[PATCH v5 22/38] SELinux: Abstract use of cred security blob
From: Casey Schaufler
Date: Mon Nov 26 2018 - 18:43:39 EST
Don't use the cred->security pointer directly.
Provide a helper function that provides the security blob pointer.
Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
[kees: adjusted for ordered init series]
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
security/selinux/hooks.c | 54 +++++++++++++++++++--------------------
security/selinux/include/objsec.h | 5 ++++
security/selinux/xfrm.c | 4 +--
3 files changed, 34 insertions(+), 29 deletions(-)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index edd5b8dd3e56..24b6b459fa2a 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -225,7 +225,7 @@ static inline u32 cred_sid(const struct cred *cred)
{
const struct task_security_struct *tsec;
- tsec = cred->security;
+ tsec = selinux_cred(cred);
return tsec->sid;
}
@@ -461,7 +461,7 @@ static int may_context_mount_sb_relabel(u32 sid,
struct superblock_security_struct *sbsec,
const struct cred *cred)
{
- const struct task_security_struct *tsec = cred->security;
+ const struct task_security_struct *tsec = selinux_cred(cred);
int rc;
rc = avc_has_perm(&selinux_state,
@@ -480,7 +480,7 @@ static int may_context_mount_inode_relabel(u32 sid,
struct superblock_security_struct *sbsec,
const struct cred *cred)
{
- const struct task_security_struct *tsec = cred->security;
+ const struct task_security_struct *tsec = selinux_cred(cred);
int rc;
rc = avc_has_perm(&selinux_state,
tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
@@ -1951,7 +1951,7 @@ static int may_create(struct inode *dir,
struct dentry *dentry,
u16 tclass)
{
- const struct task_security_struct *tsec = current_security();
+ const struct task_security_struct *tsec = selinux_cred(current_cred());
struct inode_security_struct *dsec;
struct superblock_security_struct *sbsec;
u32 sid, newsid;
@@ -1973,7 +1973,7 @@ static int may_create(struct inode *dir,
if (rc)
return rc;
- rc = selinux_determine_inode_label(current_security(), dir,
+ rc = selinux_determine_inode_label(selinux_cred(current_cred()), dir,
&dentry->d_name, tclass, &newsid);
if (rc)
return rc;
@@ -2480,8 +2480,8 @@ static int selinux_bprm_set_creds(struct linux_binprm *bprm)
if (bprm->called_set_creds)
return 0;
- old_tsec = current_security();
- new_tsec = bprm->cred->security;
+ old_tsec = selinux_cred(current_cred());
+ new_tsec = selinux_cred(bprm->cred);
isec = inode_security(inode);
/* Default to the current task SID. */
@@ -2645,7 +2645,7 @@ static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
struct rlimit *rlim, *initrlim;
int rc, i;
- new_tsec = bprm->cred->security;
+ new_tsec = selinux_cred(bprm->cred);
if (new_tsec->sid == new_tsec->osid)
return;
@@ -2688,7 +2688,7 @@ static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
*/
static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
{
- const struct task_security_struct *tsec = current_security();
+ const struct task_security_struct *tsec = selinux_cred(current_cred());
struct itimerval itimer;
u32 osid, sid;
int rc, i;
@@ -2991,7 +2991,7 @@ static int selinux_dentry_init_security(struct dentry *dentry, int mode,
u32 newsid;
int rc;
- rc = selinux_determine_inode_label(current_security(),
+ rc = selinux_determine_inode_label(selinux_cred(current_cred()),
d_inode(dentry->d_parent), name,
inode_mode_to_security_class(mode),
&newsid);
@@ -3011,14 +3011,14 @@ static int selinux_dentry_create_files_as(struct dentry *dentry, int mode,
int rc;
struct task_security_struct *tsec;
- rc = selinux_determine_inode_label(old->security,
+ rc = selinux_determine_inode_label(selinux_cred(old),
d_inode(dentry->d_parent), name,
inode_mode_to_security_class(mode),
&newsid);
if (rc)
return rc;
- tsec = new->security;
+ tsec = selinux_cred(new);
tsec->create_sid = newsid;
return 0;
}
@@ -3028,7 +3028,7 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
const char **name,
void **value, size_t *len)
{
- const struct task_security_struct *tsec = current_security();
+ const struct task_security_struct *tsec = selinux_cred(current_cred());
struct superblock_security_struct *sbsec;
u32 newsid, clen;
int rc;
@@ -3038,7 +3038,7 @@ static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
newsid = tsec->create_sid;
- rc = selinux_determine_inode_label(current_security(),
+ rc = selinux_determine_inode_label(selinux_cred(current_cred()),
dir, qstr,
inode_mode_to_security_class(inode->i_mode),
&newsid);
@@ -3500,7 +3500,7 @@ static int selinux_inode_copy_up(struct dentry *src, struct cred **new)
return -ENOMEM;
}
- tsec = new_creds->security;
+ tsec = selinux_cred(new_creds);
/* Get label from overlay inode and set it in create_sid */
selinux_inode_getsecid(d_inode(src), &sid);
tsec->create_sid = sid;
