CRED: Wrap task credential accesses in the SYSV IPC subsystem
Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.
Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().
Change some task->e?[ug]id to task_e?[ug]id(). In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/ipc/util.c b/ipc/util.c
index 49b3ea6..c8a7670 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -258,6 +258,8 @@
int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
{
+ uid_t euid;
+ gid_t egid;
int id, err;
if (size > IPCMNI)
@@ -272,8 +274,9 @@
ids->in_use++;
- new->cuid = new->uid = current->euid;
- new->gid = new->cgid = current->egid;
+ current_euid_egid(&euid, &egid);
+ new->cuid = new->uid = euid;
+ new->gid = new->cgid = egid;
new->seq = ids->seq++;
if(ids->seq > ids->seq_max)
@@ -616,13 +619,15 @@
int ipcperms (struct kern_ipc_perm *ipcp, short flag)
{ /* flag will most probably be 0 or S_...UGO from <linux/stat.h> */
+ uid_t euid = current_euid();
int requested_mode, granted_mode, err;
if (unlikely((err = audit_ipc_obj(ipcp))))
return err;
requested_mode = (flag >> 6) | (flag >> 3) | flag;
granted_mode = ipcp->mode;
- if (current->euid == ipcp->cuid || current->euid == ipcp->uid)
+ if (euid == ipcp->cuid ||
+ euid == ipcp->uid)
granted_mode >>= 6;
else if (in_group_p(ipcp->cgid) || in_group_p(ipcp->gid))
granted_mode >>= 3;
@@ -784,6 +789,7 @@
struct ipc64_perm *perm, int extra_perm)
{
struct kern_ipc_perm *ipcp;
+ uid_t euid;
int err;
down_write(&ids->rw_mutex);
@@ -803,8 +809,10 @@
if (err)
goto out_unlock;
}
- if (current->euid == ipcp->cuid ||
- current->euid == ipcp->uid || capable(CAP_SYS_ADMIN))
+
+ euid = current_euid();
+ if (euid == ipcp->cuid ||
+ euid == ipcp->uid || capable(CAP_SYS_ADMIN))
return ipcp;
err = -EPERM;