File mptsas-Remove-unused-MPTSASState-pending.patch of Package qemu.20097
From: Michael Tokarev <mjt@tls.msk.ru>
Date: Mon, 19 Apr 2021 15:42:47 +0200
Subject: mptsas: Remove unused MPTSASState 'pending' field (CVE-2021-3392)
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Git-commit: 3791642c8d60029adf9b00bcb4e34d7d8a1aea4d
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.
Since s->pending is actually not used, simply remove it from
MPTSASState.
Cc: qemu-stable@nongnu.org
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reported-by: Cheolwoo Myung <cwmyung@snu.ac.kr>
Message-id: 20210419134247.1467982-1-f4bug@amsat.org
Message-Id: <20210416102243.1293871-1-mjt@msgid.tls.msk.ru>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Reported-by: Cheolwoo Myung <cwmyung@snu.ac.kr>
BugLink: https://bugs.launchpad.net/qemu/+bug/1914236 (CVE-2021-3392)
Fixes: e351b826112 ("hw: Add support for LSI SAS1068 (mptsas) device")
[PMD: Reworded description, added more tags]
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
hw/scsi/mptsas.c | 6 ------
hw/scsi/mptsas.h | 1 -
2 files changed, 7 deletions(-)
diff --git a/hw/scsi/mptsas.c b/hw/scsi/mptsas.c
index f86616544bacf71da60270ad06ed..12c957e06be41e80963bcabae1f8 100644
--- a/hw/scsi/mptsas.c
+++ b/hw/scsi/mptsas.c
@@ -251,13 +251,10 @@ static int mptsas_build_sgl(MPTSASState *s, MPTSASRequest *req, hwaddr addr)
static void mptsas_free_request(MPTSASRequest *req)
{
- MPTSASState *s = req->dev;
-
if (req->sreq != NULL) {
req->sreq->hba_private = NULL;
scsi_req_unref(req->sreq);
req->sreq = NULL;
- QTAILQ_REMOVE(&s->pending, req, next);
}
qemu_sglist_destroy(&req->qsg);
g_free(req);
@@ -303,7 +300,6 @@ static int mptsas_process_scsi_io_request(MPTSASState *s,
}
req = g_new0(MPTSASRequest, 1);
- QTAILQ_INSERT_TAIL(&s->pending, req, next);
req->scsi_io = *scsi_io;
req->dev = s;
@@ -1318,8 +1314,6 @@ static void mptsas_scsi_realize(PCIDevice *dev, Error **errp)
s->request_bh = qemu_bh_new(mptsas_fetch_requests, s);
- QTAILQ_INIT(&s->pending);
-
scsi_bus_new(&s->bus, sizeof(s->bus), &dev->qdev, &mptsas_scsi_info, NULL);
}
diff --git a/hw/scsi/mptsas.h b/hw/scsi/mptsas.h
index b85ac1a5fcc7ad3ffc72923c734c..c046497db71989a564ed46481036 100644
--- a/hw/scsi/mptsas.h
+++ b/hw/scsi/mptsas.h
@@ -79,7 +79,6 @@ struct MPTSASState {
uint16_t reply_frame_size;
SCSIBus bus;
- QTAILQ_HEAD(, MPTSASRequest) pending;
};
void mptsas_fix_scsi_io_endianness(MPIMsgSCSIIORequest *req);