In arm_smmu_alloc_cd_tables(), the error check following the
dma_alloc_coherent() for cd_table->l2.l1tab incorrectly tests
cd_table->l2.l2ptrs.

This means an allocation failure for l1tab goes undetected, causing
the function to return 0 (success) erroneously.

Correct the check to test cd_table->l2.l1tab.

Fixes: e3b1be2e73db ("iommu/arm-smmu-v3: Reorganize struct arm_smmu_ctx_desc_cfg")
Signed-off-by: Daniel Mentz <danielmentz@google.com>
Signed-off-by: Ryan Huang <tzukui@google.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index 2a8b46b948f0..9780f40ba3e6 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1464,7 +1464,7 @@ static int arm_smmu_alloc_cd_tables(struct arm_smmu_master *master)
 		cd_table->l2.l1tab = dma_alloc_coherent(smmu->dev, l1size,
 							&cd_table->cdtab_dma,
 							GFP_KERNEL);
-		if (!cd_table->l2.l2ptrs) {
+		if (!cd_table->l2.l1tab) {
 			ret = -ENOMEM;
 			goto err_free_l2ptrs;
 		}
-- 
2.51.2.1041.gc1ab5b90ca-goog

On Fri, 07 Nov 2025 11:09:17 -0800, Ryan Huang wrote:
> In arm_smmu_alloc_cd_tables(), the error check following the
> dma_alloc_coherent() for cd_table->l2.l1tab incorrectly tests
> cd_table->l2.l2ptrs.
> 
> This means an allocation failure for l1tab goes undetected, causing
> the function to return 0 (success) erroneously.
> 
> [...]

Applied to iommu (arm/smmu/updates), thanks!

[1/1] iommu/arm-smmu-v3: Fix error check in arm_smmu_alloc_cd_tables
      https://git.kernel.org/iommu/c/5941f0e0c1e0

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev

On Fri, Nov 07, 2025 at 11:09:17AM -0800, Ryan Huang wrote:
> In arm_smmu_alloc_cd_tables(), the error check following the
> dma_alloc_coherent() for cd_table->l2.l1tab incorrectly tests
> cd_table->l2.l2ptrs.
> 
> This means an allocation failure for l1tab goes undetected, causing
> the function to return 0 (success) erroneously.
> 
> Correct the check to test cd_table->l2.l1tab.
> 
> Fixes: e3b1be2e73db ("iommu/arm-smmu-v3: Reorganize struct arm_smmu_ctx_desc_cfg")
> Signed-off-by: Daniel Mentz <danielmentz@google.com>
> Signed-off-by: Ryan Huang <tzukui@google.com>
 
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>

On Fri, Nov 07, 2025 at 11:09:17AM -0800, Ryan Huang wrote:
> In arm_smmu_alloc_cd_tables(), the error check following the
> dma_alloc_coherent() for cd_table->l2.l1tab incorrectly tests
> cd_table->l2.l2ptrs.
> 
> This means an allocation failure for l1tab goes undetected, causing
> the function to return 0 (success) erroneously.
> 
> Correct the check to test cd_table->l2.l1tab.
> 
> Fixes: e3b1be2e73db ("iommu/arm-smmu-v3: Reorganize struct arm_smmu_ctx_desc_cfg")
> Signed-off-by: Daniel Mentz <danielmentz@google.com>
> Signed-off-by: Ryan Huang <tzukui@google.com>
> ---
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 

Reviewed-by: Pranjal Shrivastava <praan@google.com>

Thanks for the fix!
-Praan

On Fri, Nov 07, 2025 at 11:09:17AM -0800, Ryan Huang wrote:
> In arm_smmu_alloc_cd_tables(), the error check following the
> dma_alloc_coherent() for cd_table->l2.l1tab incorrectly tests
> cd_table->l2.l2ptrs.
> 
> This means an allocation failure for l1tab goes undetected, causing
> the function to return 0 (success) erroneously.
> 
> Correct the check to test cd_table->l2.l1tab.
> 
> Fixes: e3b1be2e73db ("iommu/arm-smmu-v3: Reorganize struct arm_smmu_ctx_desc_cfg")
> Signed-off-by: Daniel Mentz <danielmentz@google.com>
> Signed-off-by: Ryan Huang <tzukui@google.com>
> ---
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason