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- nsswitch: add test for pthread_key_delete missuse (bug 15464)

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eabdullin 2024-02-21 13:14:12 +03:00
parent 04e2eb07a7
commit 3caafdd88f
2 changed files with 620 additions and 1 deletions
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613
SOURCES/memory-corruption-since-samba-4-18.patch Normal file
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@ -0,0 +1,613 @@
From ced40c5a805dcfb06d5f3d68aa45a0aaa44bfdca Mon Sep 17 00:00:00 2001
From: Stefan Metzmacher <metze@samba.org>
Date: Fri, 8 Sep 2023 13:57:26 +0200
Subject: [PATCH 1/5] nsswitch: add test for pthread_key_delete missuse (bug
15464)
This is based on https://bugzilla.samba.org/attachment.cgi?id=18081
written by Krzysztof Piotr Oledzki <ole@ans.pl>
BUG: https://bugzilla.samba.org/show_bug.cgi?id=15464
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
(cherry picked from commit 62af25d44e542548d8cdecb061a6001e0071ee76)
---
nsswitch/b15464-testcase.c | 77 +++++++++++++++++++++++++++
nsswitch/wscript_build | 5 ++
selftest/knownfail.d/b15464_testcase | 1 +
source3/selftest/tests.py | 6 +++
testprogs/blackbox/b15464-testcase.sh | 21 ++++++++
5 files changed, 110 insertions(+)
create mode 100644 nsswitch/b15464-testcase.c
create mode 100644 selftest/knownfail.d/b15464_testcase
create mode 100755 testprogs/blackbox/b15464-testcase.sh
diff --git a/nsswitch/b15464-testcase.c b/nsswitch/b15464-testcase.c
new file mode 100644
index 000000000000..decb474a81ee
--- /dev/null
+++ b/nsswitch/b15464-testcase.c
@@ -0,0 +1,77 @@
+#include "replace.h"
+#include "system/wait.h"
+#include "system/threads.h"
+#include <assert.h>
+
+int main(int argc, const char *argv[])
+{
+ pid_t pid;
+ int wstatus;
+ pthread_key_t k1;
+ pthread_key_t k2;
+ pthread_key_t k3;
+ char *val = NULL;
+ const char *nss_winbind = (argc >= 2 ? argv[1] : "bin/plugins/libnss_winbind.so.2");
+ void *nss_winbind_handle = NULL;
+ union {
+ int (*fn)(void);
+ void *symbol;
+ } nss_winbind_endpwent = { .symbol = NULL, };
+
+ /*
+ * load and invoke something simple like
+ * _nss_winbind_endpwent in order to
+ * get the libnss_winbind internal going
+ */
+ nss_winbind_handle = dlopen(nss_winbind, RTLD_NOW);
+ printf("%d: nss_winbind[%s] nss_winbind_handle[%p]\n",
+ getpid(), nss_winbind, nss_winbind_handle);
+ assert(nss_winbind_handle != NULL);
+
+ nss_winbind_endpwent.symbol = dlsym(nss_winbind_handle,
+ "_nss_winbind_endpwent");
+ printf("%d: nss_winbind_handle[%p] _nss_winbind_endpwent[%p]\n",
+ getpid(), nss_winbind_handle, nss_winbind_endpwent.symbol);
+ assert(nss_winbind_endpwent.symbol != NULL);
+ (void)nss_winbind_endpwent.fn();
+
+ val = malloc(1);
+ assert(val != NULL);
+
+ pthread_key_create(&k1, NULL);
