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authorPhilippe Mathieu-Daudé <philmd@redhat.com>2021-03-10 19:31:22 +0100
committerJason Wang <jasowang@redhat.com>2021-03-22 17:34:31 +0800
commit7d6a4f123e00c9dbd40867ae1a650a4fd0bc4a3d (patch)
tree7e33000caac8361374288b729abe2502daefdbc1
parentef763586c943815eb0836c54c207ce8572e176a7 (diff)
downloadqemu-arm-7d6a4f123e00c9dbd40867ae1a650a4fd0bc4a3d.tar.gz
net/eth: Read ip6_ext_hdr_routing buffer before accessing it
We can't know the caller read enough data in the memory pointed by ext_hdr to cast it as a ip6_ext_hdr_routing. Declare rt_hdr on the stack and fill it again from the iovec. Since we already checked there is enough data in the iovec buffer, simply add an assert() call to consume the bytes_read variable. This fix a 2 bytes buffer overrun in eth_parse_ipv6_hdr() reported by QEMU fuzzer: $ cat << EOF | ./qemu-system-i386 -M pc-q35-5.0 \ -accel qtest -monitor none \ -serial none -nographic -qtest stdio outl 0xcf8 0x80001010 outl 0xcfc 0xe1020000 outl 0xcf8 0x80001004 outw 0xcfc 0x7 write 0x25 0x1 0x86 write 0x26 0x1 0xdd write 0x4f 0x1 0x2b write 0xe1020030 0x4 0x190002e1 write 0xe102003a 0x2 0x0807 write 0xe1020048 0x4 0x12077cdd write 0xe1020400 0x4 0xba077cdd write 0xe1020420 0x4 0x190002e1 write 0xe1020428 0x4 0x3509d807 write 0xe1020438 0x1 0xe2 EOF ================================================================= ==2859770==ERROR: AddressSanitizer: stack-buffer-overflow on address 0x7ffdef904902 at pc 0x561ceefa78de bp 0x7ffdef904820 sp 0x7ffdef904818 READ of size 1 at 0x7ffdef904902 thread T0 #0 0x561ceefa78dd in _eth_get_rss_ex_dst_addr net/eth.c:410:17 #1 0x561ceefa41fb in eth_parse_ipv6_hdr net/eth.c:532:17 #2 0x561cef7de639 in net_tx_pkt_parse_headers hw/net/net_tx_pkt.c:228:14 #3 0x561cef7dbef4 in net_tx_pkt_parse hw/net/net_tx_pkt.c:273:9 #4 0x561ceec29f22 in e1000e_process_tx_desc hw/net/e1000e_core.c:730:29 #5 0x561ceec28eac in e1000e_start_xmit hw/net/e1000e_core.c:927:9 #6 0x561ceec1baab in e1000e_set_tdt hw/net/e1000e_core.c:2444:9 #7 0x561ceebf300e in e1000e_core_write hw/net/e1000e_core.c:3256:9 #8 0x561cef3cd4cd in e1000e_mmio_write hw/net/e1000e.c:110:5 Address 0x7ffdef904902 is located in stack of thread T0 at offset 34 in frame #0 0x561ceefa320f in eth_parse_ipv6_hdr net/eth.c:486 This frame has 1 object(s): [32, 34) 'ext_hdr' (line 487) <== Memory access at offset 34 overflows this variable HINT: this may be a false positive if your program uses some custom stack unwind mechanism, swapcontext or vfork (longjmp and C++ exceptions *are* supported) SUMMARY: AddressSanitizer: stack-buffer-overflow net/eth.c:410:17 in _eth_get_rss_ex_dst_addr Shadow bytes around the buggy address: 0x10003df188d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10003df188e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10003df188f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10003df18900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10003df18910: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 =>0x10003df18920:[02]f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 0x10003df18930: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10003df18940: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10003df18950: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10003df18960: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0x10003df18970: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Stack left redzone: f1 Stack right redzone: f3 ==2859770==ABORTING Add the corresponding qtest case with the fuzzer reproducer. FWIW GCC 11 similarly reported: net/eth.c: In function 'eth_parse_ipv6_hdr': net/eth.c:410:15: error: array subscript 'struct ip6_ext_hdr_routing[0]' is partly outside array bounds of 'struct ip6_ext_hdr[1]' [-Werror=array-bounds] 410 | if ((rthdr->rtype == 2) && (rthdr->segleft == 1)) { | ~~~~~^~~~~~~ net/eth.c:485:24: note: while referencing 'ext_hdr' 485 | struct ip6_ext_hdr ext_hdr; | ^~~~~~~ net/eth.c:410:38: error: array subscript 'struct ip6_ext_hdr_routing[0]' is partly outside array bounds of 'struct