diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c index 1a0835073663..1acac7fd21b2 100644 --- a/fs/ext4/crypto.c +++ b/fs/ext4/crypto.c @@ -469,3 +469,59 @@ uint32_t ext4_validate_encryption_key_size(uint32_t mode, uint32_t size) return size; return 0; } + +/* + * Validate dentries for encrypted directories to make sure we aren't + * potentially caching stale data after a key has been added or + * removed. + */ +static int ext4_d_revalidate(struct dentry *dentry, unsigned int flags) +{ + struct inode *dir = d_inode(dentry->d_parent); + struct ext4_crypt_info *ci = EXT4_I(dir)->i_crypt_info; + int dir_has_key, cached_with_key; + + if (!ext4_encrypted_inode(dir)) + return 0; + + if (ci && ci->ci_keyring_key && + (ci->ci_keyring_key->flags & ((1 << KEY_FLAG_INVALIDATED) | + (1 << KEY_FLAG_REVOKED) | + (1 << KEY_FLAG_DEAD)))) + ci = NULL; + + /* this should eventually be an flag in d_flags */ + cached_with_key = dentry->d_fsdata != NULL; + dir_has_key = (ci != NULL); + + /* + * If the dentry was cached without the key, and it is a + * negative dentry, it might be a valid name. We can't check + * if the key has since been made available due to locking + * reasons, so we fail the validation so ext4_lookup() can do + * this check. + * + * We also fail the validation if the dentry was created with + * the key present, but we no longer have the key, or vice versa. + */ + if ((!cached_with_key && d_is_negative(dentry)) || + (!cached_with_key && dir_has_key) || + (cached_with_key && !dir_has_key)) { +#if 0 /* Revalidation debug */ + char buf[80]; + char *cp = simple_dname(dentry, buf, sizeof(buf)); + + if (IS_ERR(cp)) + cp = (char *) "???"; + pr_err("revalidate: %s %p %d %d %d\n", cp, dentry->d_fsdata, + cached_with_key, d_is_negative(dentry), + dir_has_key); +#endif + return 0; + } + return 1; +} + +const struct dentry_operations ext4_encrypted_d_ops = { + .d_revalidate = ext4_d_revalidate, +}; diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c index 1d1bca74f844..33f5e2a50cf8 100644 --- a/fs/ext4/dir.c +++ b/fs/ext4/dir.c @@ -111,6 +111,12 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx) int dir_has_error = 0; struct ext4_str fname_crypto_str = {.name = NULL, .len = 0}; + if (ext4_encrypted_inode(inode)) { + err = ext4_get_encryption_info(inode); + if (err && err != -ENOKEY) + return err; + } + if (is_dx_dir(inode)) { err = ext4_dx_readdir(file, ctx); if (err != ERR_BAD_DX_DIR) { @@ -157,8 +163,11 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx) index, 1); file->f_ra.prev_pos = (loff_t)index << PAGE_CACHE_SHIFT; bh = ext4_bread(NULL, inode, map.m_lblk, 0); - if (IS_ERR(bh)) - return PTR_ERR(bh); + if (IS_ERR(bh)) { + err = PTR_ERR(bh); + bh = NULL; + goto errout; + } } if (!bh) { diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 614b79c4576e..c1b4f6ab2148 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -2258,6 +2258,7 @@ struct page *ext4_encrypt(struct inode *inode, struct page *plaintext_page); int ext4_decrypt(struct page *page); int ext4_encrypted_zeroout(struct inode *inode, struct ext4_extent *ex); +extern const struct dentry_operations ext4_encrypted_d_ops; #ifdef CONFIG_EXT4_FS_ENCRYPTION int ext4_init_crypto(void); diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 06c3afcbfac8..c9aad3b8951f 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -1558,6 +1558,24 @@ static struct dentry *ext4_lookup(struct inode *dir, struct dentry *dentry, unsi struct ext4_dir_entry_2 *de; struct buffer_head *bh; + if (ext4_encrypted_inode(dir)) { + int res = ext4_get_encryption_info(dir); + + /* + * This should be a properly defined flag for + * dentry->d_flags when we uplift this to the VFS. + * d_fsdata is set to (void *) 1 if if the dentry is + * created while the directory was encrypted and we + * don't have access to the key. + */ + dentry->d_fsdata = NULL; + if (ext4_encryption_info(dir)) + dentry->d_fsdata = (void *) 1; + d_set_d_op(dentry, &ext4_encrypted_d_ops); + if (res && res != -ENOKEY) + return ERR_PTR(res); + } + if (dentry->d_name.len > EXT4_NAME_LEN) return ERR_PTR(-ENAMETOOLONG); diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c index 6b6b3e751f8c..06fd5f7f993d 100644 --- a/fs/ext4/xattr.c +++ b/fs/ext4/xattr.c @@ -232,6 +232,27 @@ ext4_xattr_check_block(struct inode *inode, struct buffer_head *bh) return error; } +static int +__xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header, + void *end, const char *function, unsigned int line) +{ + struct ext4_xattr_entry *entry = IFIRST(header); + int error = -EFSCORRUPTED; + + if (((void *) header >= end) || + (header->h_magic != le32_to_cpu(EXT4_XATTR_MAGIC))) + goto errout; + error = ext4_xattr_check_names(entry, end, entry); +errout: + if (error) + __ext4_error_inode(inode, function, line, 0, + "corrupted in-inode xattr"); + return error; +} + +#define xattr_check_inode(inode, header, end) \ + __xattr_check_inode((inode), (header), (end), __func__, __LINE__) + static inline int ext4_xattr_check_entry(struct ext4_xattr_entry *entry, size_t size) { @@ -343,7 +364,7 @@ ext4_xattr_ibody_get(struct inode *inode, int name_index, const char *name, header = IHDR(inode, raw_inode); entry = IFIRST(header); end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; - error = ext4_xattr_check_names(entry, end, entry); + error = xattr_check_inode(inode, header, end); if (error) goto cleanup; error = ext4_xattr_find_entry(&entry, name_index, name, @@ -474,7 +495,7 @@ ext4_xattr_ibody_list(struct dentry *dentry, char *buffer, size_t buffer_size) raw_inode = ext4_raw_inode(&iloc); header = IHDR(inode, raw_inode); end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; - error = ext4_xattr_check_names(IFIRST(header), end, IFIRST(header)); + error = xattr_check_inode(inode, header, end); if (error) goto cleanup; error = ext4_xattr_list_entries(dentry, IFIRST(header), @@ -990,8 +1011,7 @@ int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i, is->s.here = is->s.first; is->s.end = (void *)raw_inode + EXT4_SB(inode->i_sb)->s_inode_size; if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) { - error = ext4_xattr_check_names(IFIRST(header), is->s.end, - IFIRST(header)); + error = xattr_check_inode(inode, header, is->s.end); if (error) return error; /* Find the named attribute. */ @@ -1288,6 +1308,10 @@ retry: last = entry; total_ino = sizeof(struct ext4_xattr_ibody_header); + error = xattr_check_inode(inode, header, end); + if (error) + goto cleanup; + free = ext4_xattr_free_space(last, &min_offs, base, &total_ino); if (free >= new_extra_isize) { entry = IFIRST(header);