path: root/ipc/msg.c
diff options
authorLinus Torvalds <torvalds@linux-foundation.org>2018-04-03 19:15:32 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-04-03 19:15:32 -0700
commit17dec0a949153d9ac00760ba2f5b78cb583e995f (patch)
treeaaf44fee3aca81a86ecfa46f3f409d5cf5675f1f /ipc/msg.c
parentMerge branch 'for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq (diff)
parentipc/shm: Fix pid freeing. (diff)
Merge branch 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull namespace updates from Eric Biederman: "There was a lot of work this cycle fixing bugs that were discovered after the merge window and getting everything ready where we can reasonably support fully unprivileged fuse. The bug fixes you already have and much of the unprivileged fuse work is coming in via other trees. Still left for fully unprivileged fuse is figuring out how to cleanly handle .set_acl and .get_acl in the legacy case, and properly handling of evm xattrs on unprivileged mounts. Included in the tree is a cleanup from Alexely that replaced a linked list with a statically allocated fix sized array for the pid caches, which simplifies and speeds things up. Then there is are some cleanups and fixes for the ipc namespace. The motivation was that in reviewing other code it was discovered that access ipc objects from different pid namespaces recorded pids in such a way that when asked the wrong pids were returned. In the worst case there has been a measured 30% performance impact for sysvipc semaphores. Other test cases showed no measurable performance impact. Manfred Spraul and Davidlohr Bueso who tend to work on sysvipc performance both gave the nod that this is good enough. Casey Schaufler and James Morris have given their approval to the LSM side of the changes. I simplified the types and the code dealing with sysvipc to pass just kern_ipc_perm for all three types of ipc. Which reduced the header dependencies throughout the kernel and simplified the lsm code. Which let me work on the pid fixes without having to worry about trivial changes causing complete kernel recompiles" * 'userns-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: ipc/shm: Fix pid freeing. ipc/shm: fix up for struct file no longer being available in shm.h ipc/smack: Tidy up from the change in type of the ipc security hooks ipc: Directly call the security hook in ipc_ops.associate ipc/sem: Fix semctl(..., GETPID, ...) between pid namespaces ipc/msg: Fix msgctl(..., IPC_STAT, ...) between pid namespaces ipc/shm: Fix shmctl(..., IPC_STAT, ...) between pid namespaces. ipc/util: Helpers for making the sysvipc operations pid namespace aware ipc: Move IPCMNI from include/ipc.h into ipc/util.h msg: Move struct msg_queue into ipc/msg.c shm: Move struct shmid_kernel into ipc/shm.c sem: Move struct sem and struct sem_array into ipc/sem.c msg/security: Pass kern_ipc_perm not msg_queue into the msg_queue security hooks shm/security: Pass kern_ipc_perm not shmid_kernel into the shm security hooks sem/security: Pass kern_ipc_perm not sem_array into the sem security hooks pidns: simpler allocation of pid_* caches
Diffstat (limited to 'ipc/msg.c')
1 files changed, 36 insertions, 26 deletions
diff --git a/ipc/msg.c b/ipc/msg.c
index 9de48065c1ac..114a21189613 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -43,6 +43,23 @@
#include <linux/uaccess.h>
#include "util.h"
+/* one msq_queue structure for each present queue on the system */
+struct msg_queue {
+ struct kern_ipc_perm q_perm;
+ time64_t q_stime; /* last msgsnd time */
+ time64_t q_rtime; /* last msgrcv time */
+ time64_t q_ctime; /* last change time */
+ unsigned long q_cbytes; /* current number of bytes on queue */
+ unsigned long q_qnum; /* number of messages in queue */
+ unsigned long q_qbytes; /* max number of bytes on queue */
+ struct pid *q_lspid; /* pid of last msgsnd */
+ struct pid *q_lrpid; /* last receive pid */
+ struct list_head q_messages;
+ struct list_head q_receivers;
+ struct list_head q_senders;
+} __randomize_layout;
/* one msg_receiver structure for each sleeping receiver */
struct msg_receiver {
struct list_head r_list;
@@ -101,7 +118,7 @@ static void msg_rcu_free(struct rcu_head *head)
struct kern_ipc_perm *p = container_of(head, struct kern_ipc_perm, rcu);
struct msg_queue *msq = container_of(p, struct msg_queue, q_perm);
- security_msg_queue_free(msq);
+ security_msg_queue_free(&msq->q_perm);
@@ -127,7 +144,7 @@ static int newque(struct ipc_namespace *ns, struct ipc_params *params)
msq->q_perm.key = key;
msq->q_perm.security = NULL;
- retval = security_msg_queue_alloc(msq);
+ retval = security_msg_queue_alloc(&msq->q_perm);
if (retval) {
return retval;
@@ -137,7 +154,7 @@ static int newque(struct ipc_namespace *ns, struct ipc_params *params)
msq->q_ctime = ktime_get_real_seconds();
msq->q_cbytes = msq->q_qnum = 0;
msq->q_qbytes = ns->msg_ctlmnb;
- msq->q_lspid = msq->q_lrpid = 0;
+ msq->q_lspid = msq->q_lrpid = NULL;
@@ -250,25 +267,17 @@ static void freeque(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp)
atomic_sub(msq->q_cbytes, &ns->msg_bytes);
+ ipc_update_pid(&msq->q_lspid, NULL);
+ ipc_update_pid(&msq->q_lrpid, NULL);
ipc_rcu_putref(&msq->q_perm, msg_rcu_free);
- * Called with msg_ids.rwsem and ipcp locked.
- */
-static inline int msg_security(struct kern_ipc_perm *ipcp, int msgflg)
- struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
- return security_msg_queue_associate(msq, msgflg);
long ksys_msgget(key_t key, int msgflg)
struct ipc_namespace *ns;
static const struct ipc_ops msg_ops = {
.getnew = newque,
- .associate = msg_security,
+ .associate = security_msg_queue_associate,
struct ipc_params msg_params;
@@ -385,7 +394,7 @@ static int msgctl_down(struct ipc_namespace *ns, int msqid, int cmd,
msq = container_of(ipcp, struct msg_queue, q_perm);
- err = security_msg_queue_msgctl(msq, cmd);
+ err = security_msg_queue_msgctl(&msq->q_perm, cmd);
if (err)
goto out_unlock1;
@@ -507,7 +516,7 @@ static int msgctl_stat(struct ipc_namespace *ns, int msqid,
if (ipcperms(ns, &msq->q_perm, S_IRUGO))
goto out_unlock;
- err = security_msg_queue_msgctl(msq, cmd);
+ err = security_msg_queue_msgctl(&msq->q_perm, cmd);
if (err)
goto out_unlock;
@@ -526,8 +535,8 @@ static int msgctl_stat(struct ipc_namespace *ns, int msqid,
p->msg_cbytes = msq->q_cbytes;
p->msg_qnum = msq->q_qnum;
p->msg_qbytes = msq->q_qbytes;
- p->msg_lspid = msq->q_lspid;
- p->msg_lrpid = msq->q_lrpid;
+ p->msg_lspid = pid_vnr(msq->q_lspid);
+ p->msg_lrpid = pid_vnr(msq->q_lrpid);
@@ -733,7 +742,7 @@ static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg,
list_for_each_entry_safe(msr, t, &msq->q_receivers, r_list) {
if (testmsg(msg, msr->r_msgtype, msr->r_mode) &&
- !security_msg_queue_msgrcv(msq, msg, msr->r_tsk,
+ !security_msg_queue_msgrcv(&msq->q_perm, msg, msr->r_tsk,
msr->r_msgtype, msr->r_mode)) {
@@ -