From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 96C6F480DCF; Tue, 25 Aug 2026 13:41:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787665313; cv=none; b=pGNsaF6wWIn5JXmdH45pQUtYxKjJzyPUKGsfbBqzUJPGbGd8CiHidcOWbMbryr3zp41ZgT3cm8uoInorSnIHtZyeG5tz8nuo1ClOZ3exory585oNf7qpoBgOSFgVLPOfe2mDyVU0ToRB1sCBHHOSglxwRBKShnGV1Sp60giR9x4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787665313; c=relaxed/simple; bh=9znMyG8X4+qdxKuGE9wvXWrGyxLmzIAveCYMxZOTxv8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SGpB34xouFPoBM2xhXB2Ebyc/5QB1cak9alix5eYBvsk8HExJDfQK24ipyGPsVgL2rQYAXWVO6qhZs/W724mUNknVIrOaBxHntbs4jSIo0Qh0kYMZ2HoHznCWA+MUjnxrHBSL8iQ2HGyAp81ppWLBcAHVv/iTNILTA3fdFxTF0Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=a1ZQe4bi; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="a1ZQe4bi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ED27F1F000E9; Tue, 25 Aug 2026 13:41:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787665311; bh=LJAFBWe+JNw9W2I/4OUbfQZk7QwTvqsxhpcRX6q+5oY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=a1ZQe4biKkFVgj7bA0KY1sNoQpZ1UaoEDT7/ktVyGmHw5PXjtp62hk1obRfulj4b5 t6FhB4j2EQFTu3ciZ8+32ku3Hpq30vUD+zMxiA6PK1r4QNbbO0ypONsBcFYiV0+HoR 7YsGufeR2MN4vhFSKpof/Ce0mpeVNzvTEHjRCRmI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Disha Goel , Ojaswin Mujoo , Eric Biggers , Jan Kara , Theodore Tso Subject: [PATCH 6.18 30/94] ext4: dont enable DAX on new encrypted files Date: Tue, 25 Aug 2026 15:25:26 +0200 Message-ID: <20260825132543.087706100@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260825132541.887883084@linuxfoundation.org> References: <20260825132541.887883084@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Biggers commit da32af420d6d466e247c43ac0b829edeac7ae0ad upstream. Currently, when a new encrypted regular file is created, the call to ext4_set_inode_flags(inode, init=true) in __ext4_new_inode() is made before EXT4_INODE_ENCRYPT is set. As a result, it can set S_DAX if the filesystem is mounted with "-o dax=always". EXT4_INODE_ENCRYPT then actually gets set a bit later in __ext4_new_inode(), when it calls fscrypt_set_context() which calls ext4_set_context(). ext4_set_context() sets EXT4_INODE_ENCRYPT and calls ext4_set_inode_flags(inode, init=false) to set S_ENCRYPTED too. This was intended to clear S_DAX as well. However, this was broken by commit 043546e46dc7 ("fs/ext4: Only change S_DAX on inode load"). This causes data written to the file to bypass encryption, also causing xfstests failures such as generic/548 (when "-o dax=always" is used). Fix this by simplifying the flow by making __ext4_new_inode() set EXT4_INODE_ENCRYPT earlier. This makes it take effect in ext4_set_inode_flags(inode, init=true), making S_DAX never be set. Similarly, make EXT4_STATE_MAY_INLINE_DATA never be set in the first place on new encrypted inodes. Then it doesn't need to be cleared. As a result of these simplifications, ext4_set_context() no longer needs to change inode flags or state when 'handle != NULL'. Remove that too. Reported-by: Disha Goel Reported-by: Ojaswin Mujoo Closes: https://lore.kernel.org/r/20260723085648.1500357-1-ojaswin@linux.ibm.com Fixes: 043546e46dc7 ("fs/ext4: Only change S_DAX on inode load") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers Tested-by: Disha Goel Reviewed-by: Ojaswin Mujoo Reviewed-by: Jan Kara Link: https://patch.msgid.link/20260730175212.36923-1-ebiggers@kernel.org Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- fs/ext4/crypto.c | 40 ++++++++++++++++++++-------------------- fs/ext4/ialloc.c | 4 ++++ 2 files changed, 24 insertions(+), 20 deletions(-) --- a/fs/ext4/crypto.c +++ b/fs/ext4/crypto.c @@ -144,7 +144,13 @@ static int ext4_set_context(struct inode if (inode->i_ino == EXT4_ROOT_INO) return -EPERM; - if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode))) + /* + * For new encrypted inodes, S_DAX is never set in the first place. + * + * For existing inodes, this is called only on empty directories. ext4 + * never sets S_DAX on directories. + */ + if (WARN_ON_ONCE(IS_DAX(inode))) return -EINVAL; if (ext4_test_inode_flag(inode, EXT4_INODE_DAX)) @@ -164,27 +170,24 @@ static int ext4_set_context(struct inode if (handle) { /* + * __ext4_new_inode() should have already set the encrypt flag + * on the inode and avoided enabling inline data. + */ + if (WARN_ON_ONCE(!IS_ENCRYPTED(inode))) + return -EINVAL; + if (WARN_ON_ONCE(ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA))) + return -EINVAL; + /* * Since the inode is new it is ok to pass the * XATTR_CREATE flag. This is necessary to match the * remaining journal credits check in the set_handle * function with the credits allocated for the new * inode. */ - res = ext4_xattr_set_handle(handle, inode, - EXT4_XATTR_INDEX_ENCRYPTION, - EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, - ctx, len, XATTR_CREATE); - if (!res) { - ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT); - ext4_clear_inode_state(inode, - EXT4_STATE_MAY_INLINE_DATA); - /* - * Update inode->i_flags - S_ENCRYPTED will be enabled, - * S_DAX may be disabled - */ - ext4_set_inode_flags(inode, false); - } - return res; + return ext4_xattr_set_handle(handle, inode, + EXT4_XATTR_INDEX_ENCRYPTION, + EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, + ctx, len, XATTR_CREATE); } res = dquot_initialize(inode); @@ -205,10 +208,7 @@ retry: ctx, len, 0); if (!res) { ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT); - /* - * Update inode->i_flags - S_ENCRYPTED will be enabled, - * S_DAX may be disabled - */ + /* Update inode->i_flags to set S_ENCRYPTED. */ ext4_set_inode_flags(inode, false); res = ext4_mark_inode_dirty(handle, inode); if (res) --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -995,6 +995,8 @@ struct inode *__ext4_new_inode(struct mn err = fscrypt_prepare_new_inode(dir, inode, &encrypt); if (err) goto out; + if (encrypt) + i_flags |= EXT4_ENCRYPT_FL; } err = dquot_initialize(inode); @@ -1304,6 +1306,8 @@ got: ei->i_extra_isize = sbi->s_want_extra_isize; ei->i_inline_off = 0; if (ext4_has_feature_inline_data(sb) && + /* Encrypted inodes cannot have inline data */ + !(ei->i_flags & EXT4_ENCRYPT_FL) && (!(ei->i_flags & (EXT4_DAX_FL|EXT4_EA_INODE_FL)) || S_ISDIR(mode))) ext4_set_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA); ret = inode;