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				https://kernel.googlesource.com/pub/scm/linux/kernel/git/torvalds/linux
				synced 2025-11-04 16:52:06 +10:00 
			
		
		
		
	Now ->max_namelen() is only called to limit the filename length when adding NUL padding, and only for real filenames -- not symlink targets. It also didn't give the correct length for symlink targets anyway since it forgot to subtract 'sizeof(struct fscrypt_symlink_data)'. Thus, change ->max_namelen from a function to a simple 'unsigned int' that gives the filesystem's maximum filename length. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
		
			
				
	
	
		
			86 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			86 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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#include "ubifs.h"
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static int ubifs_crypt_get_context(struct inode *inode, void *ctx, size_t len)
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{
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	return ubifs_xattr_get(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT,
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			       ctx, len);
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}
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static int ubifs_crypt_set_context(struct inode *inode, const void *ctx,
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				   size_t len, void *fs_data)
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{
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	/*
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	 * Creating an encryption context is done unlocked since we
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	 * operate on a new inode which is not visible to other users
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	 * at this point. So, no need to check whether inode is locked.
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	 */
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	return ubifs_xattr_set(inode, UBIFS_XATTR_NAME_ENCRYPTION_CONTEXT,
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			       ctx, len, 0, false);
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}
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static bool ubifs_crypt_empty_dir(struct inode *inode)
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{
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	return ubifs_check_dir_empty(inode) == 0;
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}
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int ubifs_encrypt(const struct inode *inode, struct ubifs_data_node *dn,
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		  unsigned int in_len, unsigned int *out_len, int block)
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{
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	struct ubifs_info *c = inode->i_sb->s_fs_info;
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	void *p = &dn->data;
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	struct page *ret;
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	unsigned int pad_len = round_up(in_len, UBIFS_CIPHER_BLOCK_SIZE);
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	ubifs_assert(pad_len <= *out_len);
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	dn->compr_size = cpu_to_le16(in_len);
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	/* pad to full block cipher length */
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	if (pad_len != in_len)
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		memset(p + in_len, 0, pad_len - in_len);
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	ret = fscrypt_encrypt_page(inode, virt_to_page(&dn->data), pad_len,
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			offset_in_page(&dn->data), block, GFP_NOFS);
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	if (IS_ERR(ret)) {
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		ubifs_err(c, "fscrypt_encrypt_page failed: %ld", PTR_ERR(ret));
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		return PTR_ERR(ret);
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	}
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	*out_len = pad_len;
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	return 0;
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}
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int ubifs_decrypt(const struct inode *inode, struct ubifs_data_node *dn,
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		  unsigned int *out_len, int block)
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{
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	struct ubifs_info *c = inode->i_sb->s_fs_info;
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	int err;
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	unsigned int clen = le16_to_cpu(dn->compr_size);
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	unsigned int dlen = *out_len;
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	if (clen <= 0 || clen > UBIFS_BLOCK_SIZE || clen > dlen) {
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		ubifs_err(c, "bad compr_size: %i", clen);
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		return -EINVAL;
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	}
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	ubifs_assert(dlen <= UBIFS_BLOCK_SIZE);
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	err = fscrypt_decrypt_page(inode, virt_to_page(&dn->data), dlen,
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			offset_in_page(&dn->data), block);
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	if (err) {
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		ubifs_err(c, "fscrypt_decrypt_page failed: %i", err);
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		return err;
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	}
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	*out_len = clen;
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	return 0;
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}
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const struct fscrypt_operations ubifs_crypt_operations = {
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	.flags			= FS_CFLG_OWN_PAGES,
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	.key_prefix		= "ubifs:",
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	.get_context		= ubifs_crypt_get_context,
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	.set_context		= ubifs_crypt_set_context,
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	.empty_dir		= ubifs_crypt_empty_dir,
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	.max_namelen		= UBIFS_MAX_NLEN,
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};
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