Assertion `tx_queue_idx <= s->txq_num' failed in vmxnet3_io_bar0_write

[Alexander Bulekov]

=== Stacktrace ===

qemu-fuzz-i386: ../hw/net/vmxnet3.c:1096: void vmxnet3_io_bar0_write(void *, hwaddr, uint64_t, unsigned int): Assertion `tx_queue_idx <= s->txq_num' failed.
==602353== ERROR: libFuzzer: deadly signal
#5 0x7fe4b93a7ce0 in raise signal/../sysdeps/unix/sysv/linux/raise.c:48:3
#6 0x7fe4b9391536 in abort stdlib/abort.c:79:7
#7 0x7fe4b939140e in __assert_fail_base assert/assert.c:92:3
#8 0x7fe4b93a0661 in __assert_fail assert/assert.c:101:3
#9 0x563e6cf5ebb5 in vmxnet3_io_bar0_write hw/net/vmxnet3.c:1096:9
#10 0x563e6eefdb00 in memory_region_write_accessor softmmu/memory.c:491:5
#11 0x563e6eefcfdd in access_with_adjusted_size softmmu/memory.c:552:18
#12 0x563e6eefac90 in memory_region_dispatch_write softmmu/memory.c:1502:16
#13 0x563e6e834e16 in flatview_write_continue softmmu/physmem.c:2746:23
#14 0x563e6e81cd38 in flatview_write softmmu/physmem.c:2786:14
#15 0x563e6e81c868 in address_space_write softmmu/physmem.c:2878:18

=== Reproducer ===
cat << EOF | ./qemu-system-i386 -display none -machine accel=qtest, -m \
512M -machine q35 -nodefaults -device vmxnet3,netdev=net0 -netdev \
user,id=net0 -qtest stdio
outl 0xcf8 0x80000810
outl 0xcfc 0xe0000000
outl 0xcf8 0x80000814
outl 0xcf8 0x80000804
outw 0xcfc 0x7
outl 0xcf8 0x80000815
outl 0xcfc 0xffff00b5
write 0x0 0x1 0xe1
write 0x1 0x1 0xfe
write 0x2 0x1 0xbe
write 0x3 0x1 0xba
write 0xff00b020 0x4 0x0000feca
write 0xe0000630 0x1 0x00
EOF

=== Testcase ===

/*
 * Autogenerated Fuzzer Test Case
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 */

#include "qemu/osdep.h"

#include "libqos/libqtest.h"

static void test_fuzz(void) {
    QTestState *s = qtest_init(" -display none , -m 512M -machine q35 -nodefaults "
                               "-device vmxnet3,netdev=net0 -netdev user,id=net0");
    qtest_outl(s, 0xcf8, 0x80000810);
    qtest_outl(s, 0xcfc, 0xe0000000);
    qtest_outl(s, 0xcf8, 0x80000814);
    qtest_outl(s, 0xcf8, 0x80000804);
    qtest_outw(s, 0xcfc, 0x7);
    qtest_outl(s, 0xcf8, 0x80000815);
    qtest_outl(s, 0xcfc, 0xffff00b5);
    qtest_bufwrite(s, 0x0, "\xe1", 0x1);
    qtest_bufwrite(s, 0x1, "\xfe", 0x1);
    qtest_bufwrite(s, 0x2, "\xbe", 0x1);
    qtest_bufwrite(s, 0x3, "\xba", 0x1);
    qtest_bufwrite(s, 0xff00b020, "\x00\x00\xfe\xca", 0x4);
    qtest_bufwrite(s, 0xe0000630, "\x00", 0x1);
    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) {
        qtest_add_func("fuzz/test_fuzz", test_fuzz);
    }

    return g_test_run();
}

=== OSS-Fuzz Report ===
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=33603
https://oss-fuzz.com/testcase?key=6071483232288768

[Philippe Mathieu-Daudé (philmd)]

Cc'ing maintainers.

