[dm-devel] [PATCH v5 02/21] libmultipath: fix memory leaks from scandir() use
Martin Wilck
mwilck at suse.com
Fri Nov 2 12:21:06 UTC 2018
scandir() users must not only free the resulting dirent* array,
but also every member. Add a cleanup function, and fix the
existing users of scandir() in libmultipath.
Add a small helper macro for casting function pointers to the
type pthread_cleanup_push() expects.
Reviewed-by: Benjamin Marzinski <bmarzins at redhat.com>
Signed-off-by: Martin Wilck <mwilck at suse.com>
---
libmultipath/config.c | 10 ++++------
libmultipath/foreign.c | 5 ++++-
libmultipath/foreign/nvme.c | 6 +++++-
libmultipath/sysfs.c | 5 ++++-
libmultipath/util.c | 9 +++++++++
libmultipath/util.h | 9 +++++++++
6 files changed, 35 insertions(+), 9 deletions(-)
diff --git a/libmultipath/config.c b/libmultipath/config.c
index 0aef186a..5af7af58 100644
--- a/libmultipath/config.c
+++ b/libmultipath/config.c
@@ -639,17 +639,13 @@ free_config (struct config * conf)
FREE(conf);
}
-static void free_namelist(void *nl)
-{
- free(nl);
-}
-
/* if multipath fails to process the config directory, it should continue,
* with just a warning message */
static void
process_config_dir(struct config *conf, vector keywords, char *dir)
{
struct dirent **namelist;
+ struct scandir_result sr;
int i, n;
char path[LINE_MAX];
int old_hwtable_size;
@@ -669,7 +665,9 @@ process_config_dir(struct config *conf, vector keywords, char *dir)
return;
} else if (n == 0)
return;
- pthread_cleanup_push(free_namelist, namelist);
+ sr.di = namelist;
+ sr.n = n;
+ pthread_cleanup_push_cast(free_scandir_result, &sr);
for (i = 0; i < n; i++) {
if (!strstr(namelist[i]->d_name, ".conf"))
continue;
diff --git a/libmultipath/foreign.c b/libmultipath/foreign.c
index 80b399ba..48e8d247 100644
--- a/libmultipath/foreign.c
+++ b/libmultipath/foreign.c
@@ -115,6 +115,7 @@ static int _init_foreign(const char *multipath_dir)
{
char pathbuf[PATH_MAX];
struct dirent **di;
+ struct scandir_result sr;
int r, i;
foreigns = vector_alloc();
@@ -135,7 +136,9 @@ static int _init_foreign(const char *multipath_dir)
return -r;
}
- pthread_cleanup_push(free, di);
+ sr.di = di;
+ sr.n = r;
+ pthread_cleanup_push_cast(free_scandir_result, &sr);
for (i = 0; i < r; i++) {
const char *msg, *fn, *c;
struct foreign *fgn;
diff --git a/libmultipath/foreign/nvme.c b/libmultipath/foreign/nvme.c
index 8887a755..c753a747 100644
--- a/libmultipath/foreign/nvme.c
+++ b/libmultipath/foreign/nvme.c
@@ -27,6 +27,7 @@
#include <dirent.h>
#include <errno.h>
#include <ctype.h>
+#include "util.h"
#include "vector.h"
#include "generic.h"
#include "foreign.h"
@@ -534,6 +535,7 @@ static void _find_controllers(struct context *ctx, struct nvme_map *map)
{
char pathbuf[PATH_MAX], realbuf[PATH_MAX];
struct dirent **di = NULL;
+ struct scandir_result sr;
struct udev_device *subsys;
struct nvme_path *path;
int r, i, n;
@@ -568,7 +570,9 @@ static void _find_controllers(struct context *ctx, struct nvme_map *map)
return;
}
- pthread_cleanup_push(free, di);
+ sr.di = di;
+ sr.n = r;
+ pthread_cleanup_push_cast(free_scandir_result, &sr);
for (i = 0; i < r; i++) {
char *fn = di[i]->d_name;
struct udev_device *ctrl, *udev;
diff --git a/libmultipath/sysfs.c b/libmultipath/sysfs.c
index b7dacaad..558c8d6a 100644
--- a/libmultipath/sysfs.c
+++ b/libmultipath/sysfs.c
@@ -303,6 +303,7 @@ static void close_fd(void *arg)
bool sysfs_is_multipathed(const struct path *pp)
{
char pathbuf[PATH_MAX];
+ struct scandir_result sr;
struct dirent **di;
int n, r, i;
bool found = false;
@@ -323,7 +324,9 @@ bool sysfs_is_multipathed(const struct path *pp)
return false;
}
- pthread_cleanup_push(free, di);
+ sr.di = di;
+ sr.n = r;
+ pthread_cleanup_push_cast(free_scandir_result, &sr);
for (i = 0; i < r && !found; i++) {
long fd;
int nr;
diff --git a/libmultipath/util.c b/libmultipath/util.c
index d08112db..66c47611 100644
--- a/libmultipath/util.c
+++ b/libmultipath/util.c
@@ -496,3 +496,12 @@ void set_max_fds(int max_fds)
}
}
}
+
+void free_scandir_result(struct scandir_result *res)
+{
+ int i;
+
+ for (i = 0; i < res->n; i++)
+ FREE(res->di[i]);
+ FREE(res->di);
+}
diff --git a/libmultipath/util.h b/libmultipath/util.h
index c2462950..a818e29a 100644
--- a/libmultipath/util.h
+++ b/libmultipath/util.h
@@ -30,4 +30,13 @@ void set_max_fds(int max_fds);
#define safe_snprintf(var, size, format, args...) \
snprintf(var, size, format, ##args) >= size
+#define pthread_cleanup_push_cast(f, arg) \
+ pthread_cleanup_push(((void (*)(void *))&f), (arg))
+
+struct scandir_result {
+ struct dirent **di;
+ int n;
+};
+void free_scandir_result(struct scandir_result *);
+
#endif /* _UTIL_H */
--
2.19.1
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