[PATCH v6 05/10] ipc: add new MSG_SET command for sys_msgctl() call
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> --- include/uapi/linux/msg.h | 1 + ipc/compat.c | 1 + ipc/msg.c | 13 +++++++++++-- security/selinux/hooks.c | 1 + security/smack/smack_lsm.c | 1 + 5 files changed, 15 insertions(+), 2 deletions(-) diff --git a/include/uapi/linux/msg.h b/include/uapi/linux/msg.h index 78dbd2f..76999c9 100644 --- a/include/uapi/linux/msg.h +++ b/include/uapi/linux/msg.h @@ -6,6 +6,7 @@ /* ipcs ctl commands */ #define MSG_STAT 11 #define MSG_INFO 12 +#define MSG_SET 13 /* 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; case IPC_SET: + case MSG_SET: if (version == IPC_64) { err = get_compat_msqid64(&m64, uptr); } else { diff --git a/ipc/msg.c b/ipc/msg.c index 2f44946..68515dc 100644 --- a/ipc/msg.c +++ b/ipc/msg.c @@ -392,6 +392,9 @@ copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version) out->msg_perm.uid = tbuf_old.msg_perm.uid; out->msg_perm.gid = tbuf_old.msg_perm.gid; out->msg_perm.mode = tbuf_old.msg_perm.mode; + out->msg_perm.cuid = tbuf_old.msg_perm.cuid; + out->msg_perm.cgid = tbuf_old.msg_perm.cgid; + out->msg_perm.key = tbuf_old.msg_perm.key; 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;
Re: [PATCH v6 05/10] ipc: add new MSG_SET command for sys_msgctl() call
Quoting Stanislav Kinsbursky (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> Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com> > --- > include/uapi/linux/msg.h | 1 + > ipc/compat.c | 1 + > ipc/msg.c | 13 +++++++++++-- > security/selinux/hooks.c | 1 + > security/smack/smack_lsm.c | 1 + > 5 files changed, 15 insertions(+), 2 deletions(-) > > diff --git a/include/uapi/linux/msg.h b/include/uapi/linux/msg.h > index 78dbd2f..76999c9 100644 > --- a/include/uapi/linux/msg.h > +++ b/include/uapi/linux/msg.h > @@ -6,6 +6,7 @@ > /* ipcs ctl commands */ > #define MSG_STAT 11 > #define MSG_INFO 12 > +#define MSG_SET 13 > > /* 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; > > case IPC_SET: > + case MSG_SET: > if (version == IPC_64) { > err = get_compat_msqid64(&m64, uptr); > } else { > diff --git a/ipc/msg.c b/ipc/msg.c > index 2f44946..68515dc 100644 > --- a/ipc/msg.c > +++ b/ipc/msg.c > @@ -392,6 +392,9 @@ copy_msqid_from_user(struct msqid64_ds *out, void __user *buf, int version) > out->msg_perm.uid = tbuf_old.msg_perm.uid; > out->msg_perm.gid = tbuf_old.msg_perm.gid; > out->msg_perm.mode = tbuf_old.msg_perm.mode; > + out->msg_perm.cuid = tbuf_old.msg_perm.cuid; > + out->msg_perm.cgid = tbuf_old.msg_perm.cgid; > + out->msg_perm.key = tbuf_old.msg_perm.key; > > 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; > > -- > To unsubscribe from this list: send the line "unsubscribe linux-security-module" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html