The branch, master has been updated
via 4ec0dfc uwrap: Add a workaround for glibc malloc mutex deadlock bug
via d178906 uwrap: First do garbage collection before exporting ids
via 0bfd224 tests: Add setgroups to test_fork_exec
via 2fae075 uwrap: Improve groups string creation
via e242f39 uwrap: Make the unsigned_str smaller
via c1a6e70 uwrap: Fix type of len value
via f1d0330 uwrap: Fix two error messages
via 61139e0 uwrap: Fix a typo
via 6568b53 uwrap: Fix a deadlock if uid_wrapper is not enabled
via 8fb7450 uwrap: Fix logging on optimized build
from 7386dc6 Bump version to 1.2.3
https://git.samba.org/?p=uid_wrapper.git;a=shortlog;h=master
- Log -----------------------------------------------------------------
commit 4ec0dfc252961c411f8770560236a3c27596b3ad
Author: Andreas Schneider <[email protected]>
Date: Fri Jul 21 10:54:05 2017 +0200
uwrap: Add a workaround for glibc malloc mutex deadlock bug
Signed-off-by: Andreas Schneider <[email protected]>
Reviewed-by: Stefan Metzmacher <[email protected]>
commit d178906bcd1f1e2a067e7ddfdf82d24cb49128c7
Author: Andreas Schneider <[email protected]>
Date: Wed Jul 19 16:27:05 2017 +0200
uwrap: First do garbage collection before exporting ids
Signed-off-by: Andreas Schneider <[email protected]>
Reviewed-by: Stefan Metzmacher <[email protected]>
commit 0bfd22468247105523a171ffbbe8678de07b1a55
Author: Andreas Schneider <[email protected]>
Date: Wed Jul 19 16:22:39 2017 +0200
tests: Add setgroups to test_fork_exec
Signed-off-by: Andreas Schneider <[email protected]>
Reviewed-by: Stefan Metzmacher <[email protected]>
commit 2fae075fd0b1a3aef2041118e16755edbedc3a90
Author: Andreas Schneider <[email protected]>
Date: Wed Jul 19 15:57:34 2017 +0200
uwrap: Improve groups string creation
Signed-off-by: Andreas Schneider <[email protected]>
Reviewed-by: Stefan Metzmacher <[email protected]>
commit e242f39a5abf93d9b4b6ffbef1b808e2926739a2
Author: Andreas Schneider <[email protected]>
Date: Wed Jul 19 15:44:32 2017 +0200
uwrap: Make the unsigned_str smaller
Signed-off-by: Andreas Schneider <[email protected]>
Reviewed-by: Stefan Metzmacher <[email protected]>
commit c1a6e70d62aa14efab4bf41ce2230b76aa455807
Author: Andreas Schneider <[email protected]>
Date: Wed Jul 19 15:43:13 2017 +0200
uwrap: Fix type of len value
snprintf return an 'int'.
Signed-off-by: Andreas Schneider <[email protected]>
Reviewed-by: Stefan Metzmacher <[email protected]>
commit f1d03308d84944914318053314112cdfcc6222da
Author: Andreas Schneider <[email protected]>
Date: Wed Jul 19 12:15:16 2017 +0200
uwrap: Fix two error messages
Signed-off-by: Andreas Schneider <[email protected]>
Reviewed-by: Stefan Metzmacher <[email protected]>
commit 61139e06f4479d41bed166a0b2b6185d50a11dd3
Author: Andreas Schneider <[email protected]>
Date: Wed Jul 19 12:14:15 2017 +0200
uwrap: Fix a typo
Signed-off-by: Andreas Schneider <[email protected]>
Reviewed-by: Stefan Metzmacher <[email protected]>
commit 6568b531e58cb387a306c17f9c30ff599c30b81c
Author: Andreas Schneider <[email protected]>
Date: Fri Jul 21 08:28:50 2017 +0200
uwrap: Fix a deadlock if uid_wrapper is not enabled
Signed-off-by: Andreas Schneider <[email protected]>
Reviewed-by: Stefan Metzmacher <[email protected]>
commit 8fb7450712e94a6e1ceaddab4ac2a4d9670d715a
Author: Andreas Schneider <[email protected]>
