Fix: runas: less-than-zero comparison of an unsigned value

[lttng-tools.git] / src / common / runas.c

diff --git a/src/common/runas.c b/src/common/runas.c
index db95429b4a0a43ef13aaacf890c726c93e0ed79c..ab5fb589117597162369044d6e549f43efde2194 100644 (file)
--- a/src/common/runas.c
+++ b/src/common/runas.c
@@ -907,14 +907,15 @@ static int get_user_infos_from_uid(
 {
        int ret;
        char *buf = NULL;
-       size_t buf_size;
+       long raw_get_pw_buf_size;
+       size_t get_pw_buf_size;
        struct passwd pwd;
        struct passwd *result = NULL;
 
        /* Fetch the max size for the temporary buffer. */
        errno = 0;
-       buf_size = sysconf(_SC_GETPW_R_SIZE_MAX);
-       if (buf_size < 0) {
+       raw_get_pw_buf_size = sysconf(_SC_GETPW_R_SIZE_MAX);
+       if (raw_get_pw_buf_size < 0) {
                if (errno != 0) {
                        PERROR("Failed to query _SC_GETPW_R_SIZE_MAX");
                        goto error;
@@ -923,16 +924,18 @@ static int get_user_infos_from_uid(
                /* Limit is indeterminate. */
                WARN("Failed to query _SC_GETPW_R_SIZE_MAX as it is "
                        "indeterminate; falling back to default buffer size");
-               buf_size = GETPW_BUFFER_FALLBACK_SIZE;
+               raw_get_pw_buf_size = GETPW_BUFFER_FALLBACK_SIZE;
        }
 
-       buf = zmalloc(buf_size);
+       get_pw_buf_size = (size_t) raw_get_pw_buf_size;
+
+       buf = zmalloc(get_pw_buf_size);
        if (buf == NULL) {
                PERROR("Failed to allocate buffer to get password file entries");
                goto error;
        }
 
-       ret = getpwuid_r(uid, &pwd, buf, buf_size, &result);
+       ret = getpwuid_r(uid, &pwd, buf, get_pw_buf_size, &result);
        if (ret < 0) {
                PERROR("Failed to get user information for user:  uid = %d",
                                (int) uid);