linux-kernel - [PATCH 3.16.y-ckt 073/165] eCryptfs: don't pass fs-specific ioctl commands through

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: <1427292138-7021-74-git-send-email-luis.henriques@canonical.com>
Date:	Wed, 25 Mar 2015 14:00:46 +0000
From:	Luis Henriques <luis.henriques@...onical.com>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	kernel-team@...ts.ubuntu.com
Cc:	Tyler Hicks <tyhicks@...onical.com>,
	Rocko <rockorequin@...mail.com>,
	Colin Ian King <colin.king@...onical.com>,
	Luis Henriques <luis.henriques@...onical.com>
Subject: [PATCH 3.16.y-ckt 073/165] eCryptfs: don't pass fs-specific ioctl commands through

3.16.7-ckt9 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Tyler Hicks <tyhicks@...onical.com>

commit 6d65261a09adaa374c05de807f73a144d783669e upstream.

eCryptfs can't be aware of what to expect when after passing an
arbitrary ioctl command through to the lower filesystem. The ioctl
command may trigger an action in the lower filesystem that is
incompatible with eCryptfs.

One specific example is when one attempts to use the Btrfs clone
ioctl command when the source file is in the Btrfs filesystem that
eCryptfs is mounted on top of and the destination fd is from a new file
created in the eCryptfs mount. The ioctl syscall incorrectly returns
success because the command is passed down to Btrfs which thinks that it
was able to do the clone operation. However, the result is an empty
eCryptfs file.

This patch allows the trim, {g,s}etflags, and {g,s}etversion ioctl
commands through and then copies up the inode metadata from the lower
inode to the eCryptfs inode to catch any changes made to the lower
inode's metadata. Those five ioctl commands are mostly common across all
filesystems but the whitelist may need to be further pruned in the
future.

https://bugzilla.kernel.org/show_bug.cgi?id=93691
https://launchpad.net/bugs/1305335

Signed-off-by: Tyler Hicks <tyhicks@...onical.com>
Cc: Rocko <rockorequin@...mail.com>
Cc: Colin Ian King <colin.king@...onical.com>
Signed-off-by: Luis Henriques <luis.henriques@...onical.com>
---
 fs/ecryptfs/file.c | 34 ++++++++++++++++++++++++++++++----
 1 file changed, 30 insertions(+), 4 deletions(-)

diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index de1111457b5e..0682699519af 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -303,9 +303,22 @@ ecryptfs_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	struct file *lower_file = ecryptfs_file_to_lower(file);
 	long rc = -ENOTTY;
 
-	if (lower_file->f_op->unlocked_ioctl)
+	if (!lower_file->f_op->unlocked_ioctl)
+		return rc;
+
+	switch (cmd) {
+	case FITRIM:
+	case FS_IOC_GETFLAGS:
+	case FS_IOC_SETFLAGS:
+	case FS_IOC_GETVERSION:
+	case FS_IOC_SETVERSION:
 		rc = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg);
-	return rc;
+		fsstack_copy_attr_all(file_inode(file), file_inode(lower_file));
+
+		return rc;
+	default:
+		return rc;
+	}
 }
 
 #ifdef CONFIG_COMPAT
@@ -315,9 +328,22 @@ ecryptfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 	struct file *lower_file = ecryptfs_file_to_lower(file);
 	long rc = -ENOIOCTLCMD;
 
-	if (lower_file->f_op->compat_ioctl)
+	if (!lower_file->f_op->compat_ioctl)
+		return rc;
+
+	switch (cmd) {
+	case FITRIM:
+	case FS_IOC32_GETFLAGS:
+	case FS_IOC32_SETFLAGS:
+	case FS_IOC32_GETVERSION:
+	case FS_IOC32_SETVERSION:
 		rc = lower_file->f_op->compat_ioctl(lower_file, cmd, arg);
-	return rc;
+		fsstack_copy_attr_all(file_inode(file), file_inode(lower_file));
+
+		return rc;
+	default:
+		return rc;
+	}
 }
 #endif
 
--
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/