CRED: Wrap task credential accesses in the core kernel
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>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-audit@redhat.com
Cc: containers@lists.linux-foundation.org
Cc: linux-mm@kvack.org
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 36f4257..07a9647 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1115,6 +1115,7 @@
nodemask_t old;
nodemask_t new;
nodemask_t task_nodes;
+ uid_t uid, euid;
int err;
err = get_nodes(&old, old_nodes, maxnode);
@@ -1144,8 +1145,10 @@
* capabilities, superuser privileges or the same
* userid as the target process.
*/
- if ((current->euid != task->suid) && (current->euid != task->uid) &&
- (current->uid != task->suid) && (current->uid != task->uid) &&
+ uid = current_uid();
+ euid = current_euid();
+ if (euid != task->suid && euid != task->uid &&
+ uid != task->suid && uid != task->uid &&
!capable(CAP_SYS_NICE)) {
err = -EPERM;
goto out;
diff --git a/mm/migrate.c b/mm/migrate.c
index 6602941b..6263c24 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1048,6 +1048,7 @@
struct task_struct *task;
struct mm_struct *mm;
int err;
+ uid_t uid, euid;
/* Check flags */
if (flags & ~(MPOL_MF_MOVE|MPOL_MF_MOVE_ALL))
@@ -1075,8 +1076,10 @@
* capabilities, superuser privileges or the same
* userid as the target process.
*/
- if ((current->euid != task->suid) && (current->euid != task->uid) &&
- (current->uid != task->suid) && (current->uid != task->uid) &&
+ uid = current_uid();
+ euid = current_euid();
+ if (euid != task->suid && euid != task->uid &&
+ uid != task->suid && uid != task->uid &&
!capable(CAP_SYS_NICE)) {
err = -EPERM;
goto out;
diff --git a/mm/shmem.c b/mm/shmem.c
index 0ed0752..f1b0d48 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1513,8 +1513,8 @@
inode = new_inode(sb);
if (inode) {
inode->i_mode = mode;
- inode->i_uid = current->fsuid;
- inode->i_gid = current->fsgid;
+ inode->i_uid = current_fsuid();
+ inode->i_gid = current_fsgid();
inode->i_blocks = 0;
inode->i_mapping->backing_dev_info = &shmem_backing_dev_info;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
@@ -2278,8 +2278,8 @@
sbinfo->max_blocks = 0;
sbinfo->max_inodes = 0;
sbinfo->mode = S_IRWXUGO | S_ISVTX;
- sbinfo->uid = current->fsuid;
- sbinfo->gid = current->fsgid;
+ sbinfo->uid = current_fsuid();
+ sbinfo->gid = current_fsgid();
sbinfo->mpol = NULL;
sb->s_fs_info = sbinfo;