From: Dominique Martinet dominique.martinet@atmark-techno.com
[ Upstream commit 868c9ddc182bc6728bb380cbfb3170734f72c599 ]
This is a follow-up on 5f89468e2f06 ("swiotlb: manipulate orig_addr when tlb_addr has offset") which fixed unaligned dma mappings, making sure the following overflows are caught:
- offset of the start of the slot within the device bigger than requested address' offset, in other words if the base address given in swiotlb_tbl_map_single to create the mapping (orig_addr) was after the requested address for the sync (tlb_offset) in the same block:
|------------------------------------------| block <----------------------------> mapped part of the block ^ orig_addr ^ invalid tlb_addr for sync
- if the resulting offset was bigger than the allocation size this one could happen if the mapping was not until the end. e.g.
|------------------------------------------| block <---------------------> mapped part of the block ^ ^ orig_addr invalid tlb_addr
Both should never happen so print a warning and bail out without trying to adjust the sizes/offsets: the first one could try to sync from orig_addr to whatever is left of the requested size, but the later really has nothing to sync there...
Signed-off-by: Dominique Martinet dominique.martinet@atmark-techno.com Cc: Konrad Rzeszutek Wilk konrad.wilk@oracle.com Reviewed-by: Bumyong Lee <bumyong.lee@samsung.com Cc: Chanho Park chanho61.park@samsung.com Cc: Christoph Hellwig hch@lst.de Signed-off-by: Konrad Rzeszutek Wilk konrad@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/dma/swiotlb.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-)
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index e50df8d8f87e..23f8d0b168c5 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -354,13 +354,27 @@ static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size size_t alloc_size = mem->slots[index].alloc_size; unsigned long pfn = PFN_DOWN(orig_addr); unsigned char *vaddr = phys_to_virt(tlb_addr); - unsigned int tlb_offset; + unsigned int tlb_offset, orig_addr_offset;
if (orig_addr == INVALID_PHYS_ADDR) return;
- tlb_offset = (tlb_addr & (IO_TLB_SIZE - 1)) - - swiotlb_align_offset(dev, orig_addr); + tlb_offset = tlb_addr & (IO_TLB_SIZE - 1); + orig_addr_offset = swiotlb_align_offset(dev, orig_addr); + if (tlb_offset < orig_addr_offset) { + dev_WARN_ONCE(dev, 1, + "Access before mapping start detected. orig offset %u, requested offset %u.\n", + orig_addr_offset, tlb_offset); + return; + } + + tlb_offset -= orig_addr_offset; + if (tlb_offset > alloc_size) { + dev_WARN_ONCE(dev, 1, + "Buffer overflow detected. Allocation size: %zu. Mapping size: %zu+%u.\n", + alloc_size, size, tlb_offset); + return; + }
orig_addr += tlb_offset; alloc_size -= tlb_offset;