From 3791642c8d60029adf9b00bcb4e34d7d8a1aea4d Mon Sep 17 00:00:00 2001 From: Michael Tokarev Date: Mon, 19 Apr 2021 15:42:47 +0200 Subject: [PATCH] mptsas: Remove unused MPTSASState 'pending' field (CVE-2021-3392) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Philippe Mathieu-Daudé Reported-by: Cheolwoo Myung Message-id: 20210419134247.1467982-1-f4bug@amsat.org Message-Id: <20210416102243.1293871-1-mjt@msgid.tls.msk.ru> Suggested-by: Paolo Bonzini Reported-by: Cheolwoo Myung 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 Reviewed-by: Peter Maydell Signed-off-by: Peter Maydell CVE: CVE-2021-3392 Upstream-Status: Backport [https://git.qemu.org/?p=qemu.git;a=commit;h=3791642c8d60029adf9b00bcb4e34d7d8a1aea4d] Signed-off-by: Anuj Mittal --- 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 7416e7870614..db3219e7d206 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; @@ -1319,8 +1315,6 @@ 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 b85ac1a5fcc7..c046497db719 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);