From: Eric Biggers <ebiggers@xxxxxxxxxx>
As ext4 and f2fs do, ubifs should check for consistent encryption
contexts during ->lookup() in an encrypted directory. This protects
certain users of filesystem encryption against certain types of offline
attacks.
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
---
fs/ubifs/dir.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
index 30825d882aa9..bbe2b346a94f 100644
--- a/fs/ubifs/dir.c
+++ b/fs/ubifs/dir.c
@@ -285,6 +285,15 @@ static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry,
goto out_dent;
}
+ if (ubifs_crypt_is_encrypted(dir) &&
+ (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
+ !fscrypt_has_permitted_context(dir, inode)) {
+ ubifs_warn(c, "Inconsistent encryption contexts: %lu/%lu",
+ dir->i_ino, inode->i_ino);
+ err = -EPERM;
+ goto out_inode;
+ }
+
done:
kfree(dent);
fscrypt_free_filename(&nm);
@@ -295,6 +304,8 @@ static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry,
d_add(dentry, inode);
return NULL;
+out_inode:
+ iput(inode);
out_dent:
kfree(dent);
out_fname:
--
2.12.2.715.g7642488e1d-goog
