From f98c5f53d4661ec22097d36f5debd195491ec3c6 Mon Sep 17 00:00:00 2001 From: Karel Zak Date: Thu, 15 Dec 2016 14:40:26 +0100 Subject: [PATCH 101/116] more: avoid double free() on exit On 'q' command more(1) calls end_it() function with _exit(). The _exit() may suspend program execution due to pending I/O on very loaded server. In this time SIGINT may be delivered due to impatient user who will press ^C. And then end_it() cleanup function may be executed by signal handler too. The result is double free()... Upstream: https://github.com/karelzak/util-linux/commit/0ed2a954714992938b35893b70197090a61b3b2e Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=1403971 Signed-off-by: Karel Zak --- text-utils/more.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/text-utils/more.c b/text-utils/more.c index 0e9c2bd..f98cb14 100644 --- a/text-utils/more.c +++ b/text-utils/more.c @@ -763,6 +763,14 @@ void chgwinsz(int dummy __attribute__((__unused__))) /* Clean up terminal state and exit. Also come here if interrupt signal received */ void __attribute__((__noreturn__)) end_it(int dummy __attribute__((__unused__))) { + /* May be executed as a signal handler as well as by main process. + * + * The _exit() may wait for pending I/O for really long time, be sure + * that signal handler is not executed in this time to avoid double + * de-initialization (free() calls, etc.). + */ + signal(SIGINT, SIG_IGN); + reset_tty(); if (clreol) { putchar('\r'); -- 2.9.3