linux-kernel - [RFC PATCH 1/5] signal: Teach sigsuspend to use set_user

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

Message-ID: <87ef45axa4.fsf_-_@xmission.com>
Date:   Fri, 07 Jun 2019 16:41:23 -0500
From:   ebiederm@...ssion.com (Eric W. Biederman)
To:     Oleg Nesterov <oleg@...hat.com>
Cc:     Andrew Morton <akpm@...ux-foundation.org>,
        Deepa Dinamani <deepa.kernel@...il.com>,
        linux-kernel@...r.kernel.org, arnd@...db.de, dbueso@...e.de,
        axboe@...nel.dk, dave@...olabs.net, e@...24.org, jbaron@...mai.com,
        linux-fsdevel@...r.kernel.org, linux-aio@...ck.org,
        omar.kilani@...il.com, tglx@...utronix.de,
        Al Viro <viro@...IV.linux.org.uk>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        David Laight <David.Laight@...LAB.COM>,
        <linux-arch@...r.kernel.org>
Subject: [RFC PATCH 1/5] signal: Teach sigsuspend to use set_user_sigmask


The sigsuspend system call overrides the signal mask just
like all of the other users of set_user_sigmask, so convert
it to use the same helpers.

Signed-off-by: "Eric W. Biederman" <ebiederm@...ssion.com>
---
 kernel/signal.c | 43 +++++++++++++++++++------------------------
 1 file changed, 19 insertions(+), 24 deletions(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index 6f72cff043f0..bfa36320a4f7 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2932,6 +2932,15 @@ int sigprocmask(int how, sigset_t *set, sigset_t *oldset)
 }
 EXPORT_SYMBOL(sigprocmask);
 
+static int set_sigmask(sigset_t *kmask)
+{
+	set_restore_sigmask();
+	current->saved_sigmask = current->blocked;
+	set_current_blocked(kmask);
+
+	return 0;
+}
+
 /*
  * The api helps set app-provided sigmasks.
  *
@@ -2952,11 +2961,7 @@ int set_user_sigmask(const sigset_t __user *umask, size_t sigsetsize)
 	if (copy_from_user(&kmask, umask, sizeof(sigset_t)))
 		return -EFAULT;
 
-	set_restore_sigmask();
-	current->saved_sigmask = current->blocked;
-	set_current_blocked(&kmask);
-
-	return 0;
+	return set_sigmask(&kmask);
 }
 
 #ifdef CONFIG_COMPAT
@@ -2972,11 +2977,7 @@ int set_compat_user_sigmask(const compat_sigset_t __user *umask,
 	if (get_compat_sigset(&kmask, umask))
 		return -EFAULT;
 
-	set_restore_sigmask();
-	current->saved_sigmask = current->blocked;
-	set_current_blocked(&kmask);
-
-	return 0;
+	return set_sigmask(&kmask);
 }
 #endif
 
@@ -4409,14 +4410,10 @@ SYSCALL_DEFINE0(pause)
 
 static int sigsuspend(sigset_t *set)
 {
-	current->saved_sigmask = current->blocked;
-	set_current_blocked(set);
-
 	while (!signal_pending(current)) {
 		__set_current_state(TASK_INTERRUPTIBLE);
 		schedule();
 	}
-	set_restore_sigmask();
 	return -ERESTARTNOHAND;
 }
 
@@ -4430,12 +4427,10 @@ SYSCALL_DEFINE2(rt_sigsuspend, sigset_t __user *, unewset, size_t, sigsetsize)
 {
 	sigset_t newset;
 
-	/* XXX: Don't preclude handling different sized sigset_t's.  */
-	if (sigsetsize != sizeof(sigset_t))
-		return -EINVAL;
-
-	if (copy_from_user(&newset, unewset, sizeof(newset)))
+	set_user_sigmask(unewset, sigsetsize);
+	if (!unewset)
 		return -EFAULT;
+
 	return sigsuspend(&newset);
 }
  
@@ -4444,12 +4439,10 @@ COMPAT_SYSCALL_DEFINE2(rt_sigsuspend, compat_sigset_t __user *, unewset, compat_
 {
 	sigset_t newset;
 
-	/* XXX: Don't preclude handling different sized sigset_t's.  */
-	if (sigsetsize != sizeof(sigset_t))
-		return -EINVAL;
-
-	if (get_compat_sigset(&newset, unewset))
+	set_compat_user_sigmask(unewset, sigsetsize);
+	if (!unewset)
 		return -EFAULT;
+
 	return sigsuspend(&newset);
 }
 #endif
@@ -4459,6 +4452,7 @@ SYSCALL_DEFINE1(sigsuspend, old_sigset_t, mask)
 {
 	sigset_t blocked;
 	siginitset(&blocked, mask);
+	set_sigmask(&blocked);
 	return sigsuspend(&blocked);
 }
 #endif
@@ -4467,6 +4461,7 @@ SYSCALL_DEFINE3(sigsuspend, int, unused1, int, unused2, old_sigset_t, mask)
 {
 	sigset_t blocked;
 	siginitset(&blocked, mask);
+	set_sigmask(&blocked);
 	return sigsuspend(&blocked);
 }
 #endif
-- 
2.21.0.dirty