[V3] fscrypt: don't set policy for a dead directory
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Message ID 1558490573-21562-1-git-send-email-hongjiefang@asrmicro.com
State Accepted
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  • [V3] fscrypt: don't set policy for a dead directory
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Commit Message

Hongjie Fang May 22, 2019, 2:02 a.m. UTC
the directory maybe has been removed when enter fscrypt_ioctl_set_policy().
if so, the empty_dir() check will return error for ext4 file system.

ext4_rmdir() sets i_size = 0, then ext4_empty_dir() reports an error
because 'inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)'.
if the fs is mounted with errors=panic, it will trigger a panic issue.

add the check IS_DEADDIR() to fix this problem.

Fixes: 9bd8212f981e ("ext4 crypto: add encryption policy and password salt support")
Cc: <stable@vger.kernel.org> # v4.1+
Signed-off-by: Hongjie Fang <hongjiefang@asrmicro.com>
---
 fs/crypto/policy.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Eric Biggers May 29, 2019, 8:50 p.m. UTC | #1
On Wed, May 22, 2019 at 10:02:53AM +0800, Hongjie Fang wrote:
> the directory maybe has been removed when enter fscrypt_ioctl_set_policy().
> if so, the empty_dir() check will return error for ext4 file system.
> 
> ext4_rmdir() sets i_size = 0, then ext4_empty_dir() reports an error
> because 'inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)'.
> if the fs is mounted with errors=panic, it will trigger a panic issue.
> 
> add the check IS_DEADDIR() to fix this problem.
> 
> Fixes: 9bd8212f981e ("ext4 crypto: add encryption policy and password salt support")
> Cc: <stable@vger.kernel.org> # v4.1+
> Signed-off-by: Hongjie Fang <hongjiefang@asrmicro.com>
> ---
>  fs/crypto/policy.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c
> index d536889..4941fe8 100644
> --- a/fs/crypto/policy.c
> +++ b/fs/crypto/policy.c
> @@ -81,6 +81,8 @@ int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg)
>  	if (ret == -ENODATA) {
>  		if (!S_ISDIR(inode->i_mode))
>  			ret = -ENOTDIR;
> +		else if (IS_DEADDIR(inode))
> +			ret = -ENOENT;
>  		else if (!inode->i_sb->s_cop->empty_dir(inode))
>  			ret = -ENOTEMPTY;
>  		else
> -- 
> 1.9.1
> 

Applied to fscrypt.git for v5.3.

- Eric

Patch
diff mbox series

diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c
index d536889..4941fe8 100644
--- a/fs/crypto/policy.c
+++ b/fs/crypto/policy.c
@@ -81,6 +81,8 @@  int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg)
 	if (ret == -ENODATA) {
 		if (!S_ISDIR(inode->i_mode))
 			ret = -ENOTDIR;
+		else if (IS_DEADDIR(inode))
+			ret = -ENOENT;
 		else if (!inode->i_sb->s_cop->empty_dir(inode))
 			ret = -ENOTEMPTY;
 		else