Date: Fri Jul 21 11:39:59 2017 +0200
uwrap: Fix logging on optimized build
Signed-off-by: Andreas Schneider <[email protected]>
Reviewed-by: Stefan Metzmacher <[email protected]>
-----------------------------------------------------------------------
Summary of changes:
src/uid_wrapper.c | 92 ++++++++++++++++++++++++++++++++++----------------
tests/test_fork_exec.c | 7 ++++
2 files changed, 70 insertions(+), 29 deletions(-)
Changeset truncated at 500 lines:
diff --git a/src/uid_wrapper.c b/src/uid_wrapper.c
index 0e9be96..0d74d20 100644
--- a/src/uid_wrapper.c
+++ b/src/uid_wrapper.c
@@ -825,7 +825,7 @@ static void uwrap_export_ids(struct uwrap_thread *id)
{
char groups_str[GROUP_STRING_SIZE] = {0};
size_t groups_str_size = sizeof(groups_str);
- char unsigned_str[32] = {0};
+ char unsigned_str[16] = {0}; /* We need 10 + 1 (+ 1) */
int i;
/* UIDS */
@@ -851,35 +851,51 @@ static void uwrap_export_ids(struct uwrap_thread *id)
if (id->ngroups > GROUP_MAX_COUNT) {
UWRAP_LOG(UWRAP_LOG_ERROR,
"ERROR: Number of groups (%u) exceeds maximum value "
- "uid_wrapper will handle (%u).",
+ "uid_wrapper can handle (%u).",
id->ngroups,
GROUP_MAX_COUNT);
exit(-1);
}
/* GROUPS */
- snprintf(unsigned_str, sizeof(unsigned_str), "%u", id->ngroups);
- setenv("UID_WRAPPER_INITIAL_GROUPS_COUNT", unsigned_str, 1);
-
for (i = 0; i < id->ngroups; i++) {
size_t groups_str_len = strlen(groups_str);
- size_t groups_str_avail = groups_str_size - groups_str_len;
- size_t len;
+ size_t groups_str_avail = groups_str_size - groups_str_len - 1;
+ int len;
len = snprintf(unsigned_str, sizeof(unsigned_str), ",%u",
id->groups[i]);
if (len <= 1) {
- continue;
+ UWRAP_LOG(UWRAP_LOG_ERROR,
+ "snprintf failed for groups[%d]=%u",
+ i,
+ id->groups[i]);
+ break;
+ }
+ if (((size_t)len) >= groups_str_avail) {
+ UWRAP_LOG(UWRAP_LOG_ERROR,
+ "groups env string is to small for %d groups",
+ i);
+ break;
}
- if (len < groups_str_avail) {
- snprintf(groups_str + groups_str_len,
- groups_str_size - groups_str_len,
- "%s",
- i == 0 ? unsigned_str + 1 : unsigned_str);
+
+ len = snprintf(groups_str + groups_str_len,
+ groups_str_size - groups_str_len,
+ "%s",
+ i == 0 ? unsigned_str + 1 : unsigned_str);
+ if (len < 1) {
+ UWRAP_LOG(UWRAP_LOG_ERROR,
+ "snprintf failed to create groups string at
groups[%d]=%u",
+ i,
+ id->groups[i]);
+ break;
}
}
- if (id->ngroups > 0) {
+ if (id->ngroups == i) {
setenv("UID_WRAPPER_INITIAL_GROUPS", groups_str, 1);
+
+ snprintf(unsigned_str, sizeof(unsigned_str), "%u", id->ngroups);
+ setenv("UID_WRAPPER_INITIAL_GROUPS_COUNT", unsigned_str, 1);
}
}
@@ -887,13 +903,13 @@ static void uwrap_thread_prepare(void)
{
struct uwrap_thread *id = uwrap_tls_id;
+ UWRAP_LOCK_ALL;
+
/* uid_wrapper is loaded but not enabled */
if (id == NULL) {
return;
}
- UWRAP_LOCK_ALL;
-
/*
* What happens if another atfork prepare functions calls a uwrap
* function? So disable it in case another atfork prepare function
@@ -909,6 +925,7 @@ static void uwrap_thread_parent(void)
/* uid_wrapper is loaded but not enabled */
if (id == NULL) {
+ UWRAP_UNLOCK_ALL;
return;
}
@@ -924,11 +941,10 @@ static void uwrap_thread_child(void)
/* uid_wrapper is loaded but not enabled */
if (id == NULL) {
+ UWRAP_UNLOCK_ALL;
return;
}
- uwrap_export_ids(id);
-
/*
* "Garbage collector" - Inspired by DESTRUCTOR.
