qemu-kvm/SOURCES/kvm-exec-check-that-alignment-is-a-power-of-two.patch

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From f5eecfb16d182d3c37df06bf20e6843f126b33fe Mon Sep 17 00:00:00 2001
From: David Hildenbrand <david@redhat.com>
Date: Fri, 21 Sep 2018 10:18:00 +0100
Subject: [PATCH 3/4] exec: check that alignment is a power of two
RH-Author: David Hildenbrand <david@redhat.com>
Message-id: <20180921101800.27360-1-david@redhat.com>
Patchwork-id: 82229
O-Subject: [RHEL-8.0 qemu-kvm PATCH] exec: check that alignment is a power of two
Bugzilla: 1630746
RH-Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
RH-Acked-by: Pankaj Gupta <pagupta@redhat.com>
RH-Acked-by: Igor Mammedov <imammedo@redhat.com>
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
BZ: https://bugzilla.redhat.com/show_bug.cgi?id=1630746
Brew: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=18439951
Branch: rhel8/master-2.12.0
Upstream: 61362b71c105ccb151ca16897a7d56534423f390
Right now we can crash QEMU using e.g.
qemu-system-x86_64 -m 256M,maxmem=20G,slots=2 \
-object memory-backend-file,id=mem0,size=12288,mem-path=/dev/zero,align=12288 \
-device pc-dimm,id=dimm1,memdev=mem0
qemu-system-x86_64: util/mmap-alloc.c:115:
qemu_ram_mmap: Assertion `is_power_of_2(align)' failed
Fix this by adding a proper check.
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180607154705.6316-3-david@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
(cherry picked from commit 61362b71c105ccb151ca16897a7d56534423f390)
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
---
exec.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/exec.c b/exec.c
index 02b1efe..22cc7ef 100644
--- a/exec.c
+++ b/exec.c
@@ -1646,6 +1646,10 @@ static void *file_ram_alloc(RAMBlock *block,
" must be multiples of page size 0x%zx",
block->mr->align, block->page_size);
return NULL;
+ } else if (block->mr->align && !is_power_of_2(block->mr->align)) {
+ error_setg(errp, "alignment 0x%" PRIx64
+ " must be a power of two", block->mr->align);
+ return NULL;
}
block->mr->align = MAX(block->page_size, block->mr->align);
#if defined(__s390x__)
--
1.8.3.1