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 <tyhicks@linux.vnet.ibm.com>
Reported-by: David <david@unsolicited.net>
Tested-by: David <david@unsolicited.net>
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index fc7d2b7..f0ad965 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -259,7 +259,8 @@
"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 @@
__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))
+ if (!S_ISREG(inode->i_mode)) {
+ if (inode->i_state & I_NEW)
+ unlock_new_inode(inode);
+ d_add(ecryptfs_dentry, inode);
goto out;
- if (S_ISLNK(lower_inode->i_mode))
- goto out;
- if (special_file(lower_inode->i_mode))
- 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 @@
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 @@
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 @@
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;