[LTP] [PATCH v3] Add a regression test for cve-2017-15649
Xiao Yang
ice_yangxiao@163.com
Thu Jan 30 10:56:57 CET 2020
On 1/30/20 5:21 PM, Michael Moese wrote:
> net/packet/af_packet.c in the Linux kernel before 4.13.6 allows local
> users to gain privileges via crafted system calls that trigger
> mishandling of packet_fanout data structures, because of a race
> condition (involving fanout_add and packet_do_bind) that leads to a
> use-after-free.
>
> See https://ssd-disclosure.com/archives/3484 for more detail.
>
> Signed-off-by: Michael Moese <mmoese@suse.de>
>
> --
> Changes to v2:
> - add tags to struct tst_test
>
> Changes to v1:
> - reworked the usage of fuzzy sync library so this should now be
> correct
> - use LTP library functions for file I/O
> - require KASAN to be enabled
> ---
> runtest/cve | 2 +-
> testcases/cve/.gitignore | 1 +
> testcases/cve/Makefile | 1 +
> testcases/cve/cve-2017-15649.c | 140 +++++++++++++++++++++++++++++++++
> 4 files changed, 143 insertions(+), 1 deletion(-)
> create mode 100644 testcases/cve/cve-2017-15649.c
>
> diff --git a/runtest/cve b/runtest/cve
> index 57cf66075..b76ddaaaa 100644
> --- a/runtest/cve
> +++ b/runtest/cve
> @@ -24,7 +24,7 @@ cve-2017-12193 add_key04
> cve-2017-15274 add_key02
> cve-2017-15299 request_key03 -b cve-2017-15299
> cve-2017-15537 ptrace07
> -cve-2017-15649 fanout01
> +cve-2017-15649 cve-2017-15649
Hi,
I wonder if fanout01 cannot trigger cve-2017-15649 reliably?
Best Regards,
Xiao Yang
> cve-2017-15951 request_key03 -b cve-2017-15951
> cve-2017-17805 af_alg02
> cve-2017-17806 af_alg01
> diff --git a/testcases/cve/.gitignore b/testcases/cve/.gitignore
> index 01a3e4c8f..08154e2db 100644
> --- a/testcases/cve/.gitignore
> +++ b/testcases/cve/.gitignore
> @@ -8,5 +8,6 @@ cve-2017-2671
> meltdown
> stack_clash
> cve-2017-17052
> +cve-2017-15649
> cve-2017-16939
> cve-2017-17053
> diff --git a/testcases/cve/Makefile b/testcases/cve/Makefile
> index da44fff60..6cf3b5af9 100644
> --- a/testcases/cve/Makefile
> +++ b/testcases/cve/Makefile
> @@ -46,5 +46,6 @@ cve-2017-17052: CFLAGS += -pthread
> cve-2017-17053: CFLAGS += -pthread
>
> cve-2015-3290: CFLAGS += -pthread
> +cve-2017-15649: CFLAGS += -pthread
>
> include $(top_srcdir)/include/mk/generic_leaf_target.mk
> diff --git a/testcases/cve/cve-2017-15649.c b/testcases/cve/cve-2017-15649.c
> new file mode 100644
> index 000000000..0bbcb6eba
> --- /dev/null
> +++ b/testcases/cve/cve-2017-15649.c
> @@ -0,0 +1,140 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright (c) 2019 Michael Moese <mmoese@suse.com>
> + */
> +/* Regression test for CVE-2017-15649
> + * based on the reproducer at https://ssd-disclosure.com/archives/3484
> + *
> + * net/packet/af_packet.c in the Linux kernel before 4.13.6 allows local users
> + * to gain privileges via crafted system calls that trigger mishandling of
> + * packet_fanout data structures, because of a race condition (involving
> + * fanout_add and packet_do_bind) that leads to a use-after-free.
> + *
> + * Be careful! This test may crash your kernel!
