38 lines
1.4 KiB
Diff
38 lines
1.4 KiB
Diff
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References: bsc#958007 XSA-164
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MSI-X: avoid array overrun upon MSI-X table writes
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pt_msix_init() allocates msix->msix_entry[] to just cover
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msix->total_entries entries. While pci_msix_readl() resorts to reading
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physical memory for out of bounds reads, pci_msix_writel() so far
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simply accessed/corrupted unrelated memory.
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pt_iomem_map()'s call to cpu_register_physical_memory() registers a
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page granular region, which is necessary as the Pending Bit Array may
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share space with the MSI-X table (but nothing else is allowed to). This
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also explains why pci_msix_readl() actually honors out of bounds reads,
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but pci_msi_writel() doesn't need to.
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This is XSA-164.
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Signed-off-by: Jan Beulich <jbeulich@suse.com>
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Index: xen-4.6.0-testing/tools/qemu-xen-traditional-dir-remote/hw/pt-msi.c
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===================================================================
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--- xen-4.6.0-testing.orig/tools/qemu-xen-traditional-dir-remote/hw/pt-msi.c
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+++ xen-4.6.0-testing/tools/qemu-xen-traditional-dir-remote/hw/pt-msi.c
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@@ -440,6 +440,13 @@ static void pci_msix_writel(void *opaque
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return;
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}
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+ if ( addr - msix->mmio_base_addr >= msix->total_entries * 16 )
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+ {
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+ PT_LOG("Error: Out of bounds write to MSI-X table,"
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+ " addr %016"PRIx64"\n", addr);
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+ return;
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+ }
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+
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entry_nr = (addr - msix->mmio_base_addr) / 16;
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entry = &msix->msix_entry[entry_nr];
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offset = ((addr - msix->mmio_base_addr) % 16) / 4;
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