On Fri, May 29, 2015 at 04:44:29PM -0400, Theodore Ts'o wrote:
> I don't think that's the right way to go. We should add checks to
> ext4_file_open, sure. But the problem is that i_crypt_info can get
> set to NULL after the file is succesfully opened. So we need to
> handle i_crypt_info being NULL everywhere. So the BUG_ON() in
> ext4_get_crypto_ctx() needs to be replaced with:
>
> if (ci == NULL)
> return ERR_PTR(-ENOKEY);
This is what I had in mind....
- Ted
commit 3cde0c5d3125697c4b02c32054a378dc71ebfdb5
Author: Theodore Ts'o <tytso@xxxxxxx>
Date: Sun May 31 08:12:34 2015 -0400
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 <tytso@xxxxxxx>
diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c
index ac2419c..6634478 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 a1d434d..02c4e5d 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 875ca6b..ac517f1 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);
}
/*
--
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