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* [PATCH] iommufd/selftest: Fix dmabuf leak in iommufd_test_dmabuf_get()
@ 2026-07-07  3:06 YeeLi
  2026-07-13 16:16 ` Jason Gunthorpe
  0 siblings, 1 reply; 2+ messages in thread
From: YeeLi @ 2026-07-07  3:06 UTC (permalink / raw)
  To: jgg, kevin.tian, joro, will, robin.murphy; +Cc: iommu, linux-kernel, yeeli

From: yeeli <seven.yi.lee@gmail.com>

iommufd/selftest: Fix dmabuf leak in iommufd_test_dmabuf_get()

When dma_buf_export() succeeds but dma_buf_fd() fails (e.g. -EMFILE
from fd exhaustion), the dmabuf is leaked with no dma_buf_put() called.

Reproducer: exhaust fd table near RLIMIT_NOFILE, then repeatedly call
IOMMU_TEST_OP_DMABUF_GET — htop shows unbounded memory growth.

Fix by calling dma_buf_put(dmabuf) on error and returning directly.

Signed-off-by: yeeli <seven.yi.lee@gmail.com>
---
 drivers/iommu/iommufd/selftest.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index af07c642a526..7340d9f3c62b 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -2023,7 +2023,12 @@ static int iommufd_test_dmabuf_get(struct iommufd_ucmd *ucmd,
 		goto err_free;
 	}
 
-	return dma_buf_fd(dmabuf, open_flags);
+	rc = dma_buf_fd(dmabuf, open_flags);
+	if (rc < 0) {
+		dma_buf_put(dmabuf);
+		return rc;
+	}
+	return rc;
 
 err_free:
 	kfree(priv->memory);
-- 
2.34.1


^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH] iommufd/selftest: Fix dmabuf leak in iommufd_test_dmabuf_get()
  2026-07-07  3:06 [PATCH] iommufd/selftest: Fix dmabuf leak in iommufd_test_dmabuf_get() YeeLi
@ 2026-07-13 16:16 ` Jason Gunthorpe
  0 siblings, 0 replies; 2+ messages in thread
From: Jason Gunthorpe @ 2026-07-13 16:16 UTC (permalink / raw)
  To: YeeLi; +Cc: kevin.tian, joro, will, robin.murphy, iommu, linux-kernel

On Tue, Jul 07, 2026 at 11:06:35AM +0800, YeeLi wrote:
> From: yeeli <seven.yi.lee@gmail.com>
> 
> iommufd/selftest: Fix dmabuf leak in iommufd_test_dmabuf_get()
> 
> When dma_buf_export() succeeds but dma_buf_fd() fails (e.g. -EMFILE
> from fd exhaustion), the dmabuf is leaked with no dma_buf_put() called.
> 
> Reproducer: exhaust fd table near RLIMIT_NOFILE, then repeatedly call
> IOMMU_TEST_OP_DMABUF_GET — htop shows unbounded memory growth.
> 
> Fix by calling dma_buf_put(dmabuf) on error and returning directly.
> 
> Signed-off-by: yeeli <seven.yi.lee@gmail.com>
> ---
>  drivers/iommu/iommufd/selftest.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)

Applied thanks

Jason

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2026-07-13 16:16 UTC | newest]

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2026-07-07  3:06 [PATCH] iommufd/selftest: Fix dmabuf leak in iommufd_test_dmabuf_get() YeeLi
2026-07-13 16:16 ` Jason Gunthorpe

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