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[PATCH v6 05/10] ipc: add new MSG_SET command for sys_msgctl() call
https://new-forum.openvz.org/index.phpindex.php?t=rview&goto=48353&th=11201#msg_48353
update key, cuid and cgid values. IOW, it allows to change existent key value.
The fact, that key is not used is checked before update. Otherwise -EEXIST is
returned.
/* msgrcv options */
#define MSG_NOERROR 010000 /* no error if message is too big */
diff --git a/ipc/compat.c b/ipc/compat.c
index 35c750d..9c70f9a 100644
--- a/ipc/compat.c
+++ b/ipc/compat.c
@@ -483,6 +483,7 @@ long compat_sys_msgctl(int first, int second, void __user *uptr)
break;
if (tbuf_old.msg_qbytes == 0)
out->msg_qbytes = tbuf_old.msg_lqbytes;
@@ -418,12 +421,13 @@ static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
struct msg_queue *msq;
int err;
- if (cmd == IPC_SET) {
+ if (cmd == IPC_SET || cmd == MSG_SET) {
if (copy_msqid_from_user(&msqid64, buf, version))
return -EFAULT;
}
- ipcp = ipcctl_pre_down(ns, &msg_ids(ns), msqid, cmd,
+ ipcp = ipcctl_pre_down(ns, &msg_ids(ns), msqid,
+ (cmd != MSG_SET) ? cmd : IPC_SET,
&msqid64.msg_perm, msqid64.msg_qbytes);
if (IS_ERR(ipcp))
return PTR_ERR(ipcp);
@@ -439,6 +443,7 @@ static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
freeque(ns, ipcp);
goto out_up;
case IPC_SET:
+ case MSG_SET:
if (msqid64.msg_qbytes > ns->msg_ctlmnb &&
!capable(CAP_SYS_RESOURCE)) {
err = -EPERM;
@@ -451,6 +456,9 @@ static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
msq->q_qbytes = msqid64.msg_qbytes;
+ if (cmd == MSG_SET)
+ ipc_update_key(&msg_ids(ns), &msqid64.msg_perm, ipcp);
+
msq->q_ctime = get_seconds();
/* sleeping receivers might be excluded by
* stricter permissions.
@@ -569,6 +577,7 @@ SYSCALL_DEFINE3(msgctl, int, msqid, int, cmd, struct msqid_ds __user *, buf)
}
case IPC_SET:
case IPC_RMID:
+ case MSG_SET:
err = msgctl_down(ns, msqid, cmd, buf, version);
return err;
default:
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 62b2447..78b77ac 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -4885,6 +4885,7 @@ static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd)
perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
break;
case IPC_SET:
+ case MSG_SET:
perms = MSGQ__SETATTR;
break;
case IPC_RMID:
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index c7eabc9..d51a8da 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -2374,6 +2374,7 @@ static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
may = MAY_READ;
break;
case IPC_SET:
+ case MSG_SET:
case IPC_RMID:
may = MAY_READWRITE;
break;]]>Stanislav Kinsbursky2012-10-15T16:00:01-00:00Re: [PATCH v6 05/10] ipc: add new MSG_SET command for sys_msgctl() call
https://new-forum.openvz.org/index.phpindex.php?t=rview&goto=48569&th=11201#msg_48569
skinsbursky@parallels.com):
> New MSG_SET command will be interpreted exactly as IPC_SET, but also will
> update key, cuid and cgid values. IOW, it allows to change existent key value.
> The fact, that key is not used is checked before update. Otherwise -EEXIST is
> returned.
>
> Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>