[LTP] [PATCH v2] Add setsockopt10 TLS ULP UAF CVE-2023-0461
Richard Palethorpe
rpalethorpe@suse.com
Mon Oct 16 11:23:46 CEST 2023
Signed-off-by: Richard Palethorpe <rpalethorpe@suse.com>
---
V2:
* rm taint check, it's done by lib
* flush before doing double free because I found it was cutting the message in two
* switch sleep to sched_yield
* also reap children before concluding we didn't trigger the bug
I haven't added needs_drivers. I'd prefer to add that later when
Petr's patchset is merged.
configure.ac | 1 +
runtest/cve | 1 +
runtest/syscalls | 1 +
.../kernel/syscalls/setsockopt/.gitignore | 1 +
.../kernel/syscalls/setsockopt/setsockopt10.c | 204 ++++++++++++++++++
5 files changed, 208 insertions(+)
create mode 100644 testcases/kernel/syscalls/setsockopt/setsockopt10.c
diff --git a/configure.ac b/configure.ac
index 30a6f56e6..e40a18fa0 100644
--- a/configure.ac
+++ b/configure.ac
@@ -64,6 +64,7 @@ AC_CHECK_HEADERS_ONCE([ \
linux/netlink.h \
linux/seccomp.h \
linux/securebits.h \
+ linux/tls.h \
linux/tty.h \
linux/types.h \
linux/userfaultfd.h \
diff --git a/runtest/cve b/runtest/cve
index f9b36a182..569558af2 100644
--- a/runtest/cve
+++ b/runtest/cve
@@ -85,6 +85,7 @@ cve-2022-0847 dirtypipe
cve-2022-2590 dirtyc0w_shmem
cve-2022-23222 bpf_prog07
cve-2023-1829 tcindex01
+cve-2023-0461 setsockopt10
# Tests below may cause kernel memory leak
cve-2020-25704 perf_event_open03
cve-2022-0185 fsconfig03
diff --git a/runtest/syscalls b/runtest/syscalls
index 53e519639..1851752cf 100644
--- a/runtest/syscalls
+++ b/runtest/syscalls
@@ -1425,6 +1425,7 @@ setsockopt06 setsockopt06
setsockopt07 setsockopt07
setsockopt08 setsockopt08
setsockopt09 setsockopt09
+setsockopt10 setsockopt10
settimeofday01 settimeofday01
settimeofday02 settimeofday02
diff --git a/testcases/kernel/syscalls/setsockopt/.gitignore b/testcases/kernel/syscalls/setsockopt/.gitignore
index fd3235bb3..5c05290a5 100644
--- a/testcases/kernel/syscalls/setsockopt/.gitignore
+++ b/testcases/kernel/syscalls/setsockopt/.gitignore
@@ -7,3 +7,4 @@
/setsockopt07
/setsockopt08
/setsockopt09
+/setsockopt10
diff --git a/testcases/kernel/syscalls/setsockopt/setsockopt10.c b/testcases/kernel/syscalls/setsockopt/setsockopt10.c
new file mode 100644
index 000000000..afd2c40a1
--- /dev/null
+++ b/testcases/kernel/syscalls/setsockopt/setsockopt10.c
@@ -0,0 +1,204 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2023 SUSE LLC Richard Palethorpe <rpalethorpe@suse.com>
+ */
+/*\
+ * [Description]
+ *
+ * Reproducer for CVE-2023-0461 which is an exploitable use-after-free
+ * in a TLS socket. In fact it is exploitable in any User Level
+ * Protocol (ULP) which does not clone its context when accepting a
+ * connection.
+ *
+ * Because it does not clone the context, the child socket which is
+ * created on accept has a pointer to the listening socket's
+ * context. When the child is closed the parent's context is freed
+ * while it still has a reference to it.
+ *
+ * TLS can only be added to a socket which is connected. Not listening
+ * or disconnected, and a connected socket can not be set to
+ * listening. So we have to connect the socket, add TLS, then
+ * disconnect, then set it to listening.
+ *
+ * To my knowledge, setting a socket from open to disconnected
+ * requires a trick; we have to "connect" to an unspecified
+ * address. This could explain why the bug was not found earlier.
+ *
+ * The accepted fix was to disallow listening on sockets with a ULP
+ * set which does not have a clone function.
+ *
+ * The test uses two processes, first the child acts as a server so
+ * that the parent can create the TLS socket. Then the child connects
+ * to the parent's TLS socket.
+ *
+ * When we try to listen on the parent, the current kernel should
+ * return EINVAL. However if clone is implemented then this could
+ * become a valid operation. It is also quite easy to crash the kernel
+ * if we set some TLS options before doing a double free.