+ pthread_setspecific(k1, val);
+ printf("%d: k1=%d\n", getpid(), k1);
+
+ pid = fork();
+ if (pid) {
+ free(val);
+ wait(&wstatus);
+ return WEXITSTATUS(wstatus);
+ }
+
+ pthread_key_create(&k2, NULL);
+ pthread_setspecific(k2, val);
+
+ printf("%d: Hello after fork, k1=%d, k2=%d\n", getpid(), k1, k2);
+
+ pid = fork();
+
+ if (pid) {
+ free(val);
+ wait(&wstatus);
+ return WEXITSTATUS(wstatus);
+ }
+
+ pthread_key_create(&k3, NULL);
+ pthread_setspecific(k3, val);
+
+ printf("%d: Hello after fork2, k1=%d, k2=%d, k3=%d\n", getpid(), k1, k2, k3);
+
+ if (k1 == k2 || k2 == k3) {
+ printf("%d: FAIL inconsistent keys\n", getpid());
+ return 1;
+ }
+
+ printf("%d: OK consistent keys\n", getpid());
+ return 0;
+}
diff --git a/nsswitch/wscript_build b/nsswitch/wscript_build
index 3247b6c2b7c3..4e62bb4c9461 100644
--- a/nsswitch/wscript_build
+++ b/nsswitch/wscript_build
@@ -15,6 +15,11 @@ if bld.CONFIG_SET('HAVE_PTHREAD'):
deps='wbclient pthread',
for_selftest=True
)
+ bld.SAMBA_BINARY('b15464-testcase',
+ source='b15464-testcase.c',
+ deps='replace pthread dl',
+ for_selftest=True
+ )
# The nss_wrapper code relies strictly on the linux implementation and
# name, so compile but do not install a copy under this name.
diff --git a/selftest/knownfail.d/b15464_testcase b/selftest/knownfail.d/b15464_testcase
new file mode 100644
index 000000000000..94dd7db7c2a5
--- /dev/null
+++ b/selftest/knownfail.d/b15464_testcase
@@ -0,0 +1 @@
+^b15464_testcase.run.b15464-testcase
diff --git a/source3/selftest/tests.py b/source3/selftest/tests.py
index 0c834ed48b5e..ea17ead3eda7 100755
--- a/source3/selftest/tests.py
+++ b/source3/selftest/tests.py
@@ -67,6 +67,8 @@ except KeyError:
samba4bindir = bindir()
config_h = os.path.join(samba4bindir, "default/include/config.h")
+bbdir = os.path.join(srcdir(), "testprogs/blackbox")
+
# check available features
config_hash = dict()
f = open(config_h, 'r')
@@ -936,6 +938,10 @@ if with_pthreadpool:
[os.path.join(samba3srcdir,
"script/tests/test_libwbclient_threads.sh"),
"$DOMAIN", "$DC_USERNAME"])
+ plantestsuite("b15464_testcase", "none",
+ [os.path.join(bbdir, "b15464-testcase.sh"),
+ binpath("b15464-testcase"),
+ binpath("plugins/libnss_winbind.so.2")])
plantestsuite("samba3.test_nfs4_acl", "none",
[os.path.join(bindir(), "test_nfs4_acls"),
diff --git a/testprogs/blackbox/b15464-testcase.sh b/testprogs/blackbox/b15464-testcase.sh
new file mode 100755
index 000000000000..b0c88260d4cc
--- /dev/null
+++ b/testprogs/blackbox/b15464-testcase.sh
@@ -0,0 +1,21 @@
+#!/bin/sh
+# Blackbox wrapper for bug 15464
+# Copyright (C) 2023 Stefan Metzmacher
+
+if [ $# -lt 2 ]; then
+ cat <<EOF
+Usage: b15464-testcase.sh B15464_TESTCASE LIBNSS_WINBIND
+EOF
+ exit 1
+fi
+
+b15464_testcase=$1
+libnss_winbind=$2
+shift 2
+failed=0
+
+. $(dirname $0)/subunit.sh
+
