Thread (71 messages) 71 messages, 6 authors, 6h ago
HOTtoday REVIEWED: 2 (1M)
Revisions (3)
  1. v4 [diff vs current]
  2. v5 [diff vs current]
  3. v6 current

[PATCH v6 12/20] dma-pool: fix page leak in atomic_pool_expand() cleanup

From: "Aneesh Kumar K.V (Arm)" <aneesh.kumar@kernel.org>
Date: 2026-06-04 08:42:12
Also in: linux-arm-kernel, linux-coco, linux-iommu, linux-s390, lkml
Subsystem: dma mapping helpers, the rest · Maintainers: Marek Szyprowski, Linus Torvalds

atomic_pool_expand() frees the allocated pages from the remove_mapping
error path only when CONFIG_DMA_DIRECT_REMAP is enabled.

When CONFIG_DMA_DIRECT_REMAP is disabled, failures after page allocation,
such as gen_pool_add_virt(), jump to remove_mapping and return without
freeing the pages.

Move __free_pages(page, order) out of the CONFIG_DMA_DIRECT_REMAP block so
that cleanup paths always release the allocation.

Tested-by: Michael Kelley <redacted>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Aneesh Kumar K.V (Arm) <aneesh.kumar@kernel.org>
---
 kernel/dma/pool.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c
index be78474a6c49..e7df8d279e75 100644
--- a/kernel/dma/pool.c
+++ b/kernel/dma/pool.c
@@ -146,9 +146,9 @@ static int atomic_pool_expand(struct dma_gen_pool *dma_pool, size_t pool_size,
 #ifdef CONFIG_DMA_DIRECT_REMAP
 	dma_common_free_remap(addr, pool_size);
 free_page:
+#endif
 	if (!leak_pages)
 		__free_pages(page, order);
-#endif
 out:
 	return ret;
 }
-- 
2.43.0

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