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