This is a note to let you know that I've just added the patch titled fs, fscrypt: clear DCACHE_ENCRYPTED_NAME when unaliasing directory to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: fs-fscrypt-clear-dcache_encrypted_name-when-unaliasing-directory.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Sun Nov 1 11:35:18 AM CET 2020 From: Eric Biggers <ebiggers@xxxxxxxxxx> Date: Sat, 31 Oct 2020 15:05:51 -0700 Subject: fs, fscrypt: clear DCACHE_ENCRYPTED_NAME when unaliasing directory To: stable@xxxxxxxxxxxxxxx Cc: linux-fscrypt@xxxxxxxxxxxxxxx, linux-ext4@xxxxxxxxxxxxxxx, linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx, linux-mtd@xxxxxxxxxxxxxxxxxxx, Sarthak Kukreti <sarthakkukreti@xxxxxxxxxxxx>, Theodore Ts'o <tytso@xxxxxxx> Message-ID: <20201031220553.1085782-4-ebiggers@xxxxxxxxxx> From: Eric Biggers <ebiggers@xxxxxxxxxx> commit 0bf3d5c1604ecbbd4e49e9f5b3c79152b87adb0d upstream. Make __d_move() clear DCACHE_ENCRYPTED_NAME on the source dentry. This is needed for when d_splice_alias() moves a directory's encrypted alias to its decrypted alias as a result of the encryption key being added. Otherwise, the decrypted alias will incorrectly be invalidated on the next lookup, causing problems such as unmounting a mount the user just mount()ed there. Note that we don't have to support arbitrary moves of this flag because fscrypt doesn't allow dentries with DCACHE_ENCRYPTED_NAME to be the source or target of a rename(). Fixes: 28b4c263961c ("ext4 crypto: revalidate dentry after adding or removing the key") Reported-by: Sarthak Kukreti <sarthakkukreti@xxxxxxxxxxxx> Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx> Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/dcache.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) --- a/fs/dcache.c +++ b/fs/dcache.c @@ -2713,6 +2713,20 @@ static void copy_name(struct dentry *den } /* + * When d_splice_alias() moves a directory's encrypted alias to its decrypted + * alias as a result of the encryption key being added, DCACHE_ENCRYPTED_NAME + * must be cleared. Note that we don't have to support arbitrary moves of this + * flag because fscrypt doesn't allow encrypted aliases to be the source or + * target of a rename(). + */ +static inline void fscrypt_handle_d_move(struct dentry *dentry) +{ +#if IS_ENABLED(CONFIG_FS_ENCRYPTION) + dentry->d_flags &= ~DCACHE_ENCRYPTED_NAME; +#endif +} + +/* * __d_move - move a dentry * @dentry: entry to move * @target: new dentry @@ -2787,6 +2801,7 @@ static void __d_move(struct dentry *dent list_move(&dentry->d_child, &dentry->d_parent->d_subdirs); __d_rehash(dentry); fsnotify_update_flags(dentry); + fscrypt_handle_d_move(dentry); write_seqcount_end(&target->d_seq); write_seqcount_end(&dentry->d_seq); Patches currently in stable-queue which might be from ebiggers@xxxxxxxxxx are queue-4.19/fscrypt-only-set-dentry_operations-on-ciphertext-dentries.patch queue-4.19/fscrypt-clean-up-and-improve-dentry-revalidation.patch queue-4.19/fscrypt-fix-race-allowing-rename-and-link-of-ciphertext-dentries.patch queue-4.19/fs-fscrypt-clear-dcache_encrypted_name-when-unaliasing-directory.patch queue-4.19/fscrypt-fix-race-where-lookup-marks-plaintext-dentry-as-ciphertext.patch