From 5858bdad4d0d0fc18bf29f34c3ac836e0b59441f Mon Sep 17 00:00:00 2001
From: Hongjie Fang <hongjiefang@asrmicro.com>
Date: Wed, 22 May 2019 10:02:53 +0800
Subject: [PATCH] fscrypt: don't set policy for a dead directory
Git-commit: 5858bdad4d0d0fc18bf29f34c3ac836e0b59441f
Patch-mainline: v5.3-rc1
References: bsc#1163846

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: 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>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Jan Kara <jack@suse.cz>

---
 fs/crypto/policy.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c
index d536889ac31b..4941fe8471ce 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
-- 
2.16.4