Commit 27977b69 authored Jul 17, 2015 by Theodore Ts'o

ext4 crypto: check for too-short encrypted file names



An encrypted file name should never be shorter than an 16 bytes, the
AES block size.  The 3.10 crypto layer will oops and crash the kernel
if ciphertext shorter than the block size is passed to it.

Fortunately, in modern kernels the crypto layer will not crash the
kernel in this scenario, but nevertheless, it represents a corrupted
directory, and we should detect it and mark the file system as
corrupted so that e2fsck can fix this.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

parent 806c24ad

fs/ext4/crypto_fname.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -329,6 +329,10 @@ int _ext4_fname_disk_to_usr(struct inode *inode,
		return oname->len;
		}
		}
		if (iname->len < EXT4_CRYPTO_BLOCK_SIZE) {
		EXT4_ERROR_INODE(inode, "encrypted inode too small");
		return -EUCLEAN;
		}
		if (EXT4_I(inode)->i_crypt_info)
		return ext4_fname_decrypt(inode, iname, oname);

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