+testit "run b15464-testcase" $VALGRIND $b15464_testcase $libnss_winbind || failed=$(expr $failed + 1)
+
+testok $0 $failed
--
2.34.1
From 08728ee7847d7864d4c72a4ac1ddfeca78934326 Mon Sep 17 00:00:00 2001
From: Stefan Metzmacher <metze@samba.org>
Date: Thu, 7 Sep 2023 16:02:32 +0200
Subject: [PATCH 2/5] nsswitch/wb_common.c: fix build without HAVE_PTHREAD
BUG: https://bugzilla.samba.org/show_bug.cgi?id=15464
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
(cherry picked from commit 4faf806412c4408db25448b1f67c09359ec2f81f)
---
nsswitch/wb_common.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/nsswitch/wb_common.c b/nsswitch/wb_common.c
index d569e761ebe4..c382a44c1209 100644
--- a/nsswitch/wb_common.c
+++ b/nsswitch/wb_common.c
@@ -104,7 +104,6 @@ static void wb_thread_ctx_initialize(void)
wb_thread_ctx_destructor);
assert(ret == 0);
}
-#endif
static struct winbindd_context *get_wb_thread_ctx(void)
{
@@ -139,6 +138,7 @@ static struct winbindd_context *get_wb_thread_ctx(void)
}
return ctx;
}
+#endif /* HAVE_PTHREAD */
static struct winbindd_context *get_wb_global_ctx(void)
{
--
2.34.1
From d1f43cd4cc6aeb2ac9fcaee9aa512012ca92ecb3 Mon Sep 17 00:00:00 2001
From: Stefan Metzmacher <metze@samba.org>
Date: Fri, 8 Sep 2023 09:53:42 +0200
Subject: [PATCH 3/5] nsswitch/wb_common.c: winbind_destructor can always use
get_wb_global_ctx()
The HAVE_PTHREAD logic inside of get_wb_global_ctx() will do all
required magic.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=15464
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
(cherry picked from commit 836823e5047d0eb18e66707386ba03b812adfaf8)
---
nsswitch/wb_common.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/nsswitch/wb_common.c b/nsswitch/wb_common.c
index c382a44c1209..d56e48d9bdb8 100644
--- a/nsswitch/wb_common.c
+++ b/nsswitch/wb_common.c
@@ -246,14 +246,10 @@ static void winbind_destructor(void)
return;
}
-#ifdef HAVE_PTHREAD_H
- ctx = (struct winbindd_context *)pthread_getspecific(wb_global_ctx.key);
+ ctx = get_wb_global_ctx();
if (ctx == NULL) {
return;
}
-#else
- ctx = get_wb_global_ctx();
-#endif
winbind_close_sock(ctx);
}
--
2.34.1
From 6e29ea5b9efe5cf166cc9d633c1dc4eb8f192736 Mon Sep 17 00:00:00 2001
From: Stefan Metzmacher <metze@samba.org>
Date: Fri, 8 Sep 2023 09:56:47 +0200
Subject: [PATCH 4/5] nsswitch/wb_common.c: don't operate on a stale
wb_global_ctx.key
If nss_winbind is loaded into a process that uses fork multiple times
without any further calls into nss_winbind, wb_atfork_child handler
was using a wb_global_ctx.key that was no longer registered in the
pthread library, so we operated on a slot that was potentially
reused by other libraries or the main application. Which is likely
to cause memory corruption.
So we better don't call pthread_key_delete() in wb_atfork_child().
