[PATCH-for-6.2 0/2] hw/scsi/lsi53c895a: Fix guest-triggerable assert() in lsi_do_dma()

[PATCH-for-6.2 0/2] hw/scsi/lsi53c895a: Fix guest-triggerable assert() in lsi_do_dma()

[Philippe Mathieu-Daudé]

Trivial fix for this long due bug.

Philippe Mathieu-Daudé (2):
  hw/scsi/lsi53c895a: Do not abort when DMA requested and no data queued
  tests/qtest: Add fuzz-lsi53c895a-test

 hw/scsi/lsi53c895a.c               |  3 +-
 tests/qtest/fuzz-lsi53c895a-test.c | 52 ++++++++++++++++++++++++++++++
 MAINTAINERS                        |  1 +
 tests/qtest/meson.build            |  1 +
 4 files changed, 55 insertions(+), 2 deletions(-)
 create mode 100644 tests/qtest/fuzz-lsi53c895a-test.c

-- 
2.33.1

[PATCH-for-6.2 1/2] hw/scsi/lsi53c895a: Do not abort when DMA requested and no data queued

[Philippe Mathieu-Daudé]

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 <kraxel@redhat.com>
Cc: Vadim Rozenfeld <vrozenfe@redhat.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Reported-by: Jérôme Poulin <jeromepoulin@gmail.com>
Reported-by: Ruhr-University <bugs-syssec@rub.de>
Reported-by: Gaoning Pan <pgn@zju.edu.cn>
Reported-by: Cheolwoo Myung <cwmyung@snu.ac.kr>
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 <philmd@redhat.com>
---
 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 85e907a7854..4c431adb774 100644
--- a/hw/scsi/lsi53c895a.c
+++ b/hw/scsi/lsi53c895a.c
@@ -621,8 +621,7 @@ 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;
-- 
2.33.1

[PATCH-for-6.2 2/2] tests/qtest: Add fuzz-lsi53c895a-test

[Philippe Mathieu-Daudé]

Without the previous commit, this test triggers:

  $ make check-qtest-x86_64
  [...]
  Running test qtest-x86_64/fuzz-lsi53c895a-test
  qemu-system-x86_64: hw/scsi/lsi53c895a.c:624: lsi_do_dma: Assertion `s->current' failed.
  ERROR qtest-x86_64/fuzz-lsi53c895a-test - too few tests run (expected 1, got 0)

Suggested-by: Alexander Bulekov <alxndr@bu.edu>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 tests/qtest/fuzz-lsi53c895a-test.c | 52 ++++++++++++++++++++++++++++++
 MAINTAINERS                        |  1 +
 tests/qtest/meson.build            |  1 +
 3 files changed, 54 insertions(+)
 create mode 100644 tests/qtest/fuzz-lsi53c895a-test.c

diff --git a/tests/qtest/fuzz-lsi53c895a-test.c b/tests/qtest/fuzz-lsi53c895a-test.c
new file mode 100644
index 00000000000..ba5d468970c
--- /dev/null
+++ b/tests/qtest/fuzz-lsi53c895a-test.c
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * QTest fuzzer-generated testcase for LSI53C895A device
+ *
+ * Copyright (c) Red Hat
+ */
+
+#include "qemu/osdep.h"
+#include "libqos/libqtest.h"
+
+/*
+ * This used to trigger the assert in lsi_do_dma()
+ * https://bugs.launchpad.net/qemu/+bug/697510
+ * https://bugs.launchpad.net/qemu/+bug/1905521
+ * https://bugs.launchpad.net/qemu/+bug/1908515
+ */
+static void test_lsi_do_dma_empty_queue(void)
+{
+    QTestState *s;
+
+    s = qtest_init("-M q35 -nographic -monitor none -serial none "
+                   "-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");
+    qtest_outl(s, 0xcf8, 0x80001814);
+    qtest_outl(s, 0xcfc, 0xe1068000);
+    qtest_outl(s, 0xcf8, 0x80001818);
+    qtest_outl(s, 0xcf8, 0x80001804);
+    qtest_outw(s, 0xcfc, 0x7);
+    qtest_outl(s, 0xcf8, 0x80002010);
+
+    qtest_writeb(s, 0xe106802e, 0xff); /* Fill DSP bits 16-23 */
+    qtest_writeb(s, 0xe106802f, 0xff); /* Fill DSP bits 24-31: trigger SCRIPT */
+
+    qtest_quit(s);
+}
+
+int main(int argc, char **argv)
+{
+    const char *arch = qtest_get_arch();
+
+    g_test_init(&argc, &argv, NULL);
+
+    if (strcmp(arch, "i386") == 0 || strcmp(arch, "x86_64") == 0) {
+        qtest_add_func("fuzz/lsi53c895a/lsi_do_dma_empty_queue",
+                       test_lsi_do_dma_empty_queue);
+    }
+
+    return g_test_run();
+}
diff --git a/MAINTAINERS b/MAINTAINERS
index d3879aa3c12..3c0f76b7801 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1825,6 +1825,7 @@ F: hw/scsi/*
 F: tests/qtest/virtio-scsi-test.c
 F: tests/qtest/fuzz-virtio-scsi-test.c
 F: tests/qtest/am53c974-test.c
+F: tests/qtest/fuzz-lsi53c895a-test.c
 T: git https://github.com/bonzini/qemu.git scsi-next
 
