If the lock record doesn't match the expected record size we need

to seek to the end of the record as we otherwise may have gone too
far (or not far enough).  Fixes interop problems when the time stamp
record changes size.

diff --git a/plugins/sudoers/timestamp.c b/plugins/sudoers/timestamp.c
index b2f50e4722e5f60604713e3aca1d0a6c037f9897..3b7b8728fe4c15336aa53c661245fcb06eced55a 100644 (file)
--- a/plugins/sudoers/timestamp.c
+++ b/plugins/sudoers/timestamp.c
@@ -608,6 +608,14 @@ timestamp_lock(void *vcookie, struct passwd *pw)
        if (ts_write(cookie->fd, cookie->fname, &entry, 0) == -1)
            debug_return_bool(false);
     }
+    if (entry.size != sizeof(entry)) {
+       /* Reset position if the lock record has an unexpected size. */
+       if (lseek(cookie->fd, entry.size, SEEK_SET) == -1) {
+           sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO|SUDO_DEBUG_LINENO,
+               "unable to seek to %lld", (long long)entry.size);
+           debug_return_bool(false);
+       }
+    }
 
     /* Search for a tty/ppid-based record or append a new one. */
     sudo_debug_printf(SUDO_DEBUG_DEBUG|SUDO_DEBUG_LINENO,