masetty <smasetty@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/gpu/drm/msm/msm_gem.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)

--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -83,14 +83,17 @@ static struct page **get_pages(struct dr
return p;
}

+ msm_obj->pages = p;
+
msm_obj->sgt = drm_prime_pages_to_sg(p, npages);
if (IS_ERR(msm_obj->sgt)) {
+ void *ptr = ERR_CAST(msm_obj->sgt);
+
dev_err(dev->dev, "failed to allocate sgt\n");
- return ERR_CAST(msm_obj->sgt);
+ msm_obj->sgt = NULL;
+ return ptr;
}

- msm_obj->pages = p;
-
/* For non-cached buffers, ensure the new pages are clean
* because display controller, GPU, etc. are not coherent:
*/
@@ -113,7 +116,10 @@ static void put_pages(struct drm_gem_obj
if (msm_obj->flags & (MSM_BO_WC|MSM_BO_UNCACHED))
dma_unmap_sg(obj->dev->dev, msm_obj->sgt->sgl,
msm_obj->sgt->nents, DMA_BIDIRECTIONAL);
- sg_free_table(msm_obj->sgt);
+
+ if (msm_obj->sgt)
+ sg_free_table(msm_obj->sgt);
+
kfree(msm_obj->sgt);

if (iommu_present(&platform_bus_type))