Commit 63f668f0 authored by Eric Biggers's avatar Eric Biggers
Browse files

fscrypt: improve warning messages for unsupported encryption contexts 



When fs/crypto/ encounters an inode with an invalid encryption context,
currently it prints a warning if the pair of encryption modes are
unrecognized, but it's silent if there are other problems such as
unsupported context size, format, or flags.  To help people debug such
situations, add more warning messages.

Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
parent 886da8b3

fs/crypto/keyinfo.c

+15 −3
Original line number Diff line number Diff line
@@ -510,8 +510,12 @@ int fscrypt_get_encryption_info(struct inode *inode) 
	res = inode->i_sb->s_cop->get_context(inode, &ctx, sizeof(ctx));

	if (res < 0) {

		if (!fscrypt_dummy_context_enabled(inode) ||

		    IS_ENCRYPTED(inode))

		    IS_ENCRYPTED(inode)) {

			fscrypt_warn(inode,

				     "Error %d getting encryption context",

				     res);

			return res;

		}

		/* Fake up a context for an unencrypted directory */

		memset(&ctx, 0, sizeof(ctx));

		ctx.format = FS_ENCRYPTION_CONTEXT_FORMAT_V1;
@@ -519,14 +523,22 @@ int fscrypt_get_encryption_info(struct inode *inode) 
		ctx.filenames_encryption_mode = FS_ENCRYPTION_MODE_AES_256_CTS;

		memset(ctx.master_key_descriptor, 0x42, FS_KEY_DESCRIPTOR_SIZE);

	} else if (res != sizeof(ctx)) {

		fscrypt_warn(inode,

			     "Unknown encryption context size (%d bytes)", res);

		return -EINVAL;

	}



	if (ctx.format != FS_ENCRYPTION_CONTEXT_FORMAT_V1)

	if (ctx.format != FS_ENCRYPTION_CONTEXT_FORMAT_V1) {

		fscrypt_warn(inode, "Unknown encryption context version (%d)",

			     ctx.format);

		return -EINVAL;

	}



	if (ctx.flags & ~FS_POLICY_FLAGS_VALID)

	if (ctx.flags & ~FS_POLICY_FLAGS_VALID) {

		fscrypt_warn(inode, "Unknown encryption context flags (0x%02x)",

			     ctx.flags);

		return -EINVAL;

	}



	crypt_info = kmem_cache_zalloc(fscrypt_info_cachep, GFP_NOFS);

	if (!crypt_info)

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