From: Hongjie Fang hongjiefang@asrmicro.com

commit 5858bdad4d0d0fc18bf29f34c3ac836e0b59441f upstream. [Please apply to 4.9-stable.]

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

diff --git a/fs/crypto/policy.c b/fs/crypto/policy.c index c160d2d0e18d77..57a97b38a2fa2c 100644 --- a/fs/crypto/policy.c +++ b/fs/crypto/policy.c @@ -114,6 +114,8 @@ int fscrypt_process_policy(struct file *filp, if (!inode_has_encryption_context(inode)) { if (!S_ISDIR(inode->i_mode)) ret = -ENOTDIR; + else if (IS_DEADDIR(inode)) + ret = -ENOENT; else if (!inode->i_sb->s_cop->empty_dir) ret = -EOPNOTSUPP; else if (!inode->i_sb->s_cop->empty_dir(inode))