The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
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
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
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