 SSI
diff --git a/tests/qtest/meson.build b/tests/qtest/meson.build
index c9d8458062f..d2ce20d3047 100644
--- a/tests/qtest/meson.build
+++ b/tests/qtest/meson.build
@@ -19,6 +19,7 @@
 
 qtests_generic = \
   (config_all_devices.has_key('CONFIG_MEGASAS_SCSI_PCI') ? ['fuzz-megasas-test'] : []) + \
+  (config_all_devices.has_key('CONFIG_LSI_SCSI_PCI') ? ['fuzz-lsi53c895a-test'] : []) + \
   (config_all_devices.has_key('CONFIG_VIRTIO_SCSI') ? ['fuzz-virtio-scsi-test'] : []) + \
   (config_all_devices.has_key('CONFIG_SB16') ? ['fuzz-sb16-test'] : []) + \
   (config_all_devices.has_key('CONFIG_SDHCI_PCI') ? ['fuzz-sdcard-test'] : []) + \
-- 
2.33.1

Re: [PATCH-for-6.2 1/2] hw/scsi/lsi53c895a: Do not abort when DMA requested and no data queued

[Laurent Vivier]

On 23/11/2021 12:17, Philippe Mathieu-Daudé wrote:
> 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 <kraxel@redhat.com>
> Cc: Vadim Rozenfeld <vrozenfe@redhat.com>
> Cc: Stefan Hajnoczi <stefanha@redhat.com>
> Reported-by: Jérôme Poulin <jeromepoulin@gmail.com>
> Reported-by: Ruhr-University <bugs-syssec@rub.de>
> Reported-by: Gaoning Pan <pgn@zju.edu.cn>
> Reported-by: Cheolwoo Myung <cwmyung@snu.ac.kr>
> 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 <philmd@redhat.com>
> ---
>   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 85e907a7854..4c431adb774 100644
> --- a/hw/scsi/lsi53c895a.c
> +++ b/hw/scsi/lsi53c895a.c
> @@ -621,8 +621,7 @@ 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;
> 

Reviewed-by: Laurent Vivier <lvivier@redhat.com>

Re: [PATCH-for-6.2 2/2] tests/qtest: Add fuzz-lsi53c895a-test

[Laurent Vivier]

