From 35ddae3c3a4231d33f162c67efbcbf0cb57892ad Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Date: Tue, 23 Nov 2021 12:17:31 +0100 Subject: [PATCH 1/3] hw/scsi/lsi53c895a: Do not abort when DMA requested and no data queued MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit If asked for DMA request and no data is available, simply wait for data to be queued, do not abort. This fixes: $ cat << EOF | \ qemu-system-i386 -nographic -M q35,accel=qtest -serial none \ -monitor none -qtest stdio -trace lsi* \ -drive if=none,id=drive0,file=null-co://,file.read-zeroes=on,format=raw \ -device lsi53c895a,id=scsi0 -device scsi-hd,drive=drive0,bus=scsi0.0,channel=0,scsi-id=0,lun=0 lsi_reset Reset lsi_reg_write Write reg DSP2 0x2e = 0xff lsi_reg_write Write reg DSP3 0x2f = 0xff lsi_execute_script SCRIPTS dsp=0xffff0000 opcode 0x184a3900 arg 0x4a8b2d75 qemu-system-i386: hw/scsi/lsi53c895a.c:624: lsi_do_dma: Assertion `s->current' failed. (gdb) bt #5 0x00007ffff4e8a3a6 in __GI___assert_fail (assertion=0x5555560accbc "s->current", file=0x5555560acc28 "hw/scsi/lsi53c895a.c", line=624, function=0x5555560adb18 "lsi_do_dma") at assert.c:101 #6 0x0000555555aa33b9 in lsi_do_dma (s=0x555557805ac0, out=1) at hw/scsi/lsi53c895a.c:624 #7 0x0000555555aa5042 in lsi_execute_script (s=0x555557805ac0) at hw/scsi/lsi53c895a.c:1250 #8 0x0000555555aa757a in lsi_reg_writeb (s=0x555557805ac0, offset=47, val=255 '\377') at hw/scsi/lsi53c895a.c:1984 #9 0x0000555555aa875b in lsi_mmio_write (opaque=0x555557805ac0, addr=47, val=255, size=1) at hw/scsi/lsi53c895a.c:2095 Cc: qemu-stable@nongnu.org Cc: Gerd Hoffmann Cc: Vadim Rozenfeld Cc: Stefan Hajnoczi Reported-by: Jérôme Poulin Reported-by: Ruhr-University Reported-by: Gaoning Pan Reported-by: Cheolwoo Myung Fixes: b96a0da06bd ("lsi: move dma_len+dma_buf into lsi_request") BugLink: https://bugs.launchpad.net/qemu/+bug/697510 BugLink: https://bugs.launchpad.net/qemu/+bug/1905521 BugLink: https://bugs.launchpad.net/qemu/+bug/1908515 Resolves: https://gitlab.com/qemu-project/qemu/-/issues/84 Resolves: https://gitlab.com/qemu-project/qemu/-/issues/305 Resolves: https://gitlab.com/qemu-project/qemu/-/issues/552 Signed-off-by: Philippe Mathieu-Daudé Reviewed-by: Laurent Vivier Message-Id: <20211123111732.83137-2-philmd@redhat.com> Signed-off-by: Paolo Bonzini --- hw/scsi/lsi53c895a.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/hw/scsi/lsi53c895a.c b/hw/scsi/lsi53c895a.c index 72f7b59ab5e..7bbaefaba04 100644 --- a/hw/scsi/lsi53c895a.c +++ b/hw/scsi/lsi53c895a.c @@ -620,8 +620,7 @@ static void lsi_do_dma(LSIState *s, int out) dma_addr_t addr; SCSIDevice *dev; - assert(s->current); - if (!s->current->dma_len) { + if (!s->current || !s->current->dma_len) { /* Wait until data is available. */ trace_lsi_do_dma_unavailable(); return; -- Gitee From 5588ea3eb3d82faa4a99a7328252aa2bb406af28 Mon Sep 17 00:00:00 2001 From: Mauro Matteo Cascella Date: Tue, 5 Jul 2022 22:05:43 +0200 Subject: [PATCH 2/3] scsi/lsi53c895a: fix use-after-free in lsi_do_msgout (CVE-2022-0216) Set current_req->req to NULL to prevent reusing a free'd buffer in case of repeated SCSI cancel requests. Thanks to Thomas Huth for suggesting the patch. Fixes: CVE-2022-0216 Resolves: https://gitlab.com/qemu-project/qemu/-/issues/972 Signed-off-by: Mauro Matteo Cascella Reviewed-by: Thomas Huth Message-Id: <20220705200543.2366809-1-mcascell@redhat.com> Signed-off-by: Paolo Bonzini --- hw/scsi/lsi53c895a.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/scsi/lsi53c895a.c b/hw/scsi/lsi53c895a.c index 7bbaefaba04..16c4726dcc8 100644 --- a/hw/scsi/lsi53c895a.c +++ b/hw/scsi/lsi53c895a.c @@ -1027,8 +1027,9 @@ static void lsi_do_msgout(LSIState *s) case 0x0d: /* The ABORT TAG message clears the current I/O process only. */ trace_lsi_do_msgout_abort(current_tag); - if (current_req) { + if (current_req && current_req->req) { scsi_req_cancel(current_req->req); + current_req->req = NULL; } lsi_disconnect(s); break; -- Gitee From 13136d9656dd738b6e555cad696e4a058f8f0a2b Mon Sep 17 00:00:00 2001 From: Mauro Matteo Cascella Date: Mon, 11 Jul 2022 14:33:16 +0200 Subject: [PATCH 3/3] scsi/lsi53c895a: really fix use-after-free in lsi_do_msgout (CVE-2022-0216) Set current_req to NULL, not current_req->req, to prevent reusing a free'd buffer in case of repeated SCSI cancel requests. Also apply the fix to CLEAR QUEUE and BUS DEVICE RESET messages as well, since they also cancel the request. Thanks to Alexander Bulekov for providing a reproducer. Fixes: CVE-2022-0216 Resolves: https://gitlab.com/qemu-project/qemu/-/issues/972 Signed-off-by: Mauro Matteo Cascella Tested-by: Alexander Bulekov Message-Id: <20220711123316.421279-1-mcascell@redhat.com> Signed-off-by: Paolo Bonzini --- hw/scsi/lsi53c895a.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/scsi/lsi53c895a.c b/hw/scsi/lsi53c895a.c index 16c4726dcc8..88bccf2b4cd 100644 --- a/hw/scsi/lsi53c895a.c +++ b/hw/scsi/lsi53c895a.c @@ -1029,7 +1029,7 @@ static void lsi_do_msgout(LSIState *s) trace_lsi_do_msgout_abort(current_tag); if (current_req && current_req->req) { scsi_req_cancel(current_req->req); - current_req->req = NULL; + current_req = NULL; } lsi_disconnect(s); break; @@ -1055,6 +1055,7 @@ static void lsi_do_msgout(LSIState *s) /* clear the current I/O process */ if (s->current) { scsi_req_cancel(s->current->req); + current_req = NULL; } /* As the current implemented devices scsi_disk and scsi_generic -- Gitee