File 0246-exec-use-qemu_ram_ptr_length-to-acc.patch of Package qemu.19799

From: Prasad J Pandit <pjp@fedoraproject.org>
Date: Wed, 12 Jul 2017 18:08:40 +0530
Subject: exec: use qemu_ram_ptr_length to access guest ram

When accessing guest's ram block during DMA operation, use
'qemu_ram_ptr_length' to get ram block pointer. It ensures
that DMA operation of given length is possible; And avoids
any OOB memory access situations.

Reported-by: Alex <broscutamaker@gmail.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Message-Id: <20170712123840.29328-1-ppandit@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 04bf2526ce87f21b32c9acba1c5518708c243ad0)
[FL: BSC#1048902 CVE-2017-11334]
Signed-off-by: Fei Li <fli@suse.com>
---
 exec.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/exec.c b/exec.c
index a50e1488cee832477cb0e44ce360..4579b30e825cef350672f54a35ec 100644
--- a/exec.c
+++ b/exec.c
@@ -2628,7 +2628,7 @@ static MemTxResult address_space_write_continue(AddressSpace *as, hwaddr addr,
         } else {
             addr1 += memory_region_get_ram_addr(mr);
             /* RAM case */
-            ptr = qemu_get_ram_ptr(mr->ram_block, addr1);
+            ptr = qemu_ram_ptr_length(mr->ram_block, addr1, &l);
             memcpy(ptr, buf, l);
             invalidate_and_set_dirty(mr, addr1, l);
         }
@@ -2719,8 +2719,9 @@ MemTxResult address_space_read_continue(AddressSpace *as, hwaddr addr,
             }
         } else {
             /* RAM case */
-            ptr = qemu_get_ram_ptr(mr->ram_block,
-                                   memory_region_get_ram_addr(mr) + addr1);
+            ptr = qemu_ram_ptr_length(mr->ram_block,
+                                      memory_region_get_ram_addr(mr) + addr1,
+                                      &l);
             memcpy(buf, ptr, l);
         }