ip6_ext_hdr[1]' [-Werror=array-bounds] 410 | if ((rthdr->rtype == 2) && (rthdr->segleft == 1)) { | ~~~~~^~~~~~~~~ net/eth.c:485:24: note: while referencing 'ext_hdr' 485 | struct ip6_ext_hdr ext_hdr; | ^~~~~~~ Cc: qemu-stable@nongnu.org Buglink: https://bugs.launchpad.net/qemu/+bug/1879531 Reported-by: Alexander Bulekov <alxndr@bu.edu> Reported-by: Miroslav Rezanina <mrezanin@redhat.com> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Reviewed-by: Miroslav Rezanina <mrezanin@redhat.com> Fixes: eb700029c78 ("net_pkt: Extend packet abstraction as required by e1000e functionality") Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com> Signed-off-by: Jason Wang <jasowang@redhat.com>
-rw-r--r--MAINTAINERS1
-rw-r--r--net/eth.c13
-rw-r--r--tests/qtest/fuzz-e1000e-test.c53
-rw-r--r--tests/qtest/meson.build1
4 files changed, 63 insertions, 5 deletions
diff --git a/MAINTAINERS b/MAINTAINERS
index 25fc49d1dc..9147e9a429 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2027,6 +2027,7 @@ e1000e
M: Dmitry Fleytman <dmitry.fleytman@gmail.com>
S: Maintained
F: hw/net/e1000e*
+F: tests/qtest/fuzz-e1000e-test.c
eepro100
M: Stefan Weil <sw@weilnetz.de>
diff --git a/net/eth.c b/net/eth.c
index 6db943d4b3..b2704fbf2d 100644
--- a/net/eth.c
+++ b/net/eth.c
@@ -405,17 +405,20 @@ _eth_get_rss_ex_dst_addr(const struct iovec *pkt, int pkt_frags,
struct ip6_ext_hdr *ext_hdr,
struct in6_address *dst_addr)
{
- struct ip6_ext_hdr_routing *rthdr = (struct ip6_ext_hdr_routing *) ext_hdr;
+ struct ip6_ext_hdr_routing rt_hdr;
size_t input_size = iov_size(pkt, pkt_frags);
size_t bytes_read;
- if (input_size < ext_hdr_offset + sizeof(*rthdr) + sizeof(*dst_addr)) {
+ if (input_size < ext_hdr_offset + sizeof(rt_hdr) + sizeof(*dst_addr)) {
return false;
}
- if ((rthdr->rtype == 2) && (rthdr->segleft == 1)) {
- bytes_read = iov_to_buf(pkt, pkt_frags,
- ext_hdr_offset + sizeof(*rthdr),
+ bytes_read = iov_to_buf(pkt, pkt_frags, ext_hdr_offset,
+ &rt_hdr, sizeof(rt_hdr));
+ assert(bytes_read == sizeof(rt_hdr));
+
+ if ((rt_hdr.rtype == 2) && (rt_hdr.segleft == 1)) {
+ bytes_read = iov_to_buf(pkt, pkt_frags, ext_hdr_offset + sizeof(rt_hdr),
dst_addr, sizeof(*dst_addr));
return bytes_read == sizeof(*dst_addr);
diff --git a/tests/qtest/fuzz-e1000e-test.c b/tests/qtest/fuzz-e1000e-test.c
new file mode 100644
index 0000000000..66229e6096
--- /dev/null
+++ b/tests/qtest/fuzz-e1000e-test.c
@@ -0,0 +1,53 @@
+/*
+ * QTest testcase for e1000e device generated by fuzzer
+ *
+ * Copyright (c) 2021 Red Hat, Inc.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+
+#include "libqos/libqtest.h"
+
+/*
+ * https://bugs.launchpad.net/qemu/+bug/1879531
+ */
+static void test_lp1879531_eth_get_rss_ex_dst_addr(void)
+{
+ QTestState *s;
+
+ s = qtest_init("-nographic -monitor none -serial none -M pc-q35-5.0");
+
+ qtest_outl(s, 0xcf8, 0x80001010);
+ qtest_outl(s, 0xcfc, 0xe1020000);
+ qtest_outl(s, 0xcf8, 0x80001004);
+ qtest_outw(s, 0xcfc, 0x7);
+ qtest_writeb(s, 0x25, 0x86);
+ qtest_writeb(s, 0x26, 0xdd);
+ qtest_writeb(s, 0x4f, 0x2b);
+
+ qtest_writel(s, 0xe1020030, 0x190002e1);
+ qtest_writew(s, 0xe102003a, 0x0807);
+ qtest_writel(s, 0xe1020048, 0x12077cdd);
+ qtest_writel(s, 0xe1020400, 0xba077cdd);
+ qtest_writel(s, 0xe1020420, 0x190002e1);
+ qtest_writel(s, 0xe1020428, 0x3509d807);
+ qtest_writeb(s, 0xe1020438, 0xe2);
+ qtest_writeb(s, 0x4f, 0x2b);
+ 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/test_lp1879531_eth_get_rss_ex_dst_addr",
+ test_lp1879531_eth_get_rss_ex_dst_addr);
+ }
+
+ return g_test_run();
+}
diff --git a/tests/qtest/meson.build b/tests/qtest/meson.build
index 9731606c31..902cfef7cb 100644
--- a/tests/qtest/meson.build
+++ b/tests/qtest/meson.build
@@ -67,6 +67,7 @@ qtests_i386 = \
(config_all_devices.has_key('CONFIG_TPM_TIS_ISA') ? ['tpm-tis-test'] : []) + \
(config_all_devices.has_key('CONFIG_TPM_TIS_ISA') ? ['tpm-tis-swtpm-test'] : []) + \
(config_all_devices.has_key('CONFIG_RTL8139_PCI') ? ['rtl8139-test'] : []) + \
+ (config_all_devices.has_key('CONFIG_E1000E_PCI_EXPRESS') ? ['fuzz-e1000e-test'] : []) + \
qtests_pci + \
['fdc-test',
'ide-test',