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authorWill Deacon <will@kernel.org>2024-03-08 15:28:25 +0000
committerChristoph Hellwig <hch@lst.de>2024-03-13 11:39:22 -0700
commit823353b7cf0ea9dfb09f5181d5fb2825d727200b (patch)
tree26da8a6c2a3eef07150016a861b31105783a2602 /kernel/dma
parent04867a7a33324c9c562ee7949dbcaab7aaad1fb4 (diff)
swiotlb: Enforce page alignment in swiotlb_alloc()
When allocating pages from a restricted DMA pool in swiotlb_alloc(), the buffer address is blindly converted to a 'struct page *' that is returned to the caller. In the unlikely event of an allocation bug, page-unaligned addresses are not detected and slots can silently be double-allocated. Add a simple check of the buffer alignment in swiotlb_alloc() to make debugging a little easier if something has gone wonky. Signed-off-by: Will Deacon <will@kernel.org> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Reviewed-by: Petr Tesarik <petr.tesarik1@huawei-partners.com> Tested-by: Nicolin Chen <nicolinc@nvidia.com> Tested-by: Michael Kelley <mhklinux@outlook.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'kernel/dma')
-rw-r--r--kernel/dma/swiotlb.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 980a7ec70418..88114433f1e6 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -1689,6 +1689,12 @@ struct page *swiotlb_alloc(struct device *dev, size_t size)
return NULL;
tlb_addr = slot_addr(pool->start, index);
+ if (unlikely(!PAGE_ALIGNED(tlb_addr))) {
+ dev_WARN_ONCE(dev, 1, "Cannot allocate pages from non page-aligned swiotlb addr 0x%pa.\n",
+ &tlb_addr);
+ swiotlb_release_slots(dev, tlb_addr);
+ return NULL;
+ }
return pfn_to_page(PFN_DOWN(tlb_addr));
}