diff options
Diffstat (limited to 'poky/meta/recipes-kernel/lttng/lttng-tools/0007-Fix-getgrnam-is-not-MT-Safe-use-getgrnam_r.patch')
-rw-r--r-- | poky/meta/recipes-kernel/lttng/lttng-tools/0007-Fix-getgrnam-is-not-MT-Safe-use-getgrnam_r.patch | 345 |
1 files changed, 345 insertions, 0 deletions
diff --git a/poky/meta/recipes-kernel/lttng/lttng-tools/0007-Fix-getgrnam-is-not-MT-Safe-use-getgrnam_r.patch b/poky/meta/recipes-kernel/lttng/lttng-tools/0007-Fix-getgrnam-is-not-MT-Safe-use-getgrnam_r.patch new file mode 100644 index 000000000..5437de26e --- /dev/null +++ b/poky/meta/recipes-kernel/lttng/lttng-tools/0007-Fix-getgrnam-is-not-MT-Safe-use-getgrnam_r.patch @@ -0,0 +1,345 @@ +From 10e8001ad876d8cb3b5a17c7492e713bbc047975 Mon Sep 17 00:00:00 2001 +From: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com> +Date: Thu, 28 Mar 2019 18:31:29 -0400 +Subject: [PATCH] Fix: getgrnam is not MT-Safe, use getgrnam_r + +Running the test suite under a Yocto musl build resulted in musl +coredump due to double freeing. + +We get the following backtraces: + +0 a_crash () at ./arch/x86_64/atomic_arch.h:108 +1 unmap_chunk (self=<optimized out>) at src/malloc/malloc.c:515 +2 free (p=<optimized out>) at src/malloc/malloc.c:526 +3 0x00007f46d9dc3849 in __getgrent_a (f=f@entry=0x7f46d9d1f7e0, gr=gr@entry=0x7f46d9e24460 <gr>, line=line@entry=0x7f46d9e26058 <line>, size=size@entry=0x7f46d92db550, mem=mem@entry=0x7f46d9e26050 <mem>, nmem=nmem@entry=0x7f46d92db558, res=0x7f46d92db548) at src/passwd/getgrent_a.c:45 +4 0x00007f46d9dc2e6b in __getgr_a (name=0x487242 "tracing", gid=gid@entry=0, gr=gr@entry=0x7f46d9e24460 <gr>, buf=buf@entry=0x7f46d9e26058 <line>, size=size@entry=0x7f46d92db550, mem=mem@entry=0x7f46d9e26050 <mem>, nmem=0x7f46d92db558, res=0x7f46d92db548) at src/passwd/getgr_a.c:30 +5 0x00007f46d9dc3733 in getgrnam (name=<optimized out>) at src/passwd/getgrent.c:37 +6 0x0000000000460b29 in utils_get_group_id (name=<optimized out>) at ../../../lttng-tools-2.10.6/src/common/utils.c:1241 +7 0x000000000044ee69 in thread_manage_health (data=<optimized out>) at ../../../../lttng-tools-2.10.6/src/bin/lttng-sessiond/main.c:4115 +8 0x00007f46d9de1541 in start (p=<optimized out>) at src/thread/pthread_create.c:195 +9 0x00007f46d9dee661 in __clone () at src/thread/x86_64/clone.s:22 + +From another run: + +0 a_crash () at ./arch/x86_64/atomic_arch.h:108 +1 unmap_chunk (self=<optimized out>) at src/malloc/malloc.c:515 +2 free (p=<optimized out>) at src/malloc/malloc.c:526 +3 0x00007f5abc210849 in __getgrent_a (f=f@entry=0x7f5abc2733e0, gr=gr@entry=0x7f5abc271460 <gr>, line=line@entry=0x7f5abc273058 <line>, size=size@entry=0x7f5abaef5510, mem=mem@entry=0x7f5abc273050 <mem>, nmem=nmem@entry=0x7f5abaef5518, res=0x7f5abaef5508) at src/passwd/getgrent_a.c:45 +4 0x00007f5abc20fe6b in __getgr_a (name=0x487242 "tracing", gid=gid@entry=0, gr=gr@entry=0x7f5abc271460 <gr>, buf=buf@entry=0x7f5abc273058 <line>, size=size@entry=0x7f5abaef5510, mem=mem@entry=0x7f5abc273050 <mem>, nmem=0x7f5abaef5518, res=0x7f5abaef5508) at src/passwd/getgr_a.c:30 +5 0x00007f5abc210733 in getgrnam (name=<optimized out>) at src/passwd/getgrent.c:37 +6 0x0000000000460b29 in utils_get_group_id (name=<optimized out>) at ../../../lttng-tools-2.10.6/src/common/utils.c:1241 +7 0x000000000042dee4 