On 23/11/2021 12:17, Philippe Mathieu-Daudé wrote:
> Without the previous commit, this test triggers:
> 
>    $ make check-qtest-x86_64
>    [...]
>    Running test qtest-x86_64/fuzz-lsi53c895a-test
>    qemu-system-x86_64: hw/scsi/lsi53c895a.c:624: lsi_do_dma: Assertion `s->current' failed.
>    ERROR qtest-x86_64/fuzz-lsi53c895a-test - too few tests run (expected 1, got 0)
> 
> Suggested-by: Alexander Bulekov <alxndr@bu.edu>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>   tests/qtest/fuzz-lsi53c895a-test.c | 52 ++++++++++++++++++++++++++++++
>   MAINTAINERS                        |  1 +
>   tests/qtest/meson.build            |  1 +
>   3 files changed, 54 insertions(+)
>   create mode 100644 tests/qtest/fuzz-lsi53c895a-test.c
> 
> diff --git a/tests/qtest/fuzz-lsi53c895a-test.c b/tests/qtest/fuzz-lsi53c895a-test.c
> new file mode 100644
> index 00000000000..ba5d468970c
> --- /dev/null
> +++ b/tests/qtest/fuzz-lsi53c895a-test.c
> @@ -0,0 +1,52 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * QTest fuzzer-generated testcase for LSI53C895A device
> + *
> + * Copyright (c) Red Hat
> + */
> +
> +#include "qemu/osdep.h"
> +#include "libqos/libqtest.h"
> +
> +/*
> + * This used to trigger the assert in lsi_do_dma()
> + * https://bugs.launchpad.net/qemu/+bug/697510
> + * https://bugs.launchpad.net/qemu/+bug/1905521
> + * https://bugs.launchpad.net/qemu/+bug/1908515
> + */
> +static void test_lsi_do_dma_empty_queue(void)
> +{
> +    QTestState *s;
> +
> +    s = qtest_init("-M q35 -nographic -monitor none -serial none "
> +                   "-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");
> +    qtest_outl(s, 0xcf8, 0x80001814);
> +    qtest_outl(s, 0xcfc, 0xe1068000);
> +    qtest_outl(s, 0xcf8, 0x80001818);
> +    qtest_outl(s, 0xcf8, 0x80001804);
> +    qtest_outw(s, 0xcfc, 0x7);
> +    qtest_outl(s, 0xcf8, 0x80002010);
> +
> +    qtest_writeb(s, 0xe106802e, 0xff); /* Fill DSP bits 16-23 */
> +    qtest_writeb(s, 0xe106802f, 0xff); /* Fill DSP bits 24-31: trigger SCRIPT */
> +
> +    qtest_quit(s);
> +}
> +
> +int main(int argc, char **argv)
> +{
> +    const char *arch = qtest_get_arch();
> +
> +    g_test_init(&argc, &argv, NULL);
> +
> +    if (strcmp(arch, "i386") == 0 || strcmp(arch, "x86_64") == 0) {
> +        qtest_add_func("fuzz/lsi53c895a/lsi_do_dma_empty_queue",
> +                       test_lsi_do_dma_empty_queue);
> +    }
> +
> +    return g_test_run();
> +}
> diff --git a/MAINTAINERS b/MAINTAINERS
> index d3879aa3c12..3c0f76b7801 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -1825,6 +1825,7 @@ F: hw/scsi/*
>   F: tests/qtest/virtio-scsi-test.c
>   F: tests/qtest/fuzz-virtio-scsi-test.c
>   F: tests/qtest/am53c974-test.c
> +F: tests/qtest/fuzz-lsi53c895a-test.c
>   T: git https://github.com/bonzini/qemu.git scsi-next
>   
>   SSI
> diff --git a/tests/qtest/meson.build b/tests/qtest/meson.build
> index c9d8458062f..d2ce20d3047 100644
> --- a/tests/qtest/meson.build
> +++ b/tests/qtest/meson.build
> @@ -19,6 +19,7 @@
>   
>   qtests_generic = \
>     (config_all_devices.has_key('CONFIG_MEGASAS_SCSI_PCI') ? ['fuzz-megasas-test'] : []) + \
> +  (config_all_devices.has_key('CONFIG_LSI_SCSI_PCI') ? ['fuzz-lsi53c895a-test'] : []) + \
>     (config_all_devices.has_key('CONFIG_VIRTIO_SCSI') ? ['fuzz-virtio-scsi-test'] : []) + \
>     (config_all_devices.has_key('CONFIG_SB16') ? ['fuzz-sb16-test'] : []) + \
>     (config_all_devices.has_key('CONFIG_SDHCI_PCI') ? ['fuzz-sdcard-test'] : []) + \
> 

Reviewed-by: Laurent Vivier <lvivier@redhat.com>

Re: [PATCH-for-6.2 0/2] hw/scsi/lsi53c895a: Fix guest-triggerable assert() in lsi_do_dma()

[Paolo Bonzini]

On 11/23/21 12:17, Philippe Mathieu-Daudé wrote:
> Trivial fix for this long due bug.
> 
> Philippe Mathieu-Daudé (2):
>    hw/scsi/lsi53c895a: Do not abort when DMA requested and no data queued
>    tests/qtest: Add fuzz-lsi53c895a-test
> 
>   hw/scsi/lsi53c895a.c               |  3 +-
>   tests/qtest/fuzz-lsi53c895a-test.c | 52 ++++++++++++++++++++++++++++++
>   MAINTAINERS                        |  1 +
>   tests/qtest/meson.build            |  1 +
>   4 files changed, 55 insertions(+), 2 deletions(-)
>   create mode 100644 tests/qtest/fuzz-lsi53c895a-test.c
> 

Queued, thanks.

Paolo