[RFC v2 3/4] ext4: add verifier check for symlink with append/immutable flags
flat view
From: "Luis R. Rodriguez" <mcgrof@kernel.org>
Date: 2018-05-10 23:14:08
Also in:
linux-btrfs, linux-ext4, linux-fsdevel, linux-xfs, lkml
Subsystem:
ext4 file system, filesystems (vfs and infrastructure), the rest · Maintainers:
"Theodore Ts'o", Alexander Viro, Christian Brauner, Linus Torvalds
The Linux VFS does not allow a way to set append/immuttable attributes to symlinks, this is just not possible. If this is detected inform the user as the filesystem must be corrupted. Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org> --- fs/ext4/inode.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 37a2f7a2b66a..6acf0dd6b6e6 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c@@ -4947,6 +4947,13 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino) inode->i_op = &ext4_dir_inode_operations; inode->i_fop = &ext4_dir_operations; } else if (S_ISLNK(inode->i_mode)) { + /* VFS does not allow setting these so must be corruption */ + if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) { + EXT4_ERROR_INODE(inode, + "immutable or append flags not allowed on symlinks"); + ret = -EFSCORRUPTED; + goto bad_inode; + } if (ext4_encrypted_inode(inode)) { inode->i_op = &ext4_encrypted_symlink_inode_operations; ext4_set_aops(inode);
--
2.17.0