apparmor: make computing policy hashes conditional on kernel parameter

Allow turning off the computation of the policy hashes via the
apparmor.hash_policy kernel parameter.

Signed-off-by: John Johansen <john.johansen@canonical.com>
This commit is contained in:
John Johansen 2017-01-16 00:43:07 -08:00
parent aa9a39ad8f
commit 31f75bfecd
2 changed files with 33 additions and 30 deletions

View File

@ -165,6 +165,26 @@ static int common_perm(const char *op, const struct path *path, u32 mask,
return error;
}
/**
* common_perm_cond - common permission wrapper around inode cond
* @op: operation being checked
* @path: location to check (NOT NULL)
* @mask: requested permissions mask
*
* Returns: %0 else error code if error or permission denied
*/
static int common_perm_cond(const char *op, const struct path *path, u32 mask)
{
struct path_cond cond = { d_backing_inode(path->dentry)->i_uid,
d_backing_inode(path->dentry)->i_mode
};
if (!path_mediated_fs(path->dentry))
return 0;
return common_perm(op, path, mask, &cond);
}
/**
* common_perm_dir_dentry - common permission wrapper when path is dir, dentry
* @op: operation being checked
@ -184,26 +204,6 @@ static int common_perm_dir_dentry(const char *op, const struct path *dir,
return common_perm(op, &path, mask, cond);
}
/**
* common_perm_path - common permission wrapper when mnt, dentry
* @op: operation being checked
* @path: location to check (NOT NULL)
* @mask: requested permissions mask
*
* Returns: %0 else error code if error or permission denied
*/
static inline int common_perm_path(const char *op, const struct path *path,
u32 mask)
{
struct path_cond cond = { d_backing_inode(path->dentry)->i_uid,
d_backing_inode(path->dentry)->i_mode
};
if (!path_mediated_fs(path->dentry))
return 0;
return common_perm(op, path, mask, &cond);
}
/**
* common_perm_rm - common permission wrapper for operations doing rm
* @op: operation being checked
@ -274,7 +274,7 @@ static int apparmor_path_mknod(const struct path *dir, struct dentry *dentry,
static int apparmor_path_truncate(const struct path *path)
{
return common_perm_path(OP_TRUNC, path, MAY_WRITE | AA_MAY_META_WRITE);
return common_perm_cond(OP_TRUNC, path, MAY_WRITE | AA_MAY_META_WRITE);
}
static int apparmor_path_symlink(const struct path *dir, struct dentry *dentry,
@ -333,17 +333,17 @@ static int apparmor_path_rename(const struct path *old_dir, struct dentry *old_d
static int apparmor_path_chmod(const struct path *path, umode_t mode)
{
return common_perm_path(OP_CHMOD, path, AA_MAY_CHMOD);
return common_perm_cond(OP_CHMOD, path, AA_MAY_CHMOD);
}
static int apparmor_path_chown(const struct path *path, kuid_t uid, kgid_t gid)
{
return common_perm_path(OP_CHOWN, path, AA_MAY_CHOWN);
return common_perm_cond(OP_CHOWN, path, AA_MAY_CHOWN);
}
static int apparmor_inode_getattr(const struct path *path)
{
return common_perm_path(OP_GETATTR, path, AA_MAY_META_READ);
return common_perm_cond(OP_GETATTR, path, AA_MAY_META_READ);
}
static int apparmor_file_open(struct file *file, const struct cred *cred)

View File

@ -825,7 +825,8 @@ int aa_unpack(struct aa_loaddata *udata, struct list_head *lh,
if (error)
goto fail_profile;
error = aa_calc_profile_hash(profile, e.version, start,
if (aa_g_hash_policy)
error = aa_calc_profile_hash(profile, e.version, start,
e.pos - start);
if (error)
goto fail_profile;
@ -841,11 +842,13 @@ int aa_unpack(struct aa_loaddata *udata, struct list_head *lh,
list_add_tail(&ent->list, lh);
}
udata->abi = e.version & K_ABI_MASK;
udata->hash = aa_calc_hash(udata->data, udata->size);
if (IS_ERR(udata->hash)) {
error = PTR_ERR(udata->hash);
udata->hash = NULL;
goto fail;
if (aa_g_hash_policy) {
udata->hash = aa_calc_hash(udata->data, udata->size);
if (IS_ERR(udata->hash)) {
error = PTR_ERR(udata->hash);
udata->hash = NULL;
goto fail;
}
}
return 0;