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authorSerge E. Hallyn <serge@hallyn.com>2011-03-23 16:43:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-03-23 19:47:08 -0700
commitb0e77598f87107001a00b8a4ece9c95e4254ccc4 (patch)
tree2738276570e4faa7c92a64521c192f04dca93801 /ipc/util.c
parentuserns: add a user namespace owner of ipc ns (diff)
downloadlinux-dev-b0e77598f87107001a00b8a4ece9c95e4254ccc4.tar.xz
linux-dev-b0e77598f87107001a00b8a4ece9c95e4254ccc4.zip
userns: user namespaces: convert several capable() calls
CAP_IPC_OWNER and CAP_IPC_LOCK can be checked against current_user_ns(), because the resource comes from current's own ipc namespace. setuid/setgid are to uids in own namespace, so again checks can be against current_user_ns(). Changelog: Jan 11: Use task_ns_capable() in place of sched_capable(). Jan 11: Use nsown_capable() as suggested by Bastian Blank. Jan 11: Clarify (hopefully) some logic in futex and sched.c Feb 15: use ns_capable for ipc, not nsown_capable Feb 23: let copy_ipcs handle setting ipc_ns->user_ns Feb 23: pass ns down rather than taking it from current [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Daniel Lezcano <daniel.lezcano@free.fr> Acked-by: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'ipc/util.c')
-rw-r--r--ipc/util.c26
1 files changed, 16 insertions, 10 deletions
diff --git a/ipc/util.c b/ipc/util.c
index 69a0cc13d966..8fd1b891ec0c 100644
--- a/ipc/util.c
+++ b/ipc/util.c
@@ -329,12 +329,14 @@ retry:
*
* It is called with ipc_ids.rw_mutex and ipcp->lock held.
*/
-static int ipc_check_perms(struct kern_ipc_perm *ipcp, struct ipc_ops *ops,
- struct ipc_params *params)
+static int ipc_check_perms(struct ipc_namespace *ns,
+ struct kern_ipc_perm *ipcp,
+ struct ipc_ops *ops,
+ struct ipc_params *params)
{
int err;
- if (ipcperms(ipcp, params->flg))
+ if (ipcperms(ns, ipcp, params->flg))
err = -EACCES;
else {
err = ops->associate(ipcp, params->flg);
@@ -396,7 +398,7 @@ retry:
* ipc_check_perms returns the IPC id on
* success
*/
- err = ipc_check_perms(ipcp, ops, params);
+ err = ipc_check_perms(ns, ipcp, ops, params);
}
ipc_unlock(ipcp);
}
@@ -610,10 +612,12 @@ void ipc_rcu_putref(void *ptr)
*
* Check user, group, other permissions for access
* to ipc resources. return 0 if allowed
+ *
+ * @flag will most probably be 0 or S_...UGO from <linux/stat.h>
*/
-int ipcperms (struct kern_ipc_perm *ipcp, short flag)
-{ /* flag will most probably be 0 or S_...UGO from <linux/stat.h> */
+int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flag)
+{
uid_t euid = current_euid();
int requested_mode, granted_mode;
@@ -627,7 +631,7 @@ int ipcperms (struct kern_ipc_perm *ipcp, short flag)
granted_mode >>= 3;
/* is there some bit set in requested_mode but not in granted_mode? */
if ((requested_mode & ~granted_mode & 0007) &&
- !capable(CAP_IPC_OWNER))
+ !ns_capable(ns->user_ns, CAP_IPC_OWNER))
return -1;
return security_ipc_permission(ipcp, flag);
@@ -765,6 +769,7 @@ void ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out)
/**
* ipcctl_pre_down - retrieve an ipc and check permissions for some IPC_XXX cmd
+ * @ids: the ipc namespace
* @ids: the table of ids where to look for the ipc
* @id: the id of the ipc to retrieve
* @cmd: the cmd to check
@@ -779,7 +784,8 @@ void ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out)
* - returns the ipc with both ipc and rw_mutex locks held in case of success
* or an err-code without any lock held otherwise.
*/
-struct kern_ipc_perm *ipcctl_pre_down(struct ipc_ids *ids, int id, int cmd,
+struct kern_ipc_perm *ipcctl_pre_down(struct ipc_namespace *ns,
+ struct ipc_ids *ids, int id, int cmd,
struct ipc64_perm *perm, int extra_perm)
{
struct kern_ipc_perm *ipcp;
@@ -799,8 +805,8 @@ struct kern_ipc_perm *ipcctl_pre_down(struct ipc_ids *ids, int id, int cmd,
perm->gid, perm->mode);
euid = current_euid();
- if (euid == ipcp->cuid ||
- euid == ipcp->uid || capable(CAP_SYS_ADMIN))
+ if (euid == ipcp->cuid || euid == ipcp->uid ||
+ ns_capable(ns->user_ns, CAP_SYS_ADMIN))
return ipcp;
err = -EPERM;