@@ -3920,7 +3920,7 @@ static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp)
*/
static void selinux_cred_free(struct cred *cred)
{
- struct task_security_struct *tsec = cred->security;
+ struct task_security_struct *tsec = selinux_cred(cred);
/*
* cred->security == NULL if security_cred_alloc_blank() or
@@ -3940,7 +3940,7 @@ static int selinux_cred_prepare(struct cred *new, const struct cred *old,
const struct task_security_struct *old_tsec;
struct task_security_struct *tsec;
- old_tsec = old->security;
+ old_tsec = selinux_cred(old);
tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
if (!tsec)
@@ -3955,8 +3955,8 @@ static int selinux_cred_prepare(struct cred *new, const struct cred *old,
*/
static void selinux_cred_transfer(struct cred *new, const struct cred *old)
{
- const struct task_security_struct *old_tsec = old->security;
- struct task_security_struct *tsec = new->security;
+ const struct task_security_struct *old_tsec = selinux_cred(old);
+ struct task_security_struct *tsec = selinux_cred(new);
*tsec = *old_tsec;
}
@@ -3972,7 +3972,7 @@ static void selinux_cred_getsecid(const struct cred *c, u32 *secid)
*/
static int selinux_kernel_act_as(struct cred *new, u32 secid)
{
- struct task_security_struct *tsec = new->security;
+ struct task_security_struct *tsec = selinux_cred(new);
u32 sid = current_sid();
int ret;
@@ -3997,7 +3997,7 @@ static int selinux_kernel_act_as(struct cred *new, u32 secid)
static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
{
struct inode_security_struct *isec = inode_security(inode);
- struct task_security_struct *tsec = new->security;
+ struct task_security_struct *tsec = selinux_cred(new);
u32 sid = current_sid();
int ret;
@@ -4546,7 +4546,7 @@ static int sock_has_perm(struct sock *sk, u32 perms)
static int selinux_socket_create(int family, int type,
int protocol, int kern)
{
- const struct task_security_struct *tsec = current_security();
+ const struct task_security_struct *tsec = selinux_cred(current_cred());
u32 newsid;
u16 secclass;
int rc;
@@ -4566,7 +4566,7 @@ static int selinux_socket_create(int family, int type,
static int selinux_socket_post_create(struct socket *sock, int family,
int type, int protocol, int kern)
{
- const struct task_security_struct *tsec = current_security();
+ const struct task_security_struct *tsec = selinux_cred(current_cred());
struct inode_security_struct *isec = inode_security_novalidate(SOCK_INODE(sock));
struct sk_security_struct *sksec;
u16 sclass = socket_type_to_security_class(family, type, protocol);
@@ -5444,7 +5444,7 @@ static int selinux_secmark_relabel_packet(u32 sid)
const struct task_security_struct *__tsec;
u32 tsid;
- __tsec = current_security();
+ __tsec = selinux_cred(current_cred());
tsid = __tsec->sid;
return avc_has_perm(&selinux_state,
@@ -6381,7 +6381,7 @@ static int selinux_getprocattr(struct task_struct *p,
unsigned len;
rcu_read_lock();
- __tsec = __task_cred(p)->security;
+ __tsec = selinux_cred(__task_cred(p));
if (current != p) {
error = avc_has_perm(&selinux_state,
@@ -6504,7 +6504,7 @@ static int selinux_setprocattr(const char *name, void *value, size_t size)
operation. See selinux_bprm_set_creds for the execve
checks and may_create for the file creation checks. The
operation will then fail if the context is not permitted. */
- tsec = new->security;
+ tsec = selinux_cred(new);
if (!strcmp(name, "exec")) {
tsec->exec_sid = sid;
} else if (!strcmp(name, "fscreate")) {
@@ -6633,7 +6633,7 @@ static int selinux_key_alloc(struct key *k, const struct cred *cred,
if (!ksec)
return -ENOMEM;
- tsec = cred->security;
+ tsec = selinux_cred(cred);
if (tsec->keycreate_sid)
ksec->sid = tsec->keycreate_sid;
else
diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
index cc5e26b0161b..734b6833bdff 100644
--- a/security/selinux/include/objsec.h
+++ b/security/selinux/include/objsec.h
@@ -158,4 +158,9 @@ struct bpf_security_struct {
u32 sid; /*SID of bpf obj creater*/
};
+static inline struct task_security_struct *selinux_cred(const struct cred *cred)
+{
+ return cred->security;
+}
+
#endif /* _SELINUX_OBJSEC_H_ */
diff --git a/security/selinux/xfrm.c b/security/selinux/xfrm.c
index 91dc3783ed94..8ffe7e1053c4 100644
--- a/security/selinux/xfrm.c
+++ b/security/selinux/xfrm.c
@@ -79,7 +79,7 @@ static int selinux_xfrm_alloc_user(struct xfrm_sec_ctx **ctxp,
gfp_t gfp)
{
int rc;
- const struct task_security_struct *tsec = current_security();
+ const struct task_security_struct *tsec = selinux_cred(current_cred());
struct xfrm_sec_ctx *ctx = NULL;
u32 str_len;
@@ -138,7 +138,7 @@ static void selinux_xfrm_free(struct xfrm_sec_ctx *ctx)
*/
static int selinux_xfrm_delete(struct xfrm_sec_ctx *ctx)
{
- const struct task_security_struct *tsec = current_security();
+ const struct task_security_struct *tsec = selinux_cred(current_cred());
if (!ctx)
return 0;
--
2.14.5