| Message ID | 20210202132103.1096654-1-ppandit@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | scsi: mptsas: dequeue request object in case of an error (CVE-2021-3392) | expand |
P J P <ppandit@redhat.com> 于2021年2月2日周二 下午9:23写道： > > From: Prasad J Pandit <pjp@fedoraproject.org> > > 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 <cwmyung@snu.ac.kr> > Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org> Reviewed-by: Li Qiang <liq3ea@gmail.com> > --- > 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 f86616544b..adff5b0bf2 100644 > --- a/hw/scsi/mptsas.c > +++ b/hw/scsi/mptsas.c > @@ -257,8 +257,8 @@ 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); > } > -- > 2.29.2 > >
On 02/02/21 14:21, P J P wrote: > From: Prasad J Pandit <pjp@fedoraproject.org> > > 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 <cwmyung@snu.ac.kr> > Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org> > --- > 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 f86616544b..adff5b0bf2 100644 > --- a/hw/scsi/mptsas.c > +++ b/hw/scsi/mptsas.c > @@ -257,8 +257,8 @@ 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); > } > s->pending is not used for anything, it can just be removed. Paolo
diff --git a/hw/scsi/mptsas.c b/hw/scsi/mptsas.c index f86616544b..adff5b0bf2 100644 --- a/hw/scsi/mptsas.c +++ b/hw/scsi/mptsas.c @@ -257,8 +257,8 @@ 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); }