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authorTyler Hicks <tyhicks@linux.vnet.ibm.com>2011-03-15 14:54:00 -0500
committerTyler Hicks <tyhicks@linux.vnet.ibm.com>2011-04-25 18:45:06 -0500
commit3aeb86ea4cd15f728147a3bd5469a205ada8c767 (patch)
tree6219c664f7938fa8e5e8a2efa93aab7bcc38c12f
parent332ab16f830f59e7621ae8eb2c353dc135a316f6 (diff)
downloadlinux-3aeb86ea4cd15f728147a3bd5469a205ada8c767.tar.gz
eCryptfs: Handle failed metadata read in lookup
When failing to read the lower file's crypto metadata during a lookup, eCryptfs must continue on without throwing an error. For example, there may be a plaintext file in the lower mount point that the user wants to delete through the eCryptfs mount. If an error is encountered while reading the metadata in lookup(), the eCryptfs inode's size could be incorrect. We must be sure to reread the plaintext inode size from the metadata when performing an open() or setattr(). The metadata is already being read in those paths, so this adds minimal performance overhead. This patch introduces a flag which will track whether or not the plaintext inode size has been read so that an incorrect i_size can be fixed in the open() or setattr() paths. https://bugs.launchpad.net/bugs/509180 Cc: <stable@kernel.org> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>
-rw-r--r--fs/ecryptfs/crypto.c21
-rw-r--r--fs/ecryptfs/ecryptfs_kernel.h2
-rw-r--r--fs/ecryptfs/file.c3
-rw-r--r--fs/ecryptfs/inode.c18
4 files changed, 28 insertions, 16 deletions
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index d2a70a4561f..b8d5c809102 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1452,6 +1452,25 @@ static void set_default_header_data(struct ecryptfs_crypt_stat *crypt_stat)
crypt_stat->metadata_size = ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE;
}
+void ecryptfs_i_size_init(const char *page_virt, struct inode *inode)
+{
+ struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
+ struct ecryptfs_crypt_stat *crypt_stat;
+ u64 file_size;
+
+ crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
+ mount_crypt_stat =
+ &ecryptfs_superblock_to_private(inode->i_sb)->mount_crypt_stat;
+ if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
+ file_size = i_size_read(ecryptfs_inode_to_lower(inode));
+ if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
+ file_size += crypt_stat->metadata_size;
+ } else
+ file_size = get_unaligned_be64(page_virt);
+ i_size_write(inode, (loff_t)file_size);
+ crypt_stat->flags |= ECRYPTFS_I_SIZE_INITIALIZED;
+}
+
/**
* ecryptfs_read_headers_virt
* @page_virt: The virtual address into which to read the headers
@@ -1482,6 +1501,8 @@ static int ecryptfs_read_headers_virt(char *page_virt,
rc = -EINVAL;
goto out;
}
+ if (!(crypt_stat->flags & ECRYPTFS_I_SIZE_INITIALIZED))
+ ecryptfs_i_size_init(page_virt, ecryptfs_dentry->d_inode);
offset += MAGIC_ECRYPTFS_MARKER_SIZE_BYTES;
rc = ecryptfs_process_flags(crypt_stat, (page_virt + offset),
&bytes_read);
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index 380bee1094c..e70282775e2 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -269,6 +269,7 @@ struct ecryptfs_crypt_stat {
#define ECRYPTFS_ENCFN_USE_MOUNT_FNEK 0x00000800
#define ECRYPTFS_ENCFN_USE_FEK 0x00001000
#define ECRYPTFS_UNLINK_SIGS 0x00002000
+#define ECRYPTFS_I_SIZE_INITIALIZED 0x00004000
u32 flags;
unsigned int file_version;
size_t iv_bytes;
@@ -628,6 +629,7 @@ struct ecryptfs_open_req {
int ecryptfs_interpose(struct dentry *hidden_dentry,
struct dentry *this_dentry, struct super_block *sb,
u32 flags);
+void ecryptfs_i_size_init(const char *page_virt, struct inode *inode);
int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
struct dentry *lower_dentry,
struct inode *ecryptfs_dir_inode);
diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c
index 146c4edff70..566e5472f78 100644
--- a/fs/ecryptfs/file.c
+++ b/fs/ecryptfs/file.c
@@ -235,7 +235,8 @@ static int ecryptfs_open(struct inode *inode, struct file *file)
goto out_put;
}
rc = 0;
- crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
+ crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
+ | ECRYPTFS_ENCRYPTED);
mutex_unlock(&crypt_stat->cs_mutex);
goto out;
}
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index f6b388638c3..2c19d362d2d 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -225,10 +225,8 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
struct dentry *lower_dir_dentry;
struct vfsmount *lower_mnt;
struct inode *lower_inode;
- struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
struct ecryptfs_crypt_stat *crypt_stat;
char *page_virt = NULL;
- u64 file_size;
int put_lower = 0, rc = 0;
lower_dir_dentry = lower_dentry->d_parent;
@@ -302,18 +300,7 @@ int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
}
crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
}
- mount_crypt_stat = &ecryptfs_superblock_to_private(
- ecryptfs_dentry->d_sb)->mount_crypt_stat;
- if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
- if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
- file_size = (crypt_stat->metadata_size
- + i_size_read(lower_dentry->d_inode));
- else
- file_size = i_size_read(lower_dentry->d_inode);
- } else {
- file_size = get_unaligned_be64(page_virt);
- }
- i_size_write(ecryptfs_dentry->d_inode, (loff_t)file_size);
+ ecryptfs_i_size_init(page_virt, ecryptfs_dentry->d_inode);
out_free_kmem:
kmem_cache_free(ecryptfs_header_cache_2, page_virt);
goto out;
@@ -937,7 +924,8 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
goto out;
}
rc = 0;
- crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
+ crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
+ | ECRYPTFS_ENCRYPTED);
}
}
mutex_unlock(&crypt_stat->cs_mutex);