./scripts/get_maintainer.pl -f hw/net/vmxnet3.c
Dmitry Fleytman <email address hidden> (maintainer:Vmware)
Jason Wang <email address hidden> (odd fixer:Network devices)

On 4/26/21 5:19 AM, Alexander Bulekov wrote:
> Public bug reported:
>
> === Stacktrace ===
>
> qemu-fuzz-i386: ../hw/net/vmxnet3.c:1096: void vmxnet3_io_bar0_write(void *, hwaddr, uint64_t, unsigned int): Assertion `tx_queue_idx <= s->txq_num' failed.
> ==602353== ERROR: libFuzzer: deadly signal
> #5 0x7fe4b93a7ce0 in raise signal/../sysdeps/unix/sysv/linux/raise.c:48:3
> #6 0x7fe4b9391536 in abort stdlib/abort.c:79:7
> #7 0x7fe4b939140e in __assert_fail_base assert/assert.c:92:3
> #8 0x7fe4b93a0661 in __assert_fail assert/assert.c:101:3
> #9 0x563e6cf5ebb5 in vmxnet3_io_bar0_write hw/net/vmxnet3.c:1096:9
> #10 0x563e6eefdb00 in memory_region_write_accessor softmmu/memory.c:491:5
> #11 0x563e6eefcfdd in access_with_adjusted_size softmmu/memory.c:552:18
> #12 0x563e6eefac90 in memory_region_dispatch_write softmmu/memory.c:1502:16
> #13 0x563e6e834e16 in flatview_write_continue softmmu/physmem.c:2746:23
> #14 0x563e6e81cd38 in flatview_write softmmu/physmem.c:2786:14
> #15 0x563e6e81c868 in address_space_write softmmu/physmem.c:2878:18
>
> === Reproducer ===
> cat << EOF | ./qemu-system-i386 -display none -machine accel=qtest, -m \
> 512M -machine q35 -nodefaults -device vmxnet3,netdev=net0 -netdev \
> user,id=net0 -qtest stdio
> outl 0xcf8 0x80000810
> outl 0xcfc 0xe0000000
> outl 0xcf8 0x80000814
> outl 0xcf8 0x80000804
> outw 0xcfc 0x7
> outl 0xcf8 0x80000815
> outl 0xcfc 0xffff00b5
> write 0x0 0x1 0xe1
> write 0x1 0x1 0xfe
> write 0x2 0x1 0xbe
> write 0x3 0x1 0xba
> write 0xff00b020 0x4 0x0000feca
> write 0xe0000630 0x1 0x00
> EOF
>
>
> === Testcase ===
>
> /*
> * Autogenerated Fuzzer Test Case
> *
> * This work is licensed under the terms of the GNU GPL, version 2 or later.
> * See the COPYING file in the top-level directory.
> */
>
> #include "qemu/osdep.h"
>
> #include "libqos/libqtest.h"
>
> static void test_fuzz(void) {
> QTestState *s = qtest_init(" -display none , -m 512M -machine q35 -nodefaults "
> "-device vmxnet3,netdev=net0 -netdev user,id=net0");
> qtest_outl(s, 0xcf8, 0x80000810);
> qtest_outl(s, 0xcfc, 0xe0000000);
> qtest_outl(s, 0xcf8, 0x80000814);
> qtest_outl(s, 0xcf8, 0x80000804);
> qtest_outw(s, 0xcfc, 0x7);
> qtest_outl(s, 0xcf8, 0x80000815);
> qtest_outl(s, 0xcfc, 0xffff00b5);
> qtest_bufwrite(s, 0x0, "\xe1", 0x1);
> qtest_bufwrite(s, 0x1, "\xfe", 0x1);
> qtest_bufwrite(s, 0x2, "\xbe", 0x1);
> qtest_bufwrite(s, 0x3, "\xba", 0x1);
> qtest_bufwrite(s, 0xff00b020, "\x00\x00\xfe\xca", 0x4);
> qtest_bufwrite(s, 0xe0000630, "\x00", 0x1);
> 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) {
> qtest_add_func("fuzz/test_fuzz", test_fuzz);
> }
>
> return g_test_run();
> }
>
>
> === OSS-Fuzz Report ===
> https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=33603
> https://oss-fu...

[Thomas Huth (th-huth)]

I can reproduce this issue with the latest version of QEMU. Marking as "Confirmed"

[Thomas Huth (th-huth)]

Suggested fix: https://<email address hidden>/

[Thomas Huth (th-huth)]

Fix has been included here:
https://gitlab.com/qemu-project/qemu/-/commit/6a932c4ed8748b08c58c