From 8a5c56c2bdbcc856ab38b494a3ab58cc16d07e9b Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers@google.com>
Date: Thu, 1 Jul 2021 23:53:49 -0700
Subject: [PATCH] ubifs: report correct st_size for encrypted symlinks
commit 064c734986011390b4d111f1a99372b7f26c3850 upstream.
The stat() family of syscalls report the wrong size for encrypted
symlinks, which has caused breakage in several userspace programs.
Fix this by calling fscrypt_symlink_getattr() after ubifs_getattr() for
encrypted symlinks. This function computes the correct size by reading
and decrypting the symlink target (if it's not already cached).
For more details, see the commit which added fscrypt_symlink_getattr().
Fixes: ca7f85be8d6c ("ubifs: Add support for encrypted symlinks")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210702065350.209646-5-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/ubifs/file.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index 2e4e1d1599693..5cfa28cd00cdc 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -1630,6 +1630,17 @@ static const char *ubifs_get_link(struct dentry *dentry,
return fscrypt_get_symlink(inode, ui->data, ui->data_len, done);
}
+static int ubifs_symlink_getattr(struct user_namespace *mnt_userns,
+ const struct path *path, struct kstat *stat,
+ u32 request_mask, unsigned int query_flags)
+{
+ ubifs_getattr(mnt_userns, path, stat, request_mask, query_flags);
+
+ if (IS_ENCRYPTED(d_inode(path->dentry)))
+ return fscrypt_symlink_getattr(path, stat);
+ return 0;
+}
+
const struct address_space_operations ubifs_file_address_operations = {
.readpage = ubifs_readpage,
.writepage = ubifs_writepage,
@@ -1655,7 +1666,7 @@ const struct inode_operations ubifs_file_inode_operations = {
const struct inode_operations ubifs_symlink_inode_operations = {
.get_link = ubifs_get_link,
.setattr = ubifs_setattr,
- .getattr = ubifs_getattr,
+ .getattr = ubifs_symlink_getattr,
.listxattr = ubifs_listxattr,
.update_time = ubifs_update_time,
};