Andrew Geissler | c926e17 | 2021-05-07 16:11:35 -0500 | [diff] [blame^] | 1 | From 3791642c8d60029adf9b00bcb4e34d7d8a1aea4d Mon Sep 17 00:00:00 2001 |
| 2 | From: Michael Tokarev <mjt@tls.msk.ru> |
| 3 | Date: Mon, 19 Apr 2021 15:42:47 +0200 |
| 4 | Subject: [PATCH] mptsas: Remove unused MPTSASState 'pending' field |
| 5 | (CVE-2021-3392) |
| 6 | MIME-Version: 1.0 |
| 7 | Content-Type: text/plain; charset=UTF-8 |
| 8 | Content-Transfer-Encoding: 8bit |
| 9 | |
| 10 | While processing SCSI i/o requests in mptsas_process_scsi_io_request(), |
| 11 | the Megaraid emulator appends new MPTSASRequest object 'req' to |
| 12 | the 's->pending' queue. In case of an error, this same object gets |
| 13 | dequeued in mptsas_free_request() only if SCSIRequest object |
| 14 | 'req->sreq' is initialised. This may lead to a use-after-free issue. |
| 15 | |
| 16 | Since s->pending is actually not used, simply remove it from |
| 17 | MPTSASState. |
| 18 | |
| 19 | Cc: qemu-stable@nongnu.org |
| 20 | Signed-off-by: Michael Tokarev <mjt@tls.msk.ru> |
| 21 | Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> |
| 22 | Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> |
| 23 | Reported-by: Cheolwoo Myung <cwmyung@snu.ac.kr> |
| 24 | Message-id: 20210419134247.1467982-1-f4bug@amsat.org |
| 25 | Message-Id: <20210416102243.1293871-1-mjt@msgid.tls.msk.ru> |
| 26 | Suggested-by: Paolo Bonzini <pbonzini@redhat.com> |
| 27 | Reported-by: Cheolwoo Myung <cwmyung@snu.ac.kr> |
| 28 | BugLink: https://bugs.launchpad.net/qemu/+bug/1914236 (CVE-2021-3392) |
| 29 | Fixes: e351b826112 ("hw: Add support for LSI SAS1068 (mptsas) device") |
| 30 | [PMD: Reworded description, added more tags] |
| 31 | Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> |
| 32 | Reviewed-by: Peter Maydell <peter.maydell@linaro.org> |
| 33 | Signed-off-by: Peter Maydell <peter.maydell@linaro.org> |
| 34 | |
| 35 | CVE: CVE-2021-3392 |
| 36 | Upstream-Status: Backport [https://git.qemu.org/?p=qemu.git;a=commit;h=3791642c8d60029adf9b00bcb4e34d7d8a1aea4d] |
| 37 | Signed-off-by: Anuj Mittal <anuj.mittal@intel.com> |
| 38 | --- |
| 39 | hw/scsi/mptsas.c | 6 ------ |
| 40 | hw/scsi/mptsas.h | 1 - |
| 41 | 2 files changed, 7 deletions(-) |
| 42 | |
| 43 | diff --git a/hw/scsi/mptsas.c b/hw/scsi/mptsas.c |
| 44 | index 7416e7870614..db3219e7d206 100644 |
| 45 | --- a/hw/scsi/mptsas.c |
| 46 | +++ b/hw/scsi/mptsas.c |
| 47 | @@ -251,13 +251,10 @@ static int mptsas_build_sgl(MPTSASState *s, MPTSASRequest *req, hwaddr addr) |
| 48 | |
| 49 | static void mptsas_free_request(MPTSASRequest *req) |
| 50 | { |
| 51 | - MPTSASState *s = req->dev; |
| 52 | - |
| 53 | if (req->sreq != NULL) { |
| 54 | req->sreq->hba_private = NULL; |
| 55 | scsi_req_unref(req->sreq); |
| 56 | req->sreq = NULL; |
| 57 | - QTAILQ_REMOVE(&s->pending, req, next); |
| 58 | } |
| 59 | qemu_sglist_destroy(&req->qsg); |
| 60 | g_free(req); |
| 61 | @@ -303,7 +300,6 @@ static int mptsas_process_scsi_io_request(MPTSASState *s, |
| 62 | } |
| 63 | |
| 64 | req = g_new0(MPTSASRequest, 1); |
| 65 | - QTAILQ_INSERT_TAIL(&s->pending, req, next); |
| 66 | req->scsi_io = *scsi_io; |
| 67 | req->dev = s; |
| 68 | |
| 69 | @@ -1319,8 +1315,6 @@ static void mptsas_scsi_realize(PCIDevice *dev, Error **errp) |
| 70 | |
| 71 | s->request_bh = qemu_bh_new(mptsas_fetch_requests, s); |
| 72 | |
| 73 | - QTAILQ_INIT(&s->pending); |
| 74 | - |
| 75 | scsi_bus_new(&s->bus, sizeof(s->bus), &dev->qdev, &mptsas_scsi_info, NULL); |
| 76 | } |
| 77 | |
| 78 | diff --git a/hw/scsi/mptsas.h b/hw/scsi/mptsas.h |
| 79 | index b85ac1a5fcc7..c046497db719 100644 |
| 80 | --- a/hw/scsi/mptsas.h |
| 81 | +++ b/hw/scsi/mptsas.h |
| 82 | @@ -79,7 +79,6 @@ struct MPTSASState { |
| 83 | uint16_t reply_frame_size; |
| 84 | |
| 85 | SCSIBus bus; |
| 86 | - QTAILQ_HEAD(, MPTSASRequest) pending; |
| 87 | }; |
| 88 | |
| 89 | void mptsas_fix_scsi_io_endianness(MPIMsgSCSIIORequest *req); |