The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 064c734986011390b4d111f1a99372b7f26c3850 Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers@xxxxxxxxxx>
Date: Thu, 1 Jul 2021 23:53:49 -0700
Subject: [PATCH] ubifs: report correct st_size for encrypted symlinks
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@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20210702065350.209646-5-ebiggers@xxxxxxxxxx
Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index 2e4e1d159969..5cfa28cd00cd 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,
};
