From 18df1cc77c20acf0d80cc5c5ef38afa2f3fa148e Mon Sep 17 00:00:00 2001 From: Ruediger Meier Date: Wed, 11 Jun 2014 17:31:56 +0200 Subject: utmpdump: fix localtime() error handling If current TZ has no representation of a given time_t then localtime() would return NULL and break the next strftime(). In practice this happens very likely on systems with 64bit time_t when parsing broken binary data. Seen on aarch64 (and probably s390) using our (incompatible) test wtmp data. Signed-off-by: Ruediger Meier --- login-utils/utmpdump.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/login-utils/utmpdump.c b/login-utils/utmpdump.c index 7611c9f0a..e1fefc63e 100644 --- a/login-utils/utmpdump.c +++ b/login-utils/utmpdump.c @@ -48,9 +48,10 @@ static char *timetostr(const time_t time) { static char s[29]; /* [Sun Sep 01 00:00:00 1998 PST] */ + struct tm *tmp; - if (time != 0) - strftime(s, 29, "%a %b %d %T %Y %Z", localtime(&time)); + if (time != 0 && (tmp = localtime(&time))) + strftime(s, 29, "%a %b %d %T %Y %Z", tmp); else s[0] = '\0'; -- cgit v1.2.3-55-g7522