BUG: https://bugzilla.samba.org/show_bug.cgi?id=15464
Reported-by: Krzysztof Piotr Oledzki <ole@ans.pl>
Tested-by: Krzysztof Piotr Oledzki <ole@ans.pl>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
(cherry picked from commit 91b30a7261e6455d3a4f31728c23e4849e3945b9)
---
nsswitch/wb_common.c | 5 -----
selftest/knownfail.d/b15464_testcase | 1 -
2 files changed, 6 deletions(-)
delete mode 100644 selftest/knownfail.d/b15464_testcase
diff --git a/nsswitch/wb_common.c b/nsswitch/wb_common.c
index d56e48d9bdb8..38f9f334016b 100644
--- a/nsswitch/wb_common.c
+++ b/nsswitch/wb_common.c
@@ -76,11 +76,6 @@ static void wb_atfork_child(void)
winbind_close_sock(ctx);
free(ctx);
-
- ret = pthread_key_delete(wb_global_ctx.key);
- assert(ret == 0);
-
- wb_global_ctx.control = (pthread_once_t)PTHREAD_ONCE_INIT;
}
static void wb_thread_ctx_destructor(void *p)
diff --git a/selftest/knownfail.d/b15464_testcase b/selftest/knownfail.d/b15464_testcase
deleted file mode 100644
index 94dd7db7c2a5..000000000000
--- a/selftest/knownfail.d/b15464_testcase
+++ /dev/null
@@ -1 +0,0 @@
-^b15464_testcase.run.b15464-testcase
--
2.34.1
From 61ca2c66e0a3c837f2c542b8d9321a8d8cd03382 Mon Sep 17 00:00:00 2001
From: Stefan Metzmacher <metze@samba.org>
Date: Thu, 7 Sep 2023 15:59:59 +0200
Subject: [PATCH 5/5] nsswitch/wb_common.c: fix socket fd and memory leaks of
global state
When we are called in wb_atfork_child() or winbind_destructor(),
wb_thread_ctx_destructor() is not called for the global state
of the current nor any other thread, which means we would
leak the related memory and socket fds.
Now we maintain a global list protected by a global mutex.
We traverse the list and close all socket fds, which are no
longer used (winbind_destructor) or no longer valid in the
current process (wb_atfork_child), in addition we 'autofree'
the ones, which are only visible internally as global (per thread)
context.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=15464
Tested-by: Krzysztof Piotr Oledzki <ole@ans.pl>
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
Autobuild-User(master): Stefan Metzmacher <metze@samba.org>
Autobuild-Date(master): Thu Sep 14 18:53:07 UTC 2023 on atb-devel-224
(cherry picked from commit 4af3faace481d23869b64485b791bdd43d8972c5)
---
nsswitch/wb_common.c | 143 ++++++++++++++++++++++++++++++++++---------
1 file changed, 113 insertions(+), 30 deletions(-)
diff --git a/nsswitch/wb_common.c b/nsswitch/wb_common.c
index 38f9f334016b..b7f84435a4ee 100644
--- a/nsswitch/wb_common.c
+++ b/nsswitch/wb_common.c
@@ -26,6 +26,7 @@
#include "replace.h"
#include "system/select.h"
#include "winbind_client.h"
+#include "lib/util/dlinklist.h"
#include <assert.h>
#ifdef HAVE_PTHREAD_H
@@ -37,67 +38,112 @@ static __thread char client_name[32];
/* Global context */
struct winbindd_context {
+ struct winbindd_context *prev, *next;
int winbindd_fd; /* winbind file descriptor */
bool is_privileged; /* using the privileged socket? */
pid_t our_pid; /* calling process pid */
+ bool autofree; /* this is a thread global context */
};
static struct wb_global_ctx {
- bool initialized;
#ifdef HAVE_PTHREAD
pthread_once_t control;
pthread_key_t key;
+ bool key_initialized;
