| Message ID | 1482174948-104602-1-git-send-email-ebiggers3@gmail.com |
|---|---|
| State | Accepted |
| Headers | show |
On 19.12.2016 20:15, Eric Biggers wrote: > From: Eric Biggers <ebiggers@google.com> > > In several places, ubifs checked for an encryption key before creating a > file in an encrypted directory. This was redundant with > fscrypt_setup_filename() or ubifs_new_inode(), and in the case of > ubifs_link() it broke linking to special files. So remove the extra > checks. Thanks for doing this. I assume same or similar changes were also needed for f2fs and ext4 since I've duplicated the logic from them? :-) Thanks, //richard
On Mon, Dec 19, 2016 at 08:59:15PM +0100, Richard Weinberger wrote: > On 19.12.2016 20:15, Eric Biggers wrote: > > From: Eric Biggers <ebiggers@google.com> > > > > In several places, ubifs checked for an encryption key before creating a > > file in an encrypted directory. This was redundant with > > fscrypt_setup_filename() or ubifs_new_inode(), and in the case of > > ubifs_link() it broke linking to special files. So remove the extra > > checks. > > Thanks for doing this. I assume same or similar changes were also needed > for f2fs and ext4 since I've duplicated the logic from them? :-) > Well all the filesystems are a little different, but I checked link, create, mkdir, mknod, symlink, and tmpfile. UBIFS generally seemed to be the odd one out with regards to having these extra checks: ext4_link(): relies on check in fscrypt_setup_filename() ext4_create(): relies on check in __ext4_new_inode() ext4_mkdir(): relies on check in __ext4_new_inode() ext4_mknod(): relies on check in __ext4_new_inode() ext4_symlink(): relies on __ext4_new_inode() preloading encryption info of new inode ext4_tmpfile(): relies on check in __ext4_new_inode() f2fs_link(): relies on check in fscrypt_setup_filename() f2fs_create(): relies on check in fscrypt_setup_filename() f2fs_mkdir(): relies on check in fscrypt_setup_filename() f2fs_mknod(): relies on check in fscrypt_setup_filename() f2fs_symlink(): has an explicit call to fscrypt_get_encryption_info() because f2fs_new_inode() doesn't preload encryption info of new inode. Check of fscrypt_has_encryption_key() appears unnecessary. f2fs_tmpfile(): has an explicit load of encryption key with no check; it's unclear whether this is sufficient, since it never calls fscrypt_setup_filename() So I am wondering why ext4 "preloads" encryption keys of new inodes but f2fs doesn't, and whether f2fs_tmpfile() is doing the correct checks. But neither fs had all the redundant checks this patch removes from ubifs. Eric
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index 9de9eaa..d346f1e 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -400,16 +400,6 @@ static int do_tmpfile(struct inode *dir, struct dentry *dentry, dbg_gen("dent '%pd', mode %#hx in dir ino %lu", dentry, mode, dir->i_ino); - if (ubifs_crypt_is_encrypted(dir)) { - err = fscrypt_get_encryption_info(dir); - if (err) - return err; - - if (!fscrypt_has_encryption_key(dir)) { - return -EPERM; - } - } - err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm); if (err) return err; @@ -751,17 +741,9 @@ static int ubifs_link(struct dentry *old_dentry, struct inode *dir, ubifs_assert(inode_is_locked(dir)); ubifs_assert(inode_is_locked(inode)); - if (ubifs_crypt_is_encrypted(dir)) { - if (!fscrypt_has_permitted_context(dir, inode)) - return -EPERM; - - err = fscrypt_get_encryption_info(inode); - if (err) - return err; - - if (!fscrypt_has_encryption_key(inode)) - return -EPERM; - } + if (ubifs_crypt_is_encrypted(dir) && + !fscrypt_has_permitted_context(dir, inode)) + return -EPERM; err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm); if (err) @@ -1010,17 +992,6 @@ static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) if (err) return err; - if (ubifs_crypt_is_encrypted(dir)) { - err = fscrypt_get_encryption_info(dir); - if (err) - goto out_budg; - - if (!fscrypt_has_encryption_key(dir)) { - err = -EPERM; - goto out_budg; - } - } - err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm); if (err) goto out_budg; @@ -1106,17 +1077,6 @@ static int ubifs_mknod(struct inode *dir, struct dentry *dentry, return err; } - if (ubifs_crypt_is_encrypted(dir)) { - err = fscrypt_get_encryption_info(dir); - if (err) - goto out_budg; - - if (!fscrypt_has_encryption_key(dir)) { - err = -EPERM; - goto out_budg; - } - } - err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm); if (err) goto out_budg; @@ -1241,18 +1201,6 @@ static int ubifs_symlink(struct inode *dir, struct dentry *dentry, goto out_inode; } - err = fscrypt_get_encryption_info(inode); - if (err) { - kfree(sd); - goto out_inode; - } - - if (!fscrypt_has_encryption_key(inode)) { - kfree(sd); - err = -EPERM; - goto out_inode; - } - ostr.name = sd->encrypted_path; ostr.len = disk_link.len;