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[Qemu-devel] [PATCH v1 2/2] exec: check that alignment is a power of two
From: |
David Hildenbrand |
Subject: |
[Qemu-devel] [PATCH v1 2/2] exec: check that alignment is a power of two |
Date: |
Thu, 7 Jun 2018 17:47:05 +0200 |
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 <address@hidden>
---
exec.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/exec.c b/exec.c
index f6645ede0c..f54c83ac61 100644
--- a/exec.c
+++ b/exec.c
@@ -1681,6 +1681,10 @@ 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__)
--
2.17.0