From abdd438b26b409eaccf9c847fcf9c3ab52f1959e Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Sun, 31 May 2015 13:35:39 -0400 Subject: [PATCH] ext4 crypto: handle unexpected lack of encryption keys Fix up attempts by users to try to write to a file when they don't have access to the encryption key. Signed-off-by: Theodore Ts'o --- fs/ext4/crypto.c | 3 ++- fs/ext4/crypto_policy.c | 3 ++- fs/ext4/file.c | 17 ++++++++++------- 3 files changed, 14 insertions(+), 9 deletions(-) diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c index 1c9a8c499369..efcb7c04d172 100644 --- a/fs/ext4/crypto.c +++ b/fs/ext4/crypto.c @@ -104,7 +104,8 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode) unsigned long flags; struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info; - BUG_ON(ci == NULL); + if (ci == NULL) + return ERR_PTR(-ENOKEY); /* * We first try getting the ctx from a free list because in diff --git a/fs/ext4/crypto_policy.c b/fs/ext4/crypto_policy.c index a1d434d0dea8..02c4e5df7afb 100644 --- a/fs/ext4/crypto_policy.c +++ b/fs/ext4/crypto_policy.c @@ -183,7 +183,8 @@ int ext4_inherit_context(struct inode *parent, struct inode *child) if (res < 0) return res; ci = EXT4_I(parent)->i_crypt_info; - BUG_ON(ci == NULL); + if (ci == NULL) + return -ENOKEY; ctx.format = EXT4_ENCRYPTION_CONTEXT_FORMAT_V1; if (DUMMY_ENCRYPTION_ENABLED(EXT4_SB(parent->i_sb))) { diff --git a/fs/ext4/file.c b/fs/ext4/file.c index 875ca6b95a4b..ac517f15741c 100644 --- a/fs/ext4/file.c +++ b/fs/ext4/file.c @@ -226,6 +226,8 @@ static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma) int err = ext4_get_encryption_info(inode); if (err) return 0; + if (ext4_encryption_info(inode) == NULL) + return -ENOKEY; } file_accessed(file); if (IS_DAX(file_inode(file))) { @@ -278,6 +280,13 @@ static int ext4_file_open(struct inode * inode, struct file * filp) ext4_journal_stop(handle); } } + if (ext4_encrypted_inode(inode)) { + ret = ext4_get_encryption_info(inode); + if (ret) + return -EACCES; + if (ext4_encryption_info(inode) == NULL) + return -ENOKEY; + } /* * Set up the jbd2_inode if we are opening the inode for * writing and the journal is present @@ -287,13 +296,7 @@ static int ext4_file_open(struct inode * inode, struct file * filp) if (ret < 0) return ret; } - ret = dquot_file_open(inode, filp); - if (!ret && ext4_encrypted_inode(inode)) { - ret = ext4_get_encryption_info(inode); - if (ret) - ret = -EACCES; - } - return ret; + return dquot_file_open(inode, filp); } /* -- 2.45.2