Fix: always check return value of unlink()

Resolves:
https://fedorahosted.org/sssd/ticket/2506

Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

4 files changed, 38 insertions, 7 deletions

diff --git a/src/monitor/monitor.c b/src/monitor/monitor.c
index b55757d95..c6834a115 100644
--- a/src/monitor/monitor.c
+++ b/src/monitor/monitor.c
@@ -1685,7 +1685,14 @@ static errno_t load_configuration(TALLOC_CTX *mem_ctx,
          * misconfiguration gets in the way
          */
         talloc_zfree(ctx->cdb);
-        unlink(cdb_file);
+        ret = unlink(cdb_file);
+        if (ret != EOK && errno != ENOENT) {
+            ret = errno;
+            DEBUG(SSSDBG_MINOR_FAILURE,
+                  "Purging existing confdb failed: %d [%s].\n",
+                  ret, sss_strerror(ret));
+            goto done;
+        }
 
         ret = confdb_init(ctx, &ctx->cdb, cdb_file);
         if (ret != EOK) {
diff --git a/src/responder/ssh/sshsrv_cmd.c b/src/responder/ssh/sshsrv_cmd.c
index 5bed2e0ad..e7bed3ab2 100644
--- a/src/responder/ssh/sshsrv_cmd.c
+++ b/src/responder/ssh/sshsrv_cmd.c
@@ -536,7 +536,7 @@ static errno_t
 ssh_host_pubkeys_update_known_hosts(struct ssh_cmd_ctx *cmd_ctx)
 {
     TALLOC_CTX *tmp_ctx;
-    errno_t ret;
+    errno_t ret, tmp_ret;
     const char *attrs[] = {
         SYSDB_NAME,
         SYSDB_NAME_ALIAS,
@@ -654,7 +654,17 @@ ssh_host_pubkeys_update_known_hosts(struct ssh_cmd_ctx *cmd_ctx)
 
 done:
     if (fd != -1) close(fd);
-    if (ret != EOK && filename) unlink(filename);
+    if (ret != EOK && filename) {
+        tmp_ret = unlink(filename);
+        /* non-fatal failure */
+        if (tmp_ret != EOK) {
+            tmp_ret = errno;
+            DEBUG(SSSDBG_MINOR_FAILURE,
+                  "Failed to remove file: %s - %d : [%s]!\n",
+                  filename, tmp_ret, sss_strerror(tmp_ret));
+        }
+    }
+
     talloc_free(tmp_ctx);
 
     return ret;
diff --git a/src/sbus/sssd_dbus_server.c b/src/sbus/sssd_dbus_server.c
index 18fb98df6..137524892 100644
--- a/src/sbus/sssd_dbus_server.c
+++ b/src/sbus/sssd_dbus_server.c
@@ -192,7 +192,7 @@ int sbus_new_server(TALLOC_CTX *mem_ctx,
     DBusError dbus_error;
     dbus_bool_t dbret;
     char *tmp;
-    int ret;
+    int ret, tmp_ret;
     char *filename;
     char *symlink_filename = NULL;
     const char *socket_address;
@@ -343,9 +343,17 @@ int sbus_new_server(TALLOC_CTX *mem_ctx,
 
     *_server = talloc_steal(mem_ctx, server);
     ret = EOK;
+
 done:
     if (ret != EOK && symlink_filename) {
-        unlink(symlink_filename);
+        tmp_ret = unlink(symlink_filename);
+        /* non-fatal failure */
+        if (tmp_ret != EOK) {
+            tmp_ret = errno;
+            DEBUG(SSSDBG_MINOR_FAILURE,
+                  "Failed to remove symbolic link: %d [%s]!\n",
+                  tmp_ret, sss_strerror(tmp_ret));
+        }
     }
     talloc_free(tmp_ctx);
     return ret;
diff --git a/src/util/server.c b/src/util/server.c
index 03f4b9588..abd29310f 100644
--- a/src/util/server.c
+++ b/src/util/server.c
@@ -194,8 +194,14 @@ int pidfile(const char *path, const char *name)
 
         /* nothing in the file or no process */
         close(fd);
-        unlink(file);
-
+        ret = unlink(file);
+        /* non-fatal failure */
+        if (ret != EOK) {
+            ret = errno;
+            DEBUG(SSSDBG_MINOR_FAILURE,
+                  "Failed to remove file: %s - %d [%s]!\n",
+                  file, ret, sss_strerror(ret));
+        }
     } else {
         if (err != ENOENT) {
             talloc_free(file);