From 27b68c47d739a3c4e5ece95ab002ee852103e11f Mon Sep 17 00:00:00 2001 From: Prasad J Pandit Date: Mon, 17 May 2021 14:24:49 +0800 Subject: [PATCH] scsi: mptsas: dequeue request object in case of an error Fix CVE-2021-3392 While processing SCSI i/o requests in mptsas_process_scsi_io_request(), the Megaraid emulator appends new MPTSASRequest object 'req' to the 's->pending' queue. In case of an error, this same object gets dequeued in mptsas_free_request() only if SCSIRequest object 'req->sreq' is initialised. This may lead to a use-after-free issue. Unconditionally dequeue 'req' object from 's->pending' to avoid it. Fixes: CVE-2021-3392 Buglink: https://bugs.launchpad.net/qemu/+bug/1914236 Reported-by: Cheolwoo Myung Signed-off-by: Prasad J Pandit Signed-off-by: Jiajie Li --- hw/scsi/mptsas.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/scsi/mptsas.c b/hw/scsi/mptsas.c index 3f94d5ab55..4d23f045d7 100644 --- a/hw/scsi/mptsas.c +++ b/hw/scsi/mptsas.c @@ -259,8 +259,8 @@ static void mptsas_free_request(MPTSASRequest *req) req->sreq->hba_private = NULL; scsi_req_unref(req->sreq); req->sreq = NULL; - QTAILQ_REMOVE(&s->pending, req, next); } + QTAILQ_REMOVE(&s->pending, req, next); qemu_sglist_destroy(&req->qsg); g_free(req); } -- 2.27.0