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>
This commit is contained in:
David Howells 2008-11-14 10:39:06 +11:00 committed by James Morris
parent da9592edeb
commit 414c0708d0
3 changed files with 19 additions and 10 deletions

View file

@ -117,8 +117,8 @@ static struct inode *mqueue_get_inode(struct super_block *sb, int mode,
inode = new_inode(sb); inode = new_inode(sb);
if (inode) { if (inode) {
inode->i_mode = mode; inode->i_mode = mode;
inode->i_uid = current->fsuid; inode->i_uid = current_fsuid();
inode->i_gid = current->fsgid; inode->i_gid = current_fsgid();
inode->i_blocks = 0; inode->i_blocks = 0;
inode->i_mtime = inode->i_ctime = inode->i_atime = inode->i_mtime = inode->i_ctime = inode->i_atime =
CURRENT_TIME; CURRENT_TIME;
@ -507,7 +507,7 @@ static void __do_notify(struct mqueue_inode_info *info)
sig_i.si_code = SI_MESGQ; sig_i.si_code = SI_MESGQ;
sig_i.si_value = info->notify.sigev_value; sig_i.si_value = info->notify.sigev_value;
sig_i.si_pid = task_tgid_vnr(current); sig_i.si_pid = task_tgid_vnr(current);
sig_i.si_uid = current->uid; sig_i.si_uid = current_uid();
kill_pid_info(info->notify.sigev_signo, kill_pid_info(info->notify.sigev_signo,
&sig_i, info->notify_owner); &sig_i, info->notify_owner);

View file

@ -752,9 +752,10 @@ asmlinkage long sys_shmctl(int shmid, int cmd, struct shmid_ds __user *buf)
goto out_unlock; goto out_unlock;
if (!capable(CAP_IPC_LOCK)) { if (!capable(CAP_IPC_LOCK)) {
uid_t euid = current_euid();
err = -EPERM; err = -EPERM;
if (current->euid != shp->shm_perm.uid && if (euid != shp->shm_perm.uid &&
current->euid != shp->shm_perm.cuid) euid != shp->shm_perm.cuid)
goto out_unlock; goto out_unlock;
if (cmd == SHM_LOCK && if (cmd == SHM_LOCK &&
!current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur) !current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur)

View file

@ -258,6 +258,8 @@ int ipc_get_maxid(struct ipc_ids *ids)
int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size) int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
{ {
uid_t euid;
gid_t egid;
int id, err; int id, err;
if (size > IPCMNI) if (size > IPCMNI)
@ -272,8 +274,9 @@ int ipc_addid(struct ipc_ids* ids, struct kern_ipc_perm* new, int size)
ids->in_use++; ids->in_use++;
new->cuid = new->uid = current->euid; current_euid_egid(&euid, &egid);
new->gid = new->cgid = current->egid; new->cuid = new->uid = euid;
new->gid = new->cgid = egid;
new->seq = ids->seq++; new->seq = ids->seq++;
if(ids->seq > ids->seq_max) if(ids->seq > ids->seq_max)
@ -616,13 +619,15 @@ void ipc_rcu_putref(void *ptr)
int ipcperms (struct kern_ipc_perm *ipcp, short flag) int ipcperms (struct kern_ipc_perm *ipcp, short flag)
{ /* flag will most probably be 0 or S_...UGO from <linux/stat.h> */ { /* flag will most probably be 0 or S_...UGO from <linux/stat.h> */
uid_t euid = current_euid();
int requested_mode, granted_mode, err; int requested_mode, granted_mode, err;
if (unlikely((err = audit_ipc_obj(ipcp)))) if (unlikely((err = audit_ipc_obj(ipcp))))
return err; return err;
requested_mode = (flag >> 6) | (flag >> 3) | flag; requested_mode = (flag >> 6) | (flag >> 3) | flag;
granted_mode = ipcp->mode; granted_mode = ipcp->mode;
if (current->euid == ipcp->cuid || current->euid == ipcp->uid) if (euid == ipcp->cuid ||
euid == ipcp->uid)
granted_mode >>= 6; granted_mode >>= 6;
else if (in_group_p(ipcp->cgid) || in_group_p(ipcp->gid)) else if (in_group_p(ipcp->cgid) || in_group_p(ipcp->gid))
granted_mode >>= 3; granted_mode >>= 3;
@ -784,6 +789,7 @@ struct kern_ipc_perm *ipcctl_pre_down(struct ipc_ids *ids, int id, int cmd,
struct ipc64_perm *perm, int extra_perm) struct ipc64_perm *perm, int extra_perm)
{ {
struct kern_ipc_perm *ipcp; struct kern_ipc_perm *ipcp;
uid_t euid;
int err; int err;
down_write(&ids->rw_mutex); down_write(&ids->rw_mutex);
@ -803,8 +809,10 @@ struct kern_ipc_perm *ipcctl_pre_down(struct ipc_ids *ids, int id, int cmd,
if (err) if (err)
goto out_unlock; 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; return ipcp;
err = -EPERM; err = -EPERM;