diff mbox

[v1,2/2] fuse: define the filesystem as untrusted

Message ID 1519053483-18396-3-git-send-email-zohar@linux.vnet.ibm.com (mailing list archive)
State New, archived
Headers show

Commit Message

Mimi Zohar Feb. 19, 2018, 3:18 p.m. UTC 
Files on FUSE can change at any point in time without IMA being able
to detect it.  The file data read for the file signature verification
could be totally different from what is subsequently read, making the
signature verification useless.

FUSE can be mounted by unprivileged users either today with fusermount
installed with setuid, or soon with the upcoming patches to allow FUSE
mounts in a non-init user namespace.

This patch sets the SB_I_IMA_UNTRUSTED_FS flag.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Seth Forshee <seth.forshee@canonical.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Dongsu Park <dongsu@kinvolk.io>
Cc: Alban Crequy <alban@kinvolk.io>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
---
 fs/fuse/inode.c | 1 +
 1 file changed, 1 insertion(+)
diff mbox

Patch

diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 624f18bbfd2b..2cbf01fc85a2 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -1080,6 +1080,7 @@  static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_maxbytes = MAX_LFS_FILESIZE;
 	sb->s_time_gran = 1;
 	sb->s_export_op = &fuse_export_operations;
+	sb->s_iflags |= SB_I_IMA_UNTRUSTED_FS;
 
 	file = fget(d.fd);
 	err = -EINVAL;