* All threads (except one which called fork()) are dead now.. Dave
@@ -949,6 +965,8 @@ static void uwrap_thread_child(void)
u = uwrap.ids;
}
+ uwrap_export_ids(id);
+
id->enabled = true;
UWRAP_UNLOCK_ALL;
@@ -1048,8 +1066,8 @@ static void uwrap_init_env(struct uwrap_thread *id)
if (i != ngroups) {
UWRAP_LOG(UWRAP_LOG_ERROR,
"ERROR: The number of groups (%u) passed, "
- "does not the number of groups (%u) we "
- "parsed",
+ "does not match the number of groups (%u) "
+ "we parsed.",
ngroups,
i);
exit(-1);
@@ -1160,7 +1178,7 @@ static void uwrap_init(void)
UWRAP_UNLOCK(uwrap_id);
- UWRAP_LOG(UWRAP_LOG_DEBUG, "Succeccfully initialized uid_wrapper");
+ UWRAP_LOG(UWRAP_LOG_DEBUG, "Successfully initialized uid_wrapper");
}
bool uid_wrapper_enabled(void)
@@ -1333,9 +1351,7 @@ static int uwrap_setreuid_args(uid_t ruid, uid_t euid,
static int uwrap_setreuid_thread(uid_t ruid, uid_t euid)
{
-#ifndef NDEBUG
struct uwrap_thread *id = uwrap_tls_id;
-#endif
uid_t new_ruid = -1, new_euid = -1, new_suid = -1;
int rc;
@@ -1354,9 +1370,7 @@ static int uwrap_setreuid_thread(uid_t ruid, uid_t euid)
#ifdef HAVE_SETREUID
static int uwrap_setreuid(uid_t ruid, uid_t euid)
{
-#ifndef NDEBUG
struct uwrap_thread *id = uwrap_tls_id;
-#endif
uid_t new_ruid = -1, new_euid = -1, new_suid = -1;
int rc;
@@ -1620,9 +1634,7 @@ static int uwrap_setregid_args(gid_t rgid, gid_t egid,
static int uwrap_setregid_thread(gid_t rgid, gid_t egid)
{
-#ifndef NDEBUG
struct uwrap_thread *id = uwrap_tls_id;
-#endif
gid_t new_rgid = -1, new_egid = -1, new_sgid = -1;
int rc;
@@ -1641,9 +1653,7 @@ static int uwrap_setregid_thread(gid_t rgid, gid_t egid)
#ifdef HAVE_SETREGID
static int uwrap_setregid(gid_t rgid, gid_t egid)
{
-#ifndef NDEBUG
struct uwrap_thread *id = uwrap_tls_id;
-#endif
gid_t new_rgid = -1, new_egid = -1, new_sgid = -1;
int rc;
@@ -2281,8 +2291,30 @@ long int syscall (long int sysno, ...)
/****************************
* CONSTRUCTOR
***************************/
+
void uwrap_constructor(void)
{
+ char *glibc_malloc_lock_bug;
+
+ /*
+ * This is a workaround for a bug in glibc < 2.24:
+ *
+ * The child handler for the malloc() function is called and locks the
+ * mutex. Then our child handler is called and we try to call setenv().
+ * setenv() wants to malloc and tries to aquire the lock for malloc and
+ * we end up in a deadlock.
+ *
+ * So as a workaround we need to call malloc once before we setup the
+ * handlers.
+ *
+ * See https://sourceware.org/bugzilla/show_bug.cgi?id=16742
+ */
+ glibc_malloc_lock_bug = malloc(1);
+ if (glibc_malloc_lock_bug == NULL) {
+ exit(-1);
+ }
+ glibc_malloc_lock_bug[0] = '\0';
+
/*
* If we hold a lock and the application forks, then the child
* is not able to unlock the mutex and we are in a deadlock.
@@ -2292,6 +2324,8 @@ void uwrap_constructor(void)
&uwrap_thread_parent,
&uwrap_thread_child);
+ free(glibc_malloc_lock_bug);
+
/* Here is safe place to call uwrap_init() and initialize data
* for main process.
*/
diff --git a/tests/test_fork_exec.c b/tests/test_fork_exec.c
index 36077c4..177f321 100644
--- a/tests/test_fork_exec.c
+++ b/tests/test_fork_exec.c
@@ -6,12 +6,15 @@
#include <cmocka.h>
#include <errno.h>
+#include <grp.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
+#define ARRAY_SIZE(a) (sizeof(a)/sizeof(a[0]))
+
#define TEST_MOCK_EXECUTABLE "mock_exec_uid"
static void test_uwrap_fork_exec(void **state)
@@ -19,6 +22,7 @@ static void test_uwrap_fork_exec(void **state)
pid_t pid;
int rc;
uid_t cp_ruid, cp_euid, cp_suid;
+ gid_t glist[] = {0, 10000, 20000, 40000, 100000};
(void)state; /* unused */
@@ -34,6 +38,9 @@ static void test_uwrap_fork_exec(void **state)
rc = setgid(5000);
assert_return_code(rc, errno);
+ rc = setgroups(ARRAY_SIZE(glist), glist);
+ assert_return_code(rc, errno);
+
pid = fork();
assert_return_code(pid, errno);
--
UID Wrapper Repository
