linux-kernel - [PATCH] SELinux: Always allow FIOCLEX and FIONCLEX

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: <4df50e95-6173-4ed1-9d08-3c1c4abab23f@gmail.com>
Date:   Tue, 25 Jan 2022 16:34:12 -0500
From:   Demi Marie Obenour <demiobenour@...il.com>
To:     Paul Moore <paul@...l-moore.com>,
        Stephen Smalley <stephen.smalley.work@...il.com>,
        Eric Paris <eparis@...isplace.org>
Cc:     Demi Marie Obenour <demiobenour@...il.com>,
        selinux@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] SELinux: Always allow FIOCLEX and FIONCLEX

These ioctls are equivalent to fcntl(fd, F_SETFD, flags), which SELinux
always allows too.  Furthermore, a failed FIOCLEX could result in a file
descriptor being leaked to a process that should not have access to it.

Signed-off-by: Demi Marie Obenour <demiobenour@...il.com>
---
 security/selinux/hooks.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 5b6895e4fc29..8f3b2f15c1f3 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3728,6 +3728,11 @@ static int selinux_file_ioctl(struct file *file, unsigned int cmd,
 		error = file_has_perm(cred, file, FILE__GETATTR);
 		break;
 
+	/* must always succeed */
+	case FIOCLEX:
+	case FIONCLEX:
+		break;
+
 	case FS_IOC_SETFLAGS:
 	case FS_IOC_SETVERSION:
 		error = file_has_perm(cred, file, FILE__SETATTR);
-- 
Sincerely,
Demi Marie Obenour