diff mbox series

[v2,03/11] drm/tegra: vic: Fix DMA API misuse

Message ID 6b86f6e530b504a5eee864af10e2ae1570d7b645.1639157090.git.robin.murphy@arm.com (mailing list archive)
State New, archived
Headers show
Series None | expand

Commit Message

Robin Murphy Dec. 10, 2021, 5:54 p.m. UTC
Upon failure, dma_alloc_coherent() returns NULL. If that does happen,
passing some uninitialised stack contents to dma_mapping_error() - which
belongs to a different API in the first place - has precious little
chance of detecting it.

Also include the correct header, because the fragile transitive
inclusion currently providing it is going to break soon.

Fixes: 20e7dce255e9 ("drm/tegra: Remove memory allocation from Falcon library")
CC: Thierry Reding <thierry.reding@gmail.com>
CC: Mikko Perttunen <mperttunen@nvidia.com>
CC: dri-devel@lists.freedesktop.org
Signed-off-by: Robin Murphy <robin.murphy@arm.com>

---

It also doesn't appear to handle failure of the tegra_drm_alloc() path
either, but that's a loose thread I have no desire to pull on... ;)

v2: Resend as part of the series, originally posted separately here:

https://lore.kernel.org/dri-devel/2703882439344010e33bf21ecd63cf9e5e6dc00d.1637781007.git.robin.murphy@arm.com/

 drivers/gpu/drm/tegra/vic.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

Comments

Thierry Reding Dec. 16, 2021, 8:55 a.m. UTC | #1
On Fri, Dec 10, 2021 at 05:54:44PM +0000, Robin Murphy wrote:
> Upon failure, dma_alloc_coherent() returns NULL. If that does happen,
> passing some uninitialised stack contents to dma_mapping_error() - which
> belongs to a different API in the first place - has precious little
> chance of detecting it.
> 
> Also include the correct header, because the fragile transitive
> inclusion currently providing it is going to break soon.
> 
> Fixes: 20e7dce255e9 ("drm/tegra: Remove memory allocation from Falcon library")
> CC: Thierry Reding <thierry.reding@gmail.com>
> CC: Mikko Perttunen <mperttunen@nvidia.com>
> CC: dri-devel@lists.freedesktop.org
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> 
> ---
> 
> It also doesn't appear to handle failure of the tegra_drm_alloc() path
> either, but that's a loose thread I have no desire to pull on... ;)
> 
> v2: Resend as part of the series, originally posted separately here:
> 
> https://lore.kernel.org/dri-devel/2703882439344010e33bf21ecd63cf9e5e6dc00d.1637781007.git.robin.murphy@arm.com/
> 
>  drivers/gpu/drm/tegra/vic.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)

Applied, thanks. I've also fixed up the missing failure handling for
tegra_drm_alloc(), which was actually quite trivial to do.

Thierry
diff mbox series

Patch

diff --git a/drivers/gpu/drm/tegra/vic.c b/drivers/gpu/drm/tegra/vic.c
index c02010ff2b7f..da4af5371991 100644
--- a/drivers/gpu/drm/tegra/vic.c
+++ b/drivers/gpu/drm/tegra/vic.c
@@ -5,6 +5,7 @@ 
 
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/dma-mapping.h>
 #include <linux/host1x.h>
 #include <linux/iommu.h>
 #include <linux/module.h>
@@ -232,10 +233,8 @@  static int vic_load_firmware(struct vic *vic)
 
 	if (!client->group) {
 		virt = dma_alloc_coherent(vic->dev, size, &iova, GFP_KERNEL);
-
-		err = dma_mapping_error(vic->dev, iova);
-		if (err < 0)
-			return err;
+		if (!virt)
+			return -ENOMEM;
 	} else {
 		virt = tegra_drm_alloc(tegra, size, &iova);
 	}