Update Linux to v5.4.148
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz
Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c
index bb3b7fc..82575cf 100644
--- a/fs/crypto/hooks.c
+++ b/fs/crypto/hooks.c
@@ -58,8 +58,8 @@
if (err)
return err;
- /* ... in case we looked up ciphertext name before key was added */
- if (dentry->d_flags & DCACHE_ENCRYPTED_NAME)
+ /* ... in case we looked up no-key name before key was added */
+ if (fscrypt_is_nokey_name(dentry))
return -ENOKEY;
if (!fscrypt_has_permitted_context(dir, inode))
@@ -83,9 +83,9 @@
if (err)
return err;
- /* ... in case we looked up ciphertext name(s) before key was added */
- if ((old_dentry->d_flags | new_dentry->d_flags) &
- DCACHE_ENCRYPTED_NAME)
+ /* ... in case we looked up no-key name(s) before key was added */
+ if (fscrypt_is_nokey_name(old_dentry) ||
+ fscrypt_is_nokey_name(new_dentry))
return -ENOKEY;
if (old_dir != new_dir) {
@@ -305,3 +305,47 @@
return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(fscrypt_get_symlink);
+
+/**
+ * fscrypt_symlink_getattr() - set the correct st_size for encrypted symlinks
+ * @path: the path for the encrypted symlink being queried
+ * @stat: the struct being filled with the symlink's attributes
+ *
+ * Override st_size of encrypted symlinks to be the length of the decrypted
+ * symlink target (or the no-key encoded symlink target, if the key is
+ * unavailable) rather than the length of the encrypted symlink target. This is
+ * necessary for st_size to match the symlink target that userspace actually
+ * sees. POSIX requires this, and some userspace programs depend on it.
+ *
+ * This requires reading the symlink target from disk if needed, setting up the
+ * inode's encryption key if possible, and then decrypting or encoding the
+ * symlink target. This makes lstat() more heavyweight than is normally the
+ * case. However, decrypted symlink targets will be cached in ->i_link, so
+ * usually the symlink won't have to be read and decrypted again later if/when
+ * it is actually followed, readlink() is called, or lstat() is called again.
+ *
+ * Return: 0 on success, -errno on failure
+ */
+int fscrypt_symlink_getattr(const struct path *path, struct kstat *stat)
+{
+ struct dentry *dentry = path->dentry;
+ struct inode *inode = d_inode(dentry);
+ const char *link;
+ DEFINE_DELAYED_CALL(done);
+
+ /*
+ * To get the symlink target that userspace will see (whether it's the
+ * decrypted target or the no-key encoded target), we can just get it in
+ * the same way the VFS does during path resolution and readlink().
+ */
+ link = READ_ONCE(inode->i_link);
+ if (!link) {
+ link = inode->i_op->get_link(dentry, inode, &done);
+ if (IS_ERR(link))
+ return PTR_ERR(link);
+ }
+ stat->size = strlen(link);
+ do_delayed_call(&done);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(fscrypt_symlink_getattr);