From: Rick Edgecombe rick.p.edgecombe@intel.com

mainline inclusion from mainline-v6.9-rc1 commit b9fa16949d18e06bdf728a560f5c8af56d2bdcaf category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9QGIS CVE: CVE-2024-35939

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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On TDX it is possible for the untrusted host to cause set_memory_encrypted() or set_memory_decrypted() to fail such that an error is returned and the resulting memory is shared. Callers need to take care to handle these errors to avoid returning decrypted (shared) memory to the page allocator, which could lead to functional or security issues.

DMA could free decrypted/shared pages if dma_set_decrypted() fails. This should be a rare case. Just leak the pages in this case instead of freeing them.

Signed-off-by: Rick Edgecombe rick.p.edgecombe@intel.com Signed-off-by: Christoph Hellwig hch@lst.de

Conflicts: kernel/dma/direct.c [Context conflicts.] Signed-off-by: Jinjiang Tu tujinjiang@huawei.com --- kernel/dma/direct.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index f13493c54629..9f08d81ce1f8 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -243,7 +243,7 @@ void *dma_direct_alloc(struct device *dev, size_t size, err = set_memory_decrypted((unsigned long)ret, PFN_UP(size)); if (err) - goto out_free_pages; + goto out_leak_pages; }

memset(ret, 0, size); @@ -270,6 +270,8 @@ void *dma_direct_alloc(struct device *dev, size_t size, out_free_pages: __dma_direct_free_pages(dev, page, size); return NULL; +out_leak_pages: + return NULL; }

void dma_direct_free(struct device *dev, size_t size, @@ -333,7 +335,7 @@ struct page *dma_direct_alloc_pages(struct device *dev, size_t size, ret = page_address(page); if (force_dma_unencrypted(dev)) { if (set_memory_decrypted((unsigned long)ret, PFN_UP(size))) - goto out_free_pages; + goto out_leak_pages; } memset(ret, 0, size); *dma_handle = phys_to_dma_direct(dev, page_to_phys(page)); @@ -341,6 +343,8 @@ struct page *dma_direct_alloc_pages(struct device *dev, size_t size, out_free_pages: __dma_direct_free_pages(dev, page, size); return NULL; +out_leak_pages: + return NULL; }

void dma_direct_free_pages(struct device *dev, size_t size,