From 446b4207cc7a30d8a4d5b2445a5a1b27d440f55d Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Fri, 18 Feb 2011 17:04:56 -0500 Subject: major improvements to temp file name generator use current time in nanoseconds and some potentially-random (if aslr is enabled) pointer values for the initial tempfile name generation, and step via a cheap linear prng on collisions. limit the number of retry attempts to prevent denial of service attacks even if an attacker can guess the filenames. --- src/temp/mkstemp.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'src/temp/mkstemp.c') diff --git a/src/temp/mkstemp.c b/src/temp/mkstemp.c index 34642569..2ab3020b 100644 --- a/src/temp/mkstemp.c +++ b/src/temp/mkstemp.c @@ -11,8 +11,8 @@ char *__mktemp(char *); int mkstemp(char *template) { - int fd; - for (;;) { + int fd, retries = 100; + while (retries--) { if (!__mktemp(template)) return 0; if ((fd = open(template, O_RDWR | O_CREAT | O_EXCL, 0600))>=0) return fd; @@ -21,6 +21,7 @@ int mkstemp(char *template) * that we have a valid template string */ strcpy(template+strlen(template)-6, "XXXXXX"); } + return -1; } LFS64(mkstemp); -- cgit v1.2.1