> + */
> +
> +#include <pthread.h>
> +#include <stdio.h>
> +#include <sched.h>
> +#include <string.h>
> +#include <time.h>
> +#include <net/if.h>
> +#include <sched.h>
> +#include <sys/types.h>
> +#include <sys/socket.h>
> +
> +#include "tst_test.h"
> +#include "tst_taint.h"
> +#include "tst_safe_pthread.h"
> +#include "tst_fuzzy_sync.h"
> +#include "tst_capability.h"
> +#include "lapi/syscalls.h"
> +
> +static struct tst_fzsync_pair fzsync_pair;
> +
> +static int fd;
> +static struct ifreq ifr;
> +
> +struct sockaddr_ll {
> + unsigned short sll_family;
> + short sll_protocol;
> + int sll_ifindex;
> + unsigned short sll_hatype;
> + unsigned char sll_pkttype;
> + unsigned char sll_halen;
> + unsigned char sll_addr[8];
> +};
> +static struct sockaddr_ll addr;
> +
> +void *bind_fn(void *unused)
> +{
> + while (tst_fzsync_run_b(&fzsync_pair)) {
> + tst_fzsync_start_race_b(&fzsync_pair);
> + bind(fd, (struct sockaddr *)&addr, sizeof(addr));
> + tst_fzsync_end_race_b(&fzsync_pair);
> + }
> + return unused;
> +}
> +
> +static void setup(void)
> +{
> + int real_uid = getuid();
> + int real_gid = getgid();
> + int index;
> +
> + tst_fzsync_pair_init(&fzsync_pair);
> + tst_taint_init(TST_TAINT_W | TST_TAINT_D | TST_TAINT_L);
> +
> + if (unshare(CLONE_NEWUSER) != 0)
> + tst_brk(TBROK | TTERRNO, "unshare(CLONE_NEWUSER) failed");
> +
> + if (unshare(CLONE_NEWNET) != 0)
> + tst_brk(TBROK | TTERRNO, "unshare(CLONE_NEWUSER) failed");
> +
> + SAFE_FILE_PRINTF("/proc/self/setgroups", "deny");
> + SAFE_FILE_PRINTF("/proc/self/uid_map", "0 %d 1\n", real_uid);
> + SAFE_FILE_PRINTF("/proc/self/gid_map", "0 %d 1\n", real_gid);
> +
> + fd = SAFE_SOCKET(AF_PACKET, SOCK_RAW, PF_PACKET);
> +
> + strcpy((char *) &ifr.ifr_name, "lo");
> + SAFE_IOCTL(fd, SIOCGIFINDEX, &ifr);
> + index = ifr.ifr_ifindex;
> +
> + SAFE_IOCTL(fd, SIOCGIFFLAGS, &ifr);
> + ifr.ifr_flags &= ~(short) IFF_UP;
> +
> + SAFE_IOCTL(fd, SIOCSIFFLAGS, &ifr);
> +
> + addr.sll_family = AF_PACKET;
> + addr.sll_protocol = 0x0;
> + addr.sll_ifindex = index;
> +}
> +
> +static void cleanup(void)
> +{
> + tst_fzsync_pair_cleanup(&fzsync_pair);
> + SAFE_CLOSE(fd);
> +}
> +
> +static void run(void)
> +{
> + int fanout = 0x3;
> +
> + tst_fzsync_pair_reset(&fzsync_pair, bind_fn);
> +
> + while (tst_fzsync_run_a(&fzsync_pair)) {
> + tst_fzsync_start_race_a(&fzsync_pair);
> + setsockopt(fd, 0x107, 18, &fanout, sizeof(fanout));
> + tst_fzsync_end_race_a(&fzsync_pair);
> + }
> +
> + tst_res(TPASS, "please check for KASAN output");
> +}
> +
> +
> +static const char *kconfigs[] = {
> + "CONFIG_KASAN",
> + "CONFIG_USER_NS",
> + NULL
> +};
> +
> +static struct tst_cap caps[] = {
> + TST_CAP(TST_CAP_REQ, CAP_SYS_ADMIN),
> + TST_CAP(TST_CAP_REQ, CAP_NET_RAW),
> + TST_CAP(TST_CAP_DROP, CAP_SYS_ADMIN),
> + {},
> +};
> +
> +static struct tst_test test = {
> + .test_all = run,
> + .setup = setup,
> + .cleanup = cleanup,
> + .needs_kconfigs = kconfigs,
> + .caps = caps,
> + .tags = (const struct tst_tag[]) {
> + {"CVE", "2017-15649"},
> + {"linux-git", "008ba2a13f2d"},
> + {}
> + }
> +};
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