From 3b06b3ebf44170c90c893c6c80916db6e922b9f2 Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Tue, 24 May 2011 03:49:02 -0500 Subject: eCryptfs: Fix new inode race condition Only unlock and d_add() new inodes after the plaintext inode size has been read from the lower filesystem. This fixes a race condition that was sometimes seen during a multi-job kernel build in an eCryptfs mount. https://bugzilla.kernel.org/show_bug.cgi?id=36002 Signed-off-by: Tyler Hicks Reported-by: David Tested-by: David --- fs/ecryptfs/inode.c | 42 ++++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 20 deletions(-) (limited to 'fs/ecryptfs/inode.c') diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index fc7d2b748503..f0ad965d7d51 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -259,7 +259,8 @@ static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry) "context; rc = [%d]\n", rc); goto out; } - rc = ecryptfs_get_lower_file(ecryptfs_dentry); + rc = ecryptfs_get_lower_file(ecryptfs_dentry, + ecryptfs_dentry->d_inode); if (rc) { printk(KERN_ERR "%s: Error attempting to initialize " "the lower file for the dentry with name " @@ -350,50 +351,51 @@ static int ecryptfs_lookup_interpose(struct dentry *ecryptfs_dentry, __func__, rc); goto out; } - if (inode->i_state & I_NEW) - unlock_new_inode(inode); - d_add(ecryptfs_dentry, inode); - if (S_ISDIR(lower_inode->i_mode)) - goto out; - if (S_ISLNK(lower_inode->i_mode)) - goto out; - if (special_file(lower_inode->i_mode)) + if (!S_ISREG(inode->i_mode)) { + if (inode->i_state & I_NEW) + unlock_new_inode(inode); + d_add(ecryptfs_dentry, inode); goto out; + } /* Released in this function */ page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2, GFP_USER); if (!page_virt) { printk(KERN_ERR "%s: Cannot kmem_cache_zalloc() a page\n", __func__); rc = -ENOMEM; + make_bad_inode(inode); goto out; } - rc = ecryptfs_get_lower_file(ecryptfs_dentry); + rc = ecryptfs_get_lower_file(ecryptfs_dentry, inode); if (rc) { printk(KERN_ERR "%s: Error attempting to initialize " "the lower file for the dentry with name " "[%s]; rc = [%d]\n", __func__, ecryptfs_dentry->d_name.name, rc); + make_bad_inode(inode); goto out_free_kmem; } put_lower = 1; - crypt_stat = &ecryptfs_inode_to_private( - ecryptfs_dentry->d_inode)->crypt_stat; + crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat; /* TODO: lock for crypt_stat comparison */ if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)) ecryptfs_set_default_sizes(crypt_stat); - rc = ecryptfs_read_and_validate_header_region(page_virt, - ecryptfs_dentry->d_inode); + rc = ecryptfs_read_and_validate_header_region(page_virt, inode); if (rc) { memset(page_virt, 0, PAGE_CACHE_SIZE); rc = ecryptfs_read_and_validate_xattr_region(page_virt, - ecryptfs_dentry); + inode); if (rc) { rc = 0; - goto out_free_kmem; + goto unlock_inode; } crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; } - ecryptfs_i_size_init(page_virt, ecryptfs_dentry->d_inode); + ecryptfs_i_size_init(page_virt, inode); +unlock_inode: + if (inode->i_state & I_NEW) + unlock_new_inode(inode); + d_add(ecryptfs_dentry, inode); out_free_kmem: kmem_cache_free(ecryptfs_header_cache_2, page_virt); goto out; @@ -403,7 +405,7 @@ out_put: d_drop(ecryptfs_dentry); out: if (put_lower) - ecryptfs_put_lower_file(ecryptfs_dentry->d_inode); + ecryptfs_put_lower_file(inode); return rc; } @@ -843,7 +845,7 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia, lower_ia->ia_valid &= ~ATTR_SIZE; return 0; } - rc = ecryptfs_get_lower_file(dentry); + rc = ecryptfs_get_lower_file(dentry, inode); if (rc) return rc; crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat; @@ -999,7 +1001,7 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia) mount_crypt_stat = &ecryptfs_superblock_to_private( dentry->d_sb)->mount_crypt_stat; - rc = ecryptfs_get_lower_file(dentry); + rc = ecryptfs_get_lower_file(dentry, inode); if (rc) { mutex_unlock(&crypt_stat->cs_mutex); goto out; -- cgit v1.2.3