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From: Michal Suchanek <msuchanek@suse.de>
To: linux-kernel@vger.kernel.org
Cc: Michal Suchanek <msuchanek@suse.de>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	Matthew Garrett <matthewgarrett@google.com>,
	James Morris <jmorris@namei.org>,
	David Howells <dhowells@redhat.com>,
	Andy Shevchenko <andy.shevchenko@gmail.com>,
	acpi4asus-user@lists.sourceforge.net,
	platform-driver-x86@vger.kernel.org,
	Thomas Gleixner <tglx@linutronix.de>, Greg KH <greg@kroah.com>
Subject: [PATCH] debugfs: lockdown: Allow reading debugfs files that are not world readable
Date: Tue,  4 Jan 2022 18:05:05 +0100	[thread overview]
Message-ID: <20220104170505.10248-1-msuchanek@suse.de> (raw)


When the kernel is locked down the kernel allows reading only debugfs
files with mode 444. Mode 400 is also valid but is not allowed.

Make the 444 into a mask.

Fixes: 5496197f9b08 ("debugfs: Restrict debugfs when the kernel is locked down")
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
---
 fs/debugfs/file.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index 7d162b0efbf0..950c63fa4d0b 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -147,7 +147,7 @@ static int debugfs_locked_down(struct inode *inode,
 			       struct file *filp,
 			       const struct file_operations *real_fops)
 {
-	if ((inode->i_mode & 07777) == 0444 &&
+	if ((inode->i_mode & 07777 & ~0444) == 0 &&
 	    !(filp->f_mode & FMODE_WRITE) &&
 	    !real_fops->unlocked_ioctl &&
 	    !real_fops->compat_ioctl &&
-- 
2.31.1


             reply	other threads:[~2022-01-04 17:05 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-04 17:05 Michal Suchanek [this message]
2022-01-05 11:51 ` [PATCH] debugfs: lockdown: Allow reading debugfs files that are not world readable Greg Kroah-Hartman
2022-01-05 13:12   ` Michal Suchánek
2022-01-06 14:48     ` Greg Kroah-Hartman

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