in notification_channel_socket_create () at ../../../../lttng-tools-2.10.6/src/bin/lttng-sessiond/notification-thread.c:238 +8 init_thread_state (state=0x7f5abaef5560, handle=0x7f5abbf9be40) at ../../../../lttng-tools-2.10.6/src/bin/lttng-sessiond/notification-thread.c:375 +9 thread_notification (data=0x7f5abbf9be40) at ../../../../lttng-tools-2.10.6/src/bin/lttng-sessiond/notification-thread.c:495 +10 0x00007f5abc22e541 in start (p=<optimized out>) at src/thread/pthread_create.c:195 +11 0x00007f5abc23b661 in __clone () at src/thread/x86_64/clone.s:22 + +The problem was easily reproducible (~6 crash on ~300 runs). A prototype fix +using mutex around the getgrnam yielded no crash in over 1000 runs. This +patch yielded the same results as the prototype fix. + +Unfortunately we cannot rely on a mutex in liblttng-ctl since we cannot +enforce the locking for the application using the lib. + +Use getgrnam_r instead. + +The previous implementation of utils_get_group_id returned the gid of +the root group (0) on error/not found. lttng_check_tracing_group needs +to know if an error/not found occured, returning the root group is not +enough. We now return the gid via the passed parameter. The caller is +responsible for either defaulting to the root group or propagating the +error. + +We also do not want to warn when used in liblttng-ctl context. We might +want to move the warning elsewhere in the future. For now, pass a bool +if we need to warn or not. + +Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com> +--- + src/bin/lttng-consumerd/health-consumerd.c | 10 ++- + src/bin/lttng-relayd/health-relayd.c | 20 ++++-- + src/bin/lttng-sessiond/main.c | 24 +++++-- + src/bin/lttng-sessiond/notification-thread.c | 10 ++- + src/common/utils.c | 75 +++++++++++++++++--- + src/common/utils.h | 4 +- + src/lib/lttng-ctl/lttng-ctl.c | 8 +-- + 7 files changed, 122 insertions(+), 29 deletions(-) + +diff --git a/src/bin/lttng-consumerd/health-consumerd.c b/src/bin/lttng-consumerd/health-consumerd.c +index 1e2f31e4..6045401a 100644 +--- a/src/bin/lttng-consumerd/health-consumerd.c ++++ b/src/bin/lttng-consumerd/health-consumerd.c +@@ -184,8 +184,14 @@ void *thread_manage_health(void *data) + is_root = !getuid(); + if (is_root) { + /* lttng health client socket path permissions */ +- ret = chown(health_unix_sock_path, 0, +- utils_get_group_id(tracing_group_name)); ++ gid_t gid; ++ ++ ret = utils_get_group_id(tracing_group_name, true, &gid); ++ if (ret) { ++ gid = 0; /* Default to root group. */ ++ } ++ ++ ret = chown(health_unix_sock_path, 0, gid); + if (ret < 0) { + ERR("Unable to set group on %s", health_unix_sock_path); + PERROR("chown"); +diff --git a/src/bin/lttng-relayd/health-relayd.c b/src/bin/lttng-relayd/health-relayd.c +index ba996621..962e88c4 100644 +--- a/src/bin/lttng-relayd/health-relayd.c ++++ b/src/bin/lttng-relayd/health-relayd.c +@@ -105,8 +105,14 @@ static int create_lttng_rundir_with_perm(const char *rundir) + int is_root = !getuid(); + + if (is_root) { +- ret = chown(rundir, 0, +- utils_get_group_id(tracing_group_name)); ++ gid_t gid; ++ ++ ret = utils_get_group_id(tracing_group_name, true, &gid); ++ if (ret) { ++ gid = 0; /* Default to root group.