fscrypt: don't set policy for a dead directory

BugLink: https://bugs.launchpad.net/bugs/1838467

commit 5858bdad upstream.

The directory may have been removed when entering
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: 9bd8212f ("ext4 crypto: add encryption policy and password salt support")
Cc: <stable@vger.kernel.org> # v4.1+
Signed-off-by: Hongjie Fang <hongjiefang@asrmicro.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

fs/ext4/crypto_policy.c

@@ -111,6 +111,8 @@ int ext4_process_policy(const struct ext4_encryption_policy *policy,
 	if (!ext4_inode_has_encryption_context(inode)) {
 		if (!S_ISDIR(inode->i_mode))
 			return -EINVAL;
+		if (IS_DEADDIR(inode))
+			return -ENOENT;
 		if (!ext4_empty_dir(inode))
 			return -ENOTEMPTY;
 		return ext4_create_encryption_context_from_policy(inode,

fs/f2fs/crypto_policy.c

@@ -99,6 +99,8 @@ int f2fs_process_policy(const struct f2fs_encryption_policy *policy,
 		return -EINVAL;
 
 	if (!f2fs_inode_has_encryption_context(inode)) {
+		if (IS_DEADDIR(inode))
+			return -ENOENT;
 		if (!f2fs_empty_dir(inode))
 			return -ENOTEMPTY;
 		return f2fs_create_encryption_context_from_policy(inode,