kmodloader: clean up memory mapping and fix fd leaks in error handling

Signed-off-by: Jo-Philipp Wich <jow@openwrt.org>

diff --git a/kmodloader.c b/kmodloader.c
index 86e3f447c4096b7101ddb640f775e9eb3e8ca89c..2dc795e8b18399bec325fd5fb5899b8b55d87d64 100644 (file)
--- a/kmodloader.c
+++ b/kmodloader.c
@@ -277,29 +277,29 @@ static struct module* get_module_info(const char *module, const char *name)
 {
        int fd = open(module, O_RDONLY);
        unsigned int offset, size;
-       char *map, *strings, *dep = NULL;
-       struct module *m;
+       char *map = MAP_FAILED, *strings, *dep = NULL;
+       struct module *m = NULL;
        struct stat s;
 
        if (fd < 0) {
                ULOG_ERR("failed to open %s\n", module);
-               return NULL;
+               goto out;
        }
 
        if (fstat(fd, &s) == -1) {
                ULOG_ERR("failed to stat %s\n", module);
-               return NULL;
+               goto out;
        }
 
        map = mmap(NULL, s.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
        if (map == MAP_FAILED) {
                ULOG_ERR("failed to mmap %s\n", module);
-               return NULL;
+               goto out;
        }
 
        if (elf_find_section(map, ".modinfo", &offset, &size)) {
                ULOG_ERR("failed to load the .modinfo section from %s\n", module);
-               return NULL;
+               goto out;
        }
 
        strings = map + offset;
@@ -320,10 +320,16 @@ static struct module* get_module_info(const char *module, const char *name)
        }
 
        m = alloc_module(name, dep, s.st_size);
-       if (!m)
-               return NULL;
 
-       m->state = SCANNED;
+       if (m)
+               m->state = SCANNED;
+
+out:
+       if (map != MAP_FAILED)
+               munmap(map, s.st_size);
+
+       if (fd >= 0)
+               close(fd);
 
        return m;
 }
@@ -379,27 +385,28 @@ static int print_modinfo(char *module)
        int fd = open(module, O_RDONLY);
        unsigned int offset, size;
        struct stat s;
-       char *map, *strings;
+       char *map = MAP_FAILED, *strings;
+       int rv = -1;
 
        if (fd < 0) {
                ULOG_ERR("failed to open %s\n", module);
-               return -1;
+               goto out;
        }
 
        if (fstat(fd, &s) == -1) {
                ULOG_ERR("failed to stat %s\n", module);
-               return -1;
+               goto out;
        }
 
        map = mmap(NULL, s.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
        if (map == MAP_FAILED) {
                ULOG_ERR("failed to mmap %s\n", module);
-               return -1;
+               goto out;
        }
 
        if (elf_find_section(map, ".modinfo", &offset, &size)) {
                ULOG_ERR("failed to load the .modinfo section from %s\n", module);
-               return -1;
+               goto out;
        }
 
        strings = map + offset;
@@ -426,7 +433,16 @@ static int print_modinfo(char *module)
                        free(dup);
        }
 
-       return 0;
+       rv = 0;
+
+out:
+       if (map != MAP_FAILED)
+               munmap(map, s.st_size);
+
+       if (fd >= 0)
+               close(fd);
+
+       return rv;
 }
 
 static int deps_available(struct module *m, int verbose)