From 6061f16a8a119a46e61f2ddbabdb58f83e8857f7 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 25 Nov 2011 12:06:22 +0100 Subject: [PATCH 21/25] qiov: prevent double free or use-after-free qemu_iovec_destroy does not clear the QEMUIOVector fully, and the data could thus be used after free or freed again. While I do not know any example in the tree, I observed this using virtio-scsi (and SCSI scatter/gather) when canceling DMA requests. Signed-off-by: Paolo Bonzini Signed-off-by: Kevin Wolf --- cutils.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/cutils.c b/cutils.c index 6db6304..24b3fe3 100644 --- a/cutils.c +++ b/cutils.c @@ -217,7 +217,10 @@ void qemu_iovec_destroy(QEMUIOVector *qiov) { assert(qiov->nalloc != -1); + qemu_iovec_reset(qiov); g_free(qiov->iov); + qiov->nalloc = 0; + qiov->iov = NULL; } void qemu_iovec_reset(QEMUIOVector *qiov) -- 1.7.7.5