File 0237-exec-Respect-as_tranlsate_internal-.patch of Package qemu.10255

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File 0237-exec-Respect-as_tranlsate_internal-.patch of Package qemu.10255

From 7bfb4dae630bc59750be8addf36bf36bc88460c5 Mon Sep 17 00:00:00 2001
From: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Date: Mon, 16 Mar 2015 22:35:54 -0700
Subject: [PATCH] exec: Respect as_tranlsate_internal length clamp

address_space_translate_internal will clamp the *plen length argument
based on the size of the memory region being queried. The iommu walker
logic in addresss_space_translate was ignoring this by discarding the
post fn call value of *plen. Fix by just always using *plen as the
length argument throughout the fn, removing the len local variable.

This fixes a bootloader bug when a single elf section spans multiple
QEMU memory regions.

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Message-Id: <1426570554-15940-1-git-send-email-peter.crosthwaite@xilinx.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit c3c1bb99d1c11978d9ce94d1bdcf0705378c1459)
[BR: BSC#969121 CVE-2015-8817]
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
 exec.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/exec.c b/exec.c
index 7d74973604..a58be1a9ff 100644
--- a/exec.c
+++ b/exec.c
@@ -358,7 +358,6 @@ MemoryRegion *address_space_translate(AddressSpace *as, hwaddr addr,
     IOMMUTLBEntry iotlb;
     MemoryRegionSection *section;
     MemoryRegion *mr;
-    hwaddr len = *plen;
 
     for (;;) {
         section = address_space_translate_internal(as->dispatch, addr, &addr, plen, true);
@@ -371,7 +370,7 @@ MemoryRegion *address_space_translate(AddressSpace *as, hwaddr addr,
         iotlb = mr->iommu_ops->translate(mr, addr);
         addr = ((iotlb.translated_addr & ~iotlb.addr_mask)
                 | (addr & iotlb.addr_mask));
-        len = MIN(len, (addr | iotlb.addr_mask) - addr + 1);
+        *plen = MIN(*plen, (addr | iotlb.addr_mask) - addr + 1);
         if (!(iotlb.perm & (1 << is_write))) {
             mr = &io_mem_unassigned;
             break;
@@ -382,10 +381,9 @@ MemoryRegion *address_space_translate(AddressSpace *as, hwaddr addr,
 
     if (memory_access_is_direct(mr, is_write)) {
         hwaddr page = ((addr & TARGET_PAGE_MASK) + TARGET_PAGE_SIZE) - addr;
-        len = MIN(page, len);
+        *plen = MIN(page, *plen);
     }
 
-    *plen = len;
     *xlat = addr;
     return mr;
 }

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File 0237-exec-Respect-as_tranlsate_internal-.patch of Package qemu.10255

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