+#ifdef PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP
+#define WB_GLOBAL_MUTEX_INITIALIZER PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP
#else
- bool dummy;
+#define WB_GLOBAL_MUTEX_INITIALIZER PTHREAD_MUTEX_INITIALIZER
#endif
+#define WB_GLOBAL_LIST_LOCK do { \
+ int __pret = pthread_mutex_lock(&wb_global_ctx.list_mutex); \
+ assert(__pret == 0); \
+} while(0)
+#define WB_GLOBAL_LIST_UNLOCK do { \
+ int __pret = pthread_mutex_unlock(&wb_global_ctx.list_mutex); \
+ assert(__pret == 0); \
+} while(0)
+ pthread_mutex_t list_mutex;
+#else /* => not HAVE_PTHREAD */
+#define WB_GLOBAL_LIST_LOCK do { } while(0)
+#define WB_GLOBAL_LIST_UNLOCK do { } while(0)
+#endif /* not HAVE_PTHREAD */
+ struct winbindd_context *list;
} wb_global_ctx = {
#ifdef HAVE_PTHREAD
.control = PTHREAD_ONCE_INIT,
+ .list_mutex = WB_GLOBAL_MUTEX_INITIALIZER,
#endif
+ .list = NULL,
};
static void winbind_close_sock(struct winbindd_context *ctx);
+static void winbind_ctx_free_locked(struct winbindd_context *ctx);
+static void winbind_cleanup_list(void);
#ifdef HAVE_PTHREAD
static void wb_thread_ctx_initialize(void);
+static void wb_atfork_prepare(void)
+{
+ WB_GLOBAL_LIST_LOCK;
+}
+
+static void wb_atfork_parent(void)
+{
+ WB_GLOBAL_LIST_UNLOCK;
+}
+
static void wb_atfork_child(void)
{
- struct winbindd_context *ctx = NULL;
- int ret;
+ wb_global_ctx.list_mutex = (pthread_mutex_t)WB_GLOBAL_MUTEX_INITIALIZER;
- ctx = (struct winbindd_context *)pthread_getspecific(wb_global_ctx.key);
- if (ctx == NULL) {
- return;
- }
+ if (wb_global_ctx.key_initialized) {
+ int ret;
- ret = pthread_setspecific(wb_global_ctx.key, NULL);
- assert(ret == 0);
+ /*
+ * After a fork the child still believes
+ * it is the same thread as in the parent.
+ * So pthread_getspecific() would return the
+ * value of the thread that called fork().
+ *
+ * But we don't want that behavior, so
+ * we just clear the reference and let
+ * winbind_cleanup_list() below 'autofree'
+ * the parent threads global context.
+ */
+ ret = pthread_setspecific(wb_global_ctx.key, NULL);
+ assert(ret == 0);
+ }
- winbind_close_sock(ctx);
- free(ctx);
+ /*
+ * But we need to close/cleanup the global state
+ * of the parents threads.
+ */
+ winbind_cleanup_list();
}
static void wb_thread_ctx_destructor(void *p)
{
struct winbindd_context *ctx = (struct winbindd_context *)p;
- winbind_close_sock(ctx);
- free(ctx);
+ winbindd_ctx_free(ctx);
}
static void wb_thread_ctx_initialize(void)
{
int ret;
- ret = pthread_atfork(NULL,
- NULL,
+ ret = pthread_atfork(wb_atfork_prepare,
+ wb_atfork_parent,
wb_atfork_child);
assert(ret == 0);
ret = pthread_key_create(&wb_global_ctx.key,
wb_thread_ctx_destructor);
assert(ret == 0);
+
+ wb_global_ctx.key_initialized = true;
}
static struct winbindd_context *get_wb_thread_ctx(void)
@@ -123,9 +169,14 @@ static struct winbindd_context *get_wb_thread_ctx(void)
*ctx = (struct winbindd_context) {
.winbindd_fd = -1,
.is_privileged = false,
- .our_pid = 0
+ .our_pid = 0,
+ .autofree = true,
};
+ WB_GLOBAL_LIST_LOCK;
+ DLIST_ADD_END(wb_global_ctx.list, ctx);
+ WB_GLOBAL_LIST_UNLOCK;
+
ret = pthread_setspecific(wb_global_ctx.key, ctx);
if (ret != 0) {
free(ctx);
@@ -142,7 +193,8 @@ static struct winbindd_context *get_wb_global_ctx(void)
