Add io_log_read() and io_log_gets() to hide differences between

gzread/fread and gzgets/fgets.  Check for premature EOF and error
from io_log_read().  Also sanity check the index in the timing file.
Coverity CID 104630.

diff --git a/plugins/sudoers/sudoreplay.c b/plugins/sudoers/sudoreplay.c
index e512f11e93c66236122ccd7ccf7b7f54721ace12..54238d0595aee282cc2f6a96cbe95a2bcf2a4866 100644 (file)
--- a/plugins/sudoers/sudoreplay.c
+++ b/plugins/sudoers/sudoreplay.c
@@ -329,6 +329,44 @@ done:
     exit(exitcode);
 }
 
+/*
+ * Call gzread() or fread() for the I/O log file in question.
+ * Return 0 for EOF or -1 on error.
+ */
+static ssize_t
+io_log_read(int idx, char *buf, size_t nbytes)
+{
+    ssize_t nread;
+    debug_decl(io_log_read, SUDO_DEBUG_UTIL)
+
+    if (nbytes > INT_MAX) {
+       errno = EINVAL;
+       debug_return_ssize_t(-1);
+    }
+#ifdef HAVE_ZLIB_H
+    nread = gzread(io_log_files[idx].fd.g, buf, nbytes);
+#else
+    nread = (ssize_t)fread(buf, 1, nbytes, io_log_files[idx].fd.f);
+    if (nread == 0 && ferror(io_log_files[idx].fd.f))
+       nread = -1;
+#endif
+    debug_return_ssize_t(nread);
+}
+
+static char *
+io_log_gets(int idx, char *buf, size_t nbytes)
+{
+    char *str;
+    debug_decl(io_log_gets, SUDO_DEBUG_UTIL)
+
+#ifdef HAVE_ZLIB_H
+    str = gzgets(io_log_files[idx].fd.g, buf, nbytes);
+#else
+    str = fgets(buf, nbytes, io_log_files[idx].fd.f);
+#endif
+    debug_return_str(str);
+}
+
 static void
 replay_session(const double max_wait, const char *decimal)
 {
@@ -385,11 +423,7 @@ replay_session(const double max_wait, const char *decimal)
     /*
      * Read each line of the timing file, displaying the output streams.
      */
-#ifdef HAVE_ZLIB_H
-    while (gzgets(io_log_files[IOFD_TIMING].fd.g, buf, sizeof(buf)) != NULL) {
-#else
-    while (fgets(buf, sizeof(buf), io_log_files[IOFD_TIMING].fd.f) != NULL) {
-#endif
+    while (io_log_gets(IOFD_TIMING, buf, sizeof(buf)) != NULL) {
        size_t len, nbytes, nread;
        double seconds, to_wait;
        struct timeval timeout;
@@ -414,7 +448,7 @@ replay_session(const double max_wait, const char *decimal)
        sudo_ev_loop(evbase, 0);
 
        /* Even if we are not replaying, we still have to delay. */
-       if (io_log_files[idx].fd.v == NULL)
+       if (idx >= IOFD_MAX || io_log_files[idx].fd.v == NULL)
            continue;
 
        /* Check whether we need to convert newline to CR LF pairs. */
@@ -428,11 +462,18 @@ replay_session(const double max_wait, const char *decimal)
                len = sizeof(buf);
            else
                len = nbytes;
-#ifdef HAVE_ZLIB_H
-           nread = gzread(io_log_files[idx].fd.g, buf, len);
-#else
-           nread = fread(buf, 1, len, io_log_files[idx].fd.f);
-#endif
+           nread = io_log_read(idx, buf, len);
+           if (nread <= 0) {
+               if (nread == 0) {
+                   sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+                       "%s: premature EOF, expected %zu bytes",
+                       io_log_files[idx].suffix, nbytes);
+               } else {
+                   sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO|SUDO_DEBUG_LINENO,
+                       "%s: read error", io_log_files[idx].suffix);
+               }
+               break;
+           }
            nbytes -= nread;
 
            /* Convert newline to carriage return + linefeed if needed. */