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From: Paolo Bonzini <pbonzini@redhat.com>
To: qemu-devel@nongnu.org
Cc: kwolf@redhat.com
Subject: [Qemu-devel] [PATCH 1.0] qiov: prevent double free or use-after-free
Date: Fri, 25 Nov 2011 12:06:22 +0100	[thread overview]
Message-ID: <1322219182-18502-1-git-send-email-pbonzini@redhat.com> (raw)

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 <pbonzini@redhat.com>
---
 cutils.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/cutils.c b/cutils.c
index 5d995bc..731a27e 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)
-- 
1.7.7.1

             reply	other threads:[~2011-11-25 11:07 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-11-25 11:06 Paolo Bonzini [this message]
2011-11-25 11:56 ` [Qemu-devel] [PATCH 1.0] qiov: prevent double free or use-after-free Kevin Wolf
2011-11-25 11:55   ` Paolo Bonzini

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