6.6-stable review patch. If anyone has any objections, please let me know.
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From: Shanker Donthineni sdonthineni@nvidia.com
commit 89a2d212bdb4bc29bed8e7077abe054b801137ea upstream.
When CONFIG_DMA_DIRECT_REMAP is enabled, atomic pool pages are remapped via dma_common_contiguous_remap() using the supplied pgprot. Currently, the mapping uses pgprot_dmacoherent(PAGE_KERNEL), which leaves the memory encrypted on systems with memory encryption enabled (e.g., ARM CCA Realms).
This can cause the DMA layer to fail or crash when accessing the memory, as the underlying physical pages are not configured as expected.
Fix this by requesting a decrypted mapping in the vmap() call: pgprot_decrypted(pgprot_dmacoherent(PAGE_KERNEL))
This ensures that atomic pool memory is consistently mapped unencrypted.
Cc: stable@vger.kernel.org Signed-off-by: Shanker Donthineni sdonthineni@nvidia.com Reviewed-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Link: https://lore.kernel.org/r/20250811181759.998805-1-sdonthineni@nvidia.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/dma/pool.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/kernel/dma/pool.c +++ b/kernel/dma/pool.c @@ -102,8 +102,8 @@ static int atomic_pool_expand(struct gen
#ifdef CONFIG_DMA_DIRECT_REMAP addr = dma_common_contiguous_remap(page, pool_size, - pgprot_dmacoherent(PAGE_KERNEL), - __builtin_return_address(0)); + pgprot_decrypted(pgprot_dmacoherent(PAGE_KERNEL)), + __builtin_return_address(0)); if (!addr) goto free_page; #else