From: Prasad J Pandit <pjp@fedoraproject.org>
Date: Wed, 12 Jul 2017 12:38:40 +0000 (+0530)
Subject: exec: use qemu_ram_ptr_length to access guest ram
X-Git-Tag: v2.9.1~5
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=15d8f91446fe922ccabb20b7e4ab4b32d8f7b5a7;p=thirdparty%2Fqemu.git

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)
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
---

diff --git a/exec.c b/exec.c
index c97ef4a8da4..72d636a4fb4 100644
--- a/exec.c
+++ b/exec.c
@@ -2765,7 +2765,7 @@ static MemTxResult address_space_write_continue(AddressSpace *as, hwaddr addr,
             }
         } else {
             /* RAM case */
-            ptr = qemu_map_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);
         }
@@ -2856,7 +2856,7 @@ MemTxResult address_space_read_continue(AddressSpace *as, hwaddr addr,
             }
         } else {
             /* RAM case */
-            ptr = qemu_map_ram_ptr(mr->ram_block, addr1);
+            ptr = qemu_ram_ptr_length(mr->ram_block, addr1, &l);
             memcpy(buf, ptr, l);
         }