linux-kernel - [PATCH] sigwait eats blocked default-ignore signals

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20071112234155.783744D04C9@magilla.localdomain>
Date:	Mon, 12 Nov 2007 15:41:55 -0800 (PST)
From:	Roland McGrath <roland@...hat.com>
To:	Linus Torvalds <torvalds@...ux-foundation.org>,
	Andrew Morton <akpm@...ux-foundation.org>
Cc:	Oleg Nesterov <oleg@...sign.ru>
Subject: [PATCH] sigwait eats blocked default-ignore signals

cf http://bugzilla.kernel.org/show_bug.cgi?id=9347

While a signal is blocked, it must be posted even if its action is
SIG_IGN or is SIG_DFL with the default action to ignore.  This works
right most of the time, but is broken when a sigwait (rt_sigtimedwait)
is in progress.  This changes the early-discard check to respect
real_blocked.  ~blocked is the set to check for "should wake up now",
but ~(blocked|real_blocked) is the set for "blocked" semantics as
defined by POSIX.

Signed-off-by: Roland McGrath <roland@...hat.com>
---
 kernel/signal.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index 0ac614a..9b22790 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -55,7 +55,7 @@ static int sig_ignored(struct task_struct *t, int sig)
 	 * signal handler may change by the time it is
 	 * unblocked.
 	 */
-	if (sigismember(&t->blocked, sig))
+	if (sigismember(&t->blocked, sig) || sigismember(&t->real_blocked, sig))
 		return 0;

 	/* Is it explicitly or implicitly ignored? */
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/