*/ ++ } ++ ++ ret = chown(rundir, 0, gid); + if (ret < 0) { + ERR("Unable to set group on %s", rundir); + PERROR("chown"); +@@ -256,8 +262,14 @@ void *thread_manage_health(void *data) + is_root = !getuid(); + if (is_root) { + /* lttng health client socket path permissions */ +- ret = chown(health_unix_sock_path, 0, +- utils_get_group_id(tracing_group_name)); ++ gid_t gid; ++ ++ ret = utils_get_group_id(tracing_group_name, true, &gid); ++ if (ret) { ++ gid = 0; /* Default to root group */ ++ } ++ ++ ret = chown(health_unix_sock_path, 0, gid); + if (ret < 0) { + ERR("Unable to set group on %s", health_unix_sock_path); + PERROR("chown"); +diff --git a/src/bin/lttng-sessiond/main.c b/src/bin/lttng-sessiond/main.c +index fa6fa483..49307064 100644 +--- a/src/bin/lttng-sessiond/main.c ++++ b/src/bin/lttng-sessiond/main.c +@@ -4112,8 +4112,14 @@ static void *thread_manage_health(void *data) + + if (is_root) { + /* lttng health client socket path permissions */ +- ret = chown(config.health_unix_sock_path.value, 0, +- utils_get_group_id(config.tracing_group_name.value)); ++ gid_t gid; ++ ++ ret = utils_get_group_id(config.tracing_group_name.value, true, &gid); ++ if (ret) { ++ gid = 0; /* Default to root group */ ++ } ++ ++ ret = chown(config.health_unix_sock_path.value, 0, &gid); + if (ret < 0) { + ERR("Unable to set group on %s", config.health_unix_sock_path.value); + PERROR("chown"); +@@ -5238,7 +5244,10 @@ static int set_permissions(char *rundir) + int ret; + gid_t gid; + +- gid = utils_get_group_id(config.tracing_group_name.value); ++ ret = utils_get_group_id(config.tracing_group_name.value, true, &gid); ++ if (ret) { ++ gid = 0; /* Default to root group */ ++ } + + /* Set lttng run dir */ + ret = chown(rundir, 0, gid); +@@ -5349,7 +5358,14 @@ static int set_consumer_sockets(struct consumer_data *consumer_data) + goto error; + } + if (is_root) { +- ret = chown(path, 0, utils_get_group_id(config.tracing_group_name.value)); ++ gid_t gid; ++ ++ ret = utils_get_group_id(config.tracing_group_name.value, true, &gid); ++ if (ret) { ++ gid = 0; /* Default to root group */ ++ } ++ ++ ret = chown(path, 0, gid); + if (ret < 0) { + ERR("Unable to set group on %s", path); + PERROR("chown"); +diff --git a/src/bin/lttng-sessiond/notification-thread.c b/src/bin/lttng-sessiond/notification-thread.c +index 92ac597f..18a264d9 100644 +--- a/src/bin/lttng-sessiond/notification-thread.c ++++ b/src/bin/lttng-sessiond/notification-thread.c +@@ -235,8 +235,14 @@ int notification_channel_socket_create(void) + } + + if (getuid() == 0) { +- ret = chown(sock_path, 0, +- utils_get_group_id(config.tracing_group_name.value)); ++ gid_t gid; ++ ++ ret = utils_get_group_id(config.tracing_group_name.value, true, &gid); ++ if (ret) { ++ gid = 0; /* Default to root group. */ ++ } ++ ++ ret = chown(sock_path, 0, gid); + if (ret) { + ERR("Failed to set the notification channel socket's group"); + ret = -1; +diff --git a/src/common/utils.c b/src/common/utils.c +index c0bb031e..778bc00f 100644 +--- a/src/common/utils.c ++++ b/src/common/utils.c +@@ -1231,24 +1231,77 @@ size_t utils_get_current_time_str(const char *format, char *dst, size_t len) + } + + /* +- * Return the group ID matching name, else 0 if it cannot be found. ++ * Return 0 on success and set *gid to the group_ID matching the passed name. ++ * Else -1 if it cannot be found or an error occurred. + */ + LTTNG_HIDDEN +-gid_t utils_get_group_id(const char *name) ++int utils_get_group_id(const char *name, bool warn, gid_t *gid) + { +- struct group *grp; ++ static volatile int warn_once; + +- grp = getgrnam(name); +- if (!grp) { +- static volatile int warn_once; ++ int ret; ++ long sys_len; ++ size_t len; ++ struct group grp; ++ struct group *result; ++ char *buffer = NULL; + +- if (!warn_once) { +- WARN("No tracing group detected"); +- warn_once = 1; ++ /* Get the system limit if it exists */ ++ sys_len = sysconf(_SC_GETGR_R_SIZE_MAX); ++ if (sys_len == -1) { ++ len = 1024; ++ } else { ++ len = (size_t) sys_len; ++ } ++ ++ buffer = malloc(len); ++ if (!buffer) { ++ PERROR("getgrnam_r malloc"); ++ ret = -1; ++ goto error; ++ } ++ ++ while ((ret = getgrnam_r(name, &grp, buffer, len, &result)) == ERANGE) ++ { ++ /* Buffer is not big enough, increase its size. */ ++ size_t new_len = 2 * len; ++ char *new_buffer = NULL; ++ if (new_len < len) { ++ ERR("getgrnam_r buffer size overflow"); ++ ret = -1; ++ goto error; ++ } ++ len = new_len; ++ new_buffer = realloc(buffer, len); ++ if (!new_buffer) { ++ PERROR("getgrnam_r realloc"); ++ ret = -1; ++ goto error; + } +- return 0; ++ buffer = new_buffer; ++ } ++ if (ret != 0) { ++ PERROR("getgrnam_r"); ++ ret = -1; ++ goto error; ++ } ++ ++ /* Group not found. */ ++ if (!result) { ++ ret = -1; ++ goto error; ++ } ++ ++ *gid = result->gr_gid; ++ ret = 0; ++ ++error: ++ free(buffer); ++ if (ret && warn && !warn_once) { ++ WARN("No tracing group detected"); ++ warn_once = 1; + } +- return grp->gr_gid; ++ return ret; + } + + /* +diff --git a/src/common/utils.h b/src/common/utils.h +index 18f19ef1..9c72431d 100644 +--- a/src/common/utils.h ++++ b/src/common/utils.h +@@ -22,6 +22,8 @@ + #include <unistd.h> + #include <stdint.h> + #include <getopt.h> ++#include <stdbool.h> ++#include <sys/types.h> + + #define KIBI_LOG2 10 + #define MEBI_LOG2 20 +@@ -52,7 +54,7 @@ int utils_get_count_order_u64(uint64_t x); + char *utils_get_home_dir(void); + char *utils_get_user_home_dir(uid_t uid); + size_t utils_get_current_time_str(const char *format, char *dst, size_t len); +-gid_t utils_get_group_id(const char *name); ++int utils_get_group_id(const char *name, bool warn, gid_t *gid); + char *utils_generate_optstring(const struct option *long_options, + size_t opt_count); + int utils_create_lock_file(const char *filepath); +diff --git a/src/lib/lttng-ctl/lttng-ctl.c b/src/lib/lttng-ctl/lttng-ctl.c +index 2d84aad9..561b0bcf 100644 +--- a/src/lib/lttng-ctl/lttng-ctl.c ++++ b/src/lib/lttng-ctl/lttng-ctl.c +@@ -208,15 +208,13 @@ end: + LTTNG_HIDDEN + int lttng_check_tracing_group(void) + { +- struct group *grp_tracing; /* no free(). See getgrnam(3) */ +- gid_t *grp_list; ++ gid_t *grp_list, tracing_gid; + int grp_list_size, grp_id, i; + int ret = -1; + const char *grp_name = tracing_group; + + /* Get GID of group 'tracing' */ +- grp_tracing = getgrnam(grp_name); +- if (!grp_tracing) { ++ if (utils_get_group_id(grp_name, false, &tracing_gid)) { + /* If grp_tracing is NULL, the group does not exist. */ + goto end; + } +@@ -241,7 +239,7 @@ int lttng_check_tracing_group(void) + } + + for (i = 0; i < grp_list_size; i++) { +- if (grp_list[i] == grp_tracing->gr_gid) { ++ if (grp_list[i] == tracing_gid) { + ret = 1; + break; + } +-- +2.17.1 + |