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| author | Christoph Hellwig <hch@lst.de> | 2021-11-09 15:41:01 +0100 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2021-12-07 12:47:38 +0100 |
| commit | a90cf30437489343b8386ae87b4827b6d6c3ed50 (patch) | |
| tree | 65dd1ad2ed4fac84b87a36df276ebf385ce48232 /kernel/dma/direct.c | |
| parent | 5570449b6876f215d49ac4db9ccce6ff7aa1e20a (diff) | |
| download | linux-a90cf30437489343b8386ae87b4827b6d6c3ed50.tar.gz linux-a90cf30437489343b8386ae87b4827b6d6c3ed50.tar.bz2 linux-a90cf30437489343b8386ae87b4827b6d6c3ed50.zip | |
dma-direct: always leak memory that can't be re-encrypted
We must never let unencrypted memory go back into the general page pool.
So if we fail to set it back to encrypted when freeing DMA memory, leak
the memory instead and warn the user.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Diffstat (limited to 'kernel/dma/direct.c')
| -rw-r--r-- | kernel/dma/direct.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 996ba4edb2fa..d7a489be4847 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -84,9 +84,14 @@ static int dma_set_decrypted(struct device *dev, void *vaddr, size_t size) static int dma_set_encrypted(struct device *dev, void *vaddr, size_t size) { + int ret; + if (!force_dma_unencrypted(dev)) return 0; - return set_memory_encrypted((unsigned long)vaddr, 1 << get_order(size)); + ret = set_memory_encrypted((unsigned long)vaddr, 1 << get_order(size)); + if (ret) + pr_warn_ratelimited("leaking DMA memory that can't be re-encrypted\n"); + return ret; } static void __dma_direct_free_pages(struct device *dev, struct page *page, @@ -261,7 +266,6 @@ done: return ret; out_encrypt_pages: - /* If memory cannot be re-encrypted, it must be leaked */ if (dma_set_encrypted(dev, page_address(page), size)) return NULL; out_free_pages: @@ -307,7 +311,8 @@ void dma_direct_free(struct device *dev, size_t size, } else { if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_CLEAR_UNCACHED)) arch_dma_clear_uncached(cpu_addr, size); - dma_set_encrypted(dev, cpu_addr, 1 << page_order); + if (dma_set_encrypted(dev, cpu_addr, 1 << page_order)) + return; } __dma_direct_free_pages(dev, dma_direct_to_page(dev, dma_addr), size); @@ -361,7 +366,8 @@ void dma_direct_free_pages(struct device *dev, size_t size, dma_free_from_pool(dev, vaddr, size)) return; - dma_set_encrypted(dev, vaddr, 1 << page_order); + if (dma_set_encrypted(dev, vaddr, 1 << page_order)) + return; __dma_direct_free_pages(dev, page, size); } |