Coverity pointed out that we shouldn't be using stat()/open(), as the file might have vanished or changed in between those two calls. So modify it to open()/fstat() instead.
Signed-off-by: Hannes Reinecke <[email protected]> --- libmultipath/sysfs.c | 59 +++++++++++++++++++++++++++++----------------------- 1 file changed, 33 insertions(+), 26 deletions(-) diff --git a/libmultipath/sysfs.c b/libmultipath/sysfs.c index de7df40..a74de9f 100644 --- a/libmultipath/sysfs.c +++ b/libmultipath/sysfs.c @@ -57,30 +57,31 @@ ssize_t sysfs_attr_get_value(struct udev_device *dev, const char *attr_name, snprintf(devpath, PATH_SIZE, "%s/%s", udev_device_get_syspath(dev), attr_name); condlog(4, "open '%s'", devpath); - if (stat(devpath, &statbuf) != 0) { + /* read attribute value */ + fd = open(devpath, O_RDONLY); + if (fd < 0) { + condlog(4, "attribute '%s' can not be opened: %s", + devpath, strerror(errno)); + return -errno; + } + if (fstat(fd, &statbuf) < 0) { condlog(4, "stat '%s' failed: %s", devpath, strerror(errno)); + close(fd); return -ENXIO; } - /* skip directories */ if (S_ISDIR(statbuf.st_mode)) { condlog(4, "%s is a directory", devpath); + close(fd); return -EISDIR; } - /* skip non-writeable files */ if ((statbuf.st_mode & S_IRUSR) == 0) { condlog(4, "%s is not readable", devpath); + close(fd); return -EPERM; } - /* read attribute value */ - fd = open(devpath, O_RDONLY); - if (fd < 0) { - condlog(4, "attribute '%s' can not be opened: %s", - devpath, strerror(errno)); - return -errno; - } size = read(fd, value, value_len); if (size < 0) { condlog(4, "read from %s failed: %s", devpath, strerror(errno)); @@ -112,30 +113,33 @@ ssize_t sysfs_bin_attr_get_value(struct udev_device *dev, const char *attr_name, snprintf(devpath, PATH_SIZE, "%s/%s", udev_device_get_syspath(dev), attr_name); condlog(4, "open '%s'", devpath); - if (stat(devpath, &statbuf) != 0) { + /* read attribute value */ + fd = open(devpath, O_RDONLY); + if (fd < 0) { + condlog(4, "attribute '%s' can not be opened: %s", + devpath, strerror(errno)); + return -errno; + } + if (fstat(fd, &statbuf) != 0) { condlog(4, "stat '%s' failed: %s", devpath, strerror(errno)); + close(fd); return -ENXIO; } /* skip directories */ if (S_ISDIR(statbuf.st_mode)) { condlog(4, "%s is a directory", devpath); + close(fd); return -EISDIR; } /* skip non-writeable files */ if ((statbuf.st_mode & S_IRUSR) == 0) { condlog(4, "%s is not readable", devpath); + close(fd); return -EPERM; } - /* read attribute value */ - fd = open(devpath, O_RDONLY); - if (fd < 0) { - condlog(4, "attribute '%s' can not be opened: %s", - devpath, strerror(errno)); - return -errno; - } size = read(fd, value, value_len); if (size < 0) { condlog(4, "read from %s failed: %s", devpath, strerror(errno)); @@ -163,30 +167,33 @@ ssize_t sysfs_attr_set_value(struct udev_device *dev, const char *attr_name, snprintf(devpath, PATH_SIZE, "%s/%s", udev_device_get_syspath(dev), attr_name); condlog(4, "open '%s'", devpath); - if (stat(devpath, &statbuf) != 0) { + /* write attribute value */ + fd = open(devpath, O_WRONLY); + if (fd < 0) { + condlog(4, "attribute '%s' can not be opened: %s", + devpath, strerror(errno)); + return -errno; + } + if (fstat(fd, &statbuf) != 0) { condlog(4, "stat '%s' failed: %s", devpath, strerror(errno)); + close(fd); return -errno; } /* skip directories */ if (S_ISDIR(statbuf.st_mode)) { condlog(4, "%s is a directory", devpath); + close(fd); return -EISDIR; } /* skip non-writeable files */ if ((statbuf.st_mode & S_IWUSR) == 0) { condlog(4, "%s is not writeable", devpath); + close(fd); return -EPERM; } - /* write attribute value */ - fd = open(devpath, O_WRONLY); - if (fd < 0) { - condlog(4, "attribute '%s' can not be opened: %s", - devpath, strerror(errno)); - return -errno; - } size = write(fd, value, value_len); if (size < 0) { condlog(4, "write to %s failed: %s", devpath, strerror(errno)); -- 2.6.6 -- dm-devel mailing list [email protected] https://www.redhat.com/mailman/listinfo/dm-devel
