From 24af433728429578e586d179e27451b7d4a46cba Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= <philmd@redhat.com>

Date: Thu, 18 Nov 2021 12:57:33 +0100

Subject: [PATCH 3/3] tests/qtest/fdc-test: Add a regression test for

 CVE-2021-3507

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RH-Author: Jon Maloy <jmaloy@redhat.com>

RH-MergeRequest: 194: hw/block/fdc: Prevent end-of-track overrun (CVE-2021-3507)

RH-Commit: [2/2] 31ec71276b521b06d4142fffa88a3fa4d1494d92 (jmaloy/qemu-kvm)

RH-Bugzilla: 1951521

RH-Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

RH-Acked-by: Thomas Huth <thuth@redhat.com>

RH-Acked-by: Hanna Reitz <hreitz@redhat.com>

Add the reproducer from https://gitlab.com/qemu-project/qemu/-/issues/339

Without the previous commit, when running 'make check-qtest-i386'

with QEMU configured with '--enable-sanitizers' we get:

  ==4028352==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x619000062a00 at pc 0x5626d03c491a bp 0x7ffdb4199410 sp 0x7ffdb4198bc0

  READ of size 786432 at 0x619000062a00 thread T0

      #0 0x5626d03c4919 in __asan_memcpy (qemu-system-i386+0x1e65919)

      #1 0x5626d1c023cc in flatview_write_continue softmmu/physmem.c:2787:13

      #2 0x5626d1bf0c0f in flatview_write softmmu/physmem.c:2822:14

      #3 0x5626d1bf0798 in address_space_write softmmu/physmem.c:2914:18

      #4 0x5626d1bf0f37 in address_space_rw softmmu/physmem.c:2924:16

      #5 0x5626d1bf14c8 in cpu_physical_memory_rw softmmu/physmem.c:2933:5

      #6 0x5626d0bd5649 in cpu_physical_memory_write include/exec/cpu-common.h:82:5

      #7 0x5626d0bd0a07 in i8257_dma_write_memory hw/dma/i8257.c:452:9

      #8 0x5626d09f825d in fdctrl_transfer_handler hw/block/fdc.c:1616:13

      #9 0x5626d0a048b4 in fdctrl_start_transfer hw/block/fdc.c:1539:13

      #10 0x5626d09f4c3e in fdctrl_write_data hw/block/fdc.c:2266:13

      #11 0x5626d09f22f7 in fdctrl_write hw/block/fdc.c:829:9

      #12 0x5626d1c20bc5 in portio_write softmmu/ioport.c:207:17

  0x619000062a00 is located 0 bytes to the right of 512-byte region [0x619000062800,0x619000062a00)

  allocated by thread T0 here:

      #0 0x5626d03c66ec in posix_memalign (qemu-system-i386+0x1e676ec)

      #1 0x5626d2b988d4 in qemu_try_memalign util/oslib-posix.c:210:11

      #2 0x5626d2b98b0c in qemu_memalign util/oslib-posix.c:226:27

      #3 0x5626d09fbaf0 in fdctrl_realize_common hw/block/fdc.c:2341:20

      #4 0x5626d0a150ed in isabus_fdc_realize hw/block/fdc-isa.c:113:5

      #5 0x5626d2367935 in device_set_realized hw/core/qdev.c:531:13

  SUMMARY: AddressSanitizer: heap-buffer-overflow (qemu-system-i386+0x1e65919) in __asan_memcpy

  Shadow bytes around the buggy address:

    0x0c32800044f0: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa

    0x0c3280004500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

    0x0c3280004510: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

    0x0c3280004520: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

    0x0c3280004530: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

  =>0x0c3280004540:[fa]fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa

    0x0c3280004550: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa

    0x0c3280004560: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa

    0x0c3280004570: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa

    0x0c3280004580: fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa fa

    0x0c3280004590: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd

  Shadow byte legend (one shadow byte represents 8 application bytes):

    Addressable:           00

    Heap left redzone:       fa

    Freed heap region:       fd

  ==4028352==ABORTING

[ kwolf: Added snapshot=on to prevent write file lock failure ]

Reported-by: Alexander Bulekov <alxndr@bu.edu>

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Reviewed-by: Alexander Bulekov <alxndr@bu.edu>

Signed-off-by: Kevin Wolf <kwolf@redhat.com>

(cherry picked from commit 46609b90d9e3a6304def11038a76b58ff43f77bc)

Signed-off-by: Jon Maloy <jmaloy@redhat.com>

---

 tests/qtest/fdc-test.c | 21 +++++++++++++++++++++

 1 file changed, 21 insertions(+)

diff --git a/tests/qtest/fdc-test.c b/tests/qtest/fdc-test.c

index 8f6eee84a4..6f5850354f 100644

--- a/tests/qtest/fdc-test.c

+++ b/tests/qtest/fdc-test.c

@@ -583,6 +583,26 @@ static void test_cve_2021_20196(void)

     qtest_quit(s);

 }

+static void test_cve_2021_3507(void)

+{

+    QTestState *s;

+

+    s = qtest_initf("-nographic -m 32M -nodefaults "

+                    "-drive file=%s,format=raw,if=floppy,snapshot=on",

+                    test_image);

+    qtest_outl(s, 0x9, 0x0a0206);

+    qtest_outw(s, 0x3f4, 0x1600);

+    qtest_outw(s, 0x3f4, 0x0000);

+    qtest_outw(s, 0x3f4, 0x0000);

+    qtest_outw(s, 0x3f4, 0x0000);

+    qtest_outw(s, 0x3f4, 0x0200);

+    qtest_outw(s, 0x3f4, 0x0200);

+    qtest_outw(s, 0x3f4, 0x0000);

+    qtest_outw(s, 0x3f4, 0x0000);

+    qtest_outw(s, 0x3f4, 0x0000);

+    qtest_quit(s);

+}

+

 int main(int argc, char **argv)

 {

     int fd;

@@ -614,6 +634,7 @@ int main(int argc, char **argv)

     qtest_add_func("/fdc/read_no_dma_19", test_read_no_dma_19);

     qtest_add_func("/fdc/fuzz-registers", fuzz_registers);

     qtest_add_func("/fdc/fuzz/cve_2021_20196", test_cve_2021_20196);

+    qtest_add_func("/fdc/fuzz/cve_2021_3507", test_cve_2021_3507);

     ret = g_test_run();

-- 

2.35.3