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 <[email protected]> --- 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