+ *
+ * commit 2c02d41d71f90a5168391b6a5f2954112ba2307c
+ * Author: Paolo Abeni <pabeni@redhat.com>
+ * Date: Tue Jan 3 12:19:17 2023 +0100
+ *
+ * net/ulp: prevent ULP without clone op from entering the LISTEN status
+ */
+
+#include "sched.h"
+#include "tst_test.h"
+
+#ifdef HAVE_LINUX_TLS_H
+
+#include <linux/tls.h>
+#include "netinet/in.h"
+#include "netinet/tcp.h"
+
+#include "lapi/sched.h"
+#include "tst_checkpoint.h"
+#include "tst_net.h"
+#include "tst_safe_net.h"
+#include "tst_taint.h"
+
+static struct tls12_crypto_info_aes_gcm_128 opts = {
+ .info = {
+ .version = TLS_1_2_VERSION,
+ .cipher_type = TLS_CIPHER_AES_GCM_128,
+ },
+ .iv = { 'i', 'v' },
+ .key = { 'k', 'e', 'y' },
+ .salt = { 's', 'a', 'l', 't' },
+ .rec_seq = { 'r', 'e', 'c', 's' },
+};
+
+static struct sockaddr_in tcp0_addr, tcp1_addr;
+static const struct sockaddr unspec_addr = {
+ .sa_family = AF_UNSPEC
+};
+
+static int tcp0_sk, tcp1_sk, tcp2_sk, tcp3_sk;
+
+static void setup(void)
+{
+ tst_init_sockaddr_inet(&tcp0_addr, "127.0.0.1", 0x7c90);
+ tst_init_sockaddr_inet(&tcp1_addr, "127.0.0.1", 0x7c91);
+}
+
+static void cleanup(void)
+{
+ if (tcp0_sk > 0)
+ SAFE_CLOSE(tcp0_sk);
+ if (tcp1_sk > 0)
+ SAFE_CLOSE(tcp1_sk);
+ if (tcp2_sk > 0)
+ SAFE_CLOSE(tcp2_sk);
+ if (tcp3_sk > 0)
+ SAFE_CLOSE(tcp3_sk);
+}
+
+static void child(void)
+{
+ tst_res(TINFO, "child: Listen for tcp1 connection");
+ tcp0_sk = SAFE_SOCKET(AF_INET, SOCK_STREAM, 0);
+ SAFE_BIND(tcp0_sk, (struct sockaddr *)&tcp0_addr, sizeof(tcp0_addr));
+ SAFE_LISTEN(tcp0_sk, 1);
+ TST_CHECKPOINT_WAKE(0);
+
+ tcp3_sk = SAFE_ACCEPT(tcp0_sk, NULL, 0);
+ TST_CHECKPOINT_WAIT(1);
+ SAFE_CLOSE(tcp3_sk);
+ SAFE_CLOSE(tcp0_sk);
+
+ tcp3_sk = SAFE_SOCKET(AF_INET, SOCK_STREAM, 0);
+ TST_CHECKPOINT_WAIT(2);
+
+ tst_res(TINFO, "child: connect for tcp2 connection");
+ TEST(connect(tcp3_sk, (struct sockaddr *)&tcp1_addr, sizeof(tcp1_addr)));
+
+ if (TST_RET == -1) {
+ tst_res(TINFO | TTERRNO, "child: could not connect to tcp1");
+ return;
+ }
+
+ TST_CHECKPOINT_WAIT(3);
+}
+
+static void run(void)
+{
+ const pid_t child_pid = SAFE_FORK();
+
+ if (child_pid == 0) {
+ child();
+ return;
+ }
+
+ tcp1_sk = SAFE_SOCKET(AF_INET, SOCK_STREAM, 0);
+ TST_CHECKPOINT_WAIT(0);
+
+ tst_res(TINFO, "parent: Connect for tcp0 connection");
+ SAFE_CONNECT(tcp1_sk, (struct sockaddr *)&tcp0_addr, sizeof(tcp0_addr));
+ TEST(setsockopt(tcp1_sk, SOL_TCP, TCP_ULP, "tls", 3));
+
+ if (TST_RET == -1 && TST_ERR == ENOENT)
+ tst_brk(TCONF | TTERRNO, "parent: setsockopt failed: The TLS module is probably not loaded");
+ else if (TST_RET == -1)
+ tst_brk(TBROK | TTERRNO, "parent: setsockopt failed");
+
+ SAFE_SETSOCKOPT(tcp1_sk, SOL_TLS, TLS_TX, &opts, sizeof(opts));
+ TST_CHECKPOINT_WAKE(1);
+
+ tst_res(TINFO, "parent: Disconnect by setting unspec address");
+ SAFE_CONNECT(tcp1_sk, &unspec_addr, sizeof(unspec_addr));
+ SAFE_BIND(tcp1_sk, (struct sockaddr *)&tcp1_addr, sizeof(tcp1_addr));
+
+ TEST(listen(tcp1_sk, 1));
+
+ if (TST_RET == -1) {
+ if (TST_ERR == EINVAL)
+ tst_res(TPASS | TTERRNO, "parent: Can't listen on disconnected TLS socket");
+ else
+ tst_res(TCONF | TTERRNO, "parent: Can't listen on disconnected TLS socket, but the errno is not EINVAL as expected");
+
+ TST_CHECKPOINT_WAKE(2);
+ tst_reap_children();
+ return;
+ }
+
+ tst_res(TINFO, "parent: Can listen on disconnected TLS socket");
+ TST_CHECKPOINT_WAKE(2);
+
+ tcp2_sk = SAFE_ACCEPT(tcp1_sk, NULL, 0);
+ SAFE_CLOSE(tcp2_sk);
+
+ tst_res(TINFO, "parent: Attempting double free, because we set cipher options this should result in an crash");
+ tst_flush();
+ SAFE_CLOSE(tcp1_sk);
+
+ TST_CHECKPOINT_WAKE(3);
+ tst_reap_children();
+ sched_yield();
+
+ tst_res(TCONF, "parent: We're still here, maybe the kernel can clone the TLS-ULP context now?");
+}
+
+static struct tst_test test = {
+ .setup = setup,
+ .cleanup = cleanup,
+ .test_all = run,
+ .forks_child = 1,
+ .needs_checkpoints = 1,
+ .taint_check = TST_TAINT_W | TST_TAINT_D,
+ .needs_kconfigs = (const char *[]) {
+ "CONFIG_TLS",
+ NULL
+ },
+ .tags = (const struct tst_tag[]) {
+ {"linux-git", "2c02d41d71f90"},
+ {"CVE", "2023-0461"},
+ {}
+ }
+};
+
+#else
+
+TST_TEST_TCONF("linux/tls.h missing, we assume your system is too old");
+
+#endif
--
2.40.1
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