From 069ddcda37b2cf5bb4b6031a944c0e9359213262 Mon Sep 17 00:00:00 2001 From: Tyler Hicks Date: Mon, 11 Jun 2012 15:42:32 -0700 Subject: eCryptfs: Copy up POSIX ACL and read-only flags from lower mount When the eCryptfs mount options do not include '-o acl', but the lower filesystem's mount options do include 'acl', the MS_POSIXACL flag is not flipped on in the eCryptfs super block flags. This flag is what the VFS checks in do_last() when deciding if the current umask should be applied to a newly created inode's mode or not. When a default POSIX ACL mask is set on a directory, the current umask is incorrectly applied to new inodes created in the directory. This patch ignores the MS_POSIXACL flag passed into ecryptfs_mount() and sets the flag on the eCryptfs super block depending on the flag's presence on the lower super block. Additionally, it is incorrect to allow a writeable eCryptfs mount on top of a read-only lower mount. This missing check did not allow writes to the read-only lower mount because permissions checks are still performed on the lower filesystem's objects but it is best to simply not allow a rw mount on top of ro mount. However, a ro eCryptfs mount on top of a rw mount is valid and still allowed. https://launchpad.net/bugs/1009207 Signed-off-by: Tyler Hicks Reported-by: Stefan Beller Cc: John Johansen --- fs/ecryptfs/main.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'fs/ecryptfs/main.c') diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c index 68954937a071..df217dc9f1d9 100644 --- a/fs/ecryptfs/main.c +++ b/fs/ecryptfs/main.c @@ -505,7 +505,6 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags goto out; } - s->s_flags = flags; rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY); if (rc) goto out1; @@ -541,6 +540,15 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags } ecryptfs_set_superblock_lower(s, path.dentry->d_sb); + + /** + * Set the POSIX ACL flag based on whether they're enabled in the lower + * mount. Force a read-only eCryptfs mount if the lower mount is ro. + * Allow a ro eCryptfs mount even when the lower mount is rw. + */ + s->s_flags = flags & ~MS_POSIXACL; + s->s_flags |= path.dentry->d_sb->s_flags & (MS_RDONLY | MS_POSIXACL); + s->s_maxbytes = path.dentry->d_sb->s_maxbytes; s->s_blocksize = path.dentry->d_sb->s_blocksize; s->s_magic = ECRYPTFS_SUPER_MAGIC; -- cgit v1.2.1 From 5f5b331d5c21228a6519dcb793fc1629646c51a6 Mon Sep 17 00:00:00 2001 From: Tim Sally Date: Thu, 12 Jul 2012 19:10:24 -0400 Subject: eCryptfs: check for eCryptfs cipher support at mount The issue occurs when eCryptfs is mounted with a cipher supported by the crypto subsystem but not by eCryptfs. The mount succeeds and an error does not occur until a write. This change checks for eCryptfs cipher support at mount time. Resolves Launchpad issue #338914, reported by Tyler Hicks in 03/2009. https://bugs.launchpad.net/ecryptfs/+bug/338914 Signed-off-by: Tim Sally Signed-off-by: Tyler Hicks --- fs/ecryptfs/main.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'fs/ecryptfs/main.c') diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c index df217dc9f1d9..923f6aa09cb3 100644 --- a/fs/ecryptfs/main.c +++ b/fs/ecryptfs/main.c @@ -279,6 +279,7 @@ static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options, char *fnek_src; char *cipher_key_bytes_src; char *fn_cipher_key_bytes_src; + u8 cipher_code; *check_ruid = 0; @@ -420,6 +421,18 @@ static int ecryptfs_parse_options(struct ecryptfs_sb_info *sbi, char *options, && !fn_cipher_key_bytes_set) mount_crypt_stat->global_default_fn_cipher_key_bytes = mount_crypt_stat->global_default_cipher_key_size; + + cipher_code = ecryptfs_code_for_cipher_string( + mount_crypt_stat->global_default_cipher_name, + mount_crypt_stat->global_default_cipher_key_size); + if (!cipher_code) { + ecryptfs_printk(KERN_ERR, + "eCryptfs doesn't support cipher: %s", + mount_crypt_stat->global_default_cipher_name); + rc = -EINVAL; + goto out; + } + mutex_lock(&key_tfm_list_mutex); if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, NULL)) { -- cgit v1.2.1