static struct winbindd_context _ctx = {
.winbindd_fd = -1,
.is_privileged = false,
- .our_pid = 0
+ .our_pid = 0,
+ .autofree = false,
};
#endif
@@ -150,9 +202,11 @@ static struct winbindd_context *get_wb_global_ctx(void)
ctx = get_wb_thread_ctx();
#else
ctx = &_ctx;
+ if (ctx->prev == NULL && ctx->next == NULL) {
+ DLIST_ADD_END(wb_global_ctx.list, ctx);
+ }
#endif
- wb_global_ctx.initialized = true;
return ctx;
}
@@ -226,6 +280,30 @@ static void winbind_close_sock(struct winbindd_context *ctx)
}
}
+static void winbind_ctx_free_locked(struct winbindd_context *ctx)
+{
+ winbind_close_sock(ctx);
+ DLIST_REMOVE(wb_global_ctx.list, ctx);
+ free(ctx);
+}
+
+static void winbind_cleanup_list(void)
+{
+ struct winbindd_context *ctx = NULL, *next = NULL;
+
+ WB_GLOBAL_LIST_LOCK;
+ for (ctx = wb_global_ctx.list; ctx != NULL; ctx = next) {
+ next = ctx->next;
+
+ if (ctx->autofree) {
+ winbind_ctx_free_locked(ctx);
+ } else {
+ winbind_close_sock(ctx);
+ }
+ }
+ WB_GLOBAL_LIST_UNLOCK;
+}
+
/* Destructor for global context to ensure fd is closed */
#ifdef HAVE_DESTRUCTOR_ATTRIBUTE
@@ -235,18 +313,18 @@ __attribute__((destructor))
#endif
static void winbind_destructor(void)
{
- struct winbindd_context *ctx;
-
- if (!wb_global_ctx.initialized) {
- return;
+#ifdef HAVE_PTHREAD
+ if (wb_global_ctx.key_initialized) {
+ int ret;
+ ret = pthread_key_delete(wb_global_ctx.key);
+ assert(ret == 0);
+ wb_global_ctx.key_initialized = false;
}
- ctx = get_wb_global_ctx();
- if (ctx == NULL) {
- return;
- }
+ wb_global_ctx.control = (pthread_once_t)PTHREAD_ONCE_INIT;
+#endif /* HAVE_PTHREAD */
- winbind_close_sock(ctx);
+ winbind_cleanup_list();
}
#define CONNECT_TIMEOUT 30
@@ -928,11 +1006,16 @@ struct winbindd_context *winbindd_ctx_create(void)
ctx->winbindd_fd = -1;
+ WB_GLOBAL_LIST_LOCK;
+ DLIST_ADD_END(wb_global_ctx.list, ctx);
+ WB_GLOBAL_LIST_UNLOCK;
+
return ctx;
}
void winbindd_ctx_free(struct winbindd_context *ctx)
{
- winbind_close_sock(ctx);
- free(ctx);
+ WB_GLOBAL_LIST_LOCK;
+ winbind_ctx_free_locked(ctx);
+ WB_GLOBAL_LIST_UNLOCK;
}
--
2.34.1

8
SPECS/samba.spec
View File

@ -138,7 +138,7 @@
%define samba_requires_eq() %(LC_ALL="C" echo '%*' | xargs -r rpm -q --qf 'Requires: %%{name} = %%{epoch}:%%{version}\\n' | sed -e 's/ (none):/ /' -e 's/ 0:/ /' | grep -v "is not")
%global samba_version 4.18.6
%global baserelease 2
%global baserelease 3
# This should be rc1 or %%nil
%global pre_release %nil
@ -241,6 +241,8 @@ Patch1: CVE-2023-3961-s3-smbd-Catch-any-incoming-pipe-path-that.patch
Patch2: CVE-2023-4091-smbtorture-test-overwrite-dispositions-on.patch
# https://attachments.samba.org/attachment.cgi?id=18136
Patch3: CVE-2023-42669-s4-rpc_server-Disable-rpcecho-server-by.patch
# https://attachments.samba.org/attachment.cgi?id=18104
Patch4: memory-corruption-since-samba-4-18.patch
Requires(pre): /usr/sbin/groupadd
@ -4335,6 +4337,10 @@ fi
%endif
%changelog
* Wed Feb 21 2024 Eduard Abdullin <eabdullin@almalinux.org> - 4.18.6-3.alma.1
- Fix libnss_winbind causes memory corruption since samba-4.18,
impacts sendmail, zabbix, potentially more
* Thu Nov 23 2023 Eduard Abdullin <eabdullin@almalinux.org> - 4.18.6-2.alma.1
- CVE-2023-3961:s3:smbd: Catch any incoming pipe path that
could exit socket_dir.