| Message ID | 20210419134247.1467982-1-f4bug@amsat.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [PATCH-for-6.0?,v3] mptsas: Remove unused MPTSASState 'pending' field (CVE-2021-3392) | expand |
On Mon, 19 Apr 2021 at 14:42, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote: > > From: Michael Tokarev <mjt@tls.msk.ru> > > 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> > 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> > --- > v3: Remove now unused variable in mptsas_free_request (pm215) > > MJT patch: > https://www.mail-archive.com/qemu-devel@nongnu.org/msg799236.html > > Since rc4 is soon, I'm directly respining his patch with my comments > addressed. > > This is not a new regression (present since QEMU v2.6.0) but is a > CVE... > > PJP first patch: > https://lists.gnu.org/archive/html/qemu-devel/2021-02/msg02660.html This is clearly-safe and since it's marked as a CVE and we're doing rc4 anyway we might as well put it in. Applied to master, thanks. -- PMM
On 4/19/21 6:47 PM, Peter Maydell wrote: > On Mon, 19 Apr 2021 at 14:42, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote: >> >> From: Michael Tokarev <mjt@tls.msk.ru> >> >> 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> >> 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> >> --- >> v3: Remove now unused variable in mptsas_free_request (pm215) >> >> MJT patch: >> https://www.mail-archive.com/qemu-devel@nongnu.org/msg799236.html >> >> Since rc4 is soon, I'm directly respining his patch with my comments >> addressed. >> >> This is not a new regression (present since QEMU v2.6.0) but is a >> CVE... >> >> PJP first patch: >> https://lists.gnu.org/archive/html/qemu-devel/2021-02/msg02660.html > > This is clearly-safe and since it's marked as a CVE and we're doing > rc4 anyway we might as well put it in. Applied to master, thanks. Thank you! Phil.
diff --git a/hw/scsi/mptsas.h b/hw/scsi/mptsas.h index b85ac1a5fcc..c046497db71 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); diff --git a/hw/scsi/mptsas.c b/hw/scsi/mptsas.c index 7416e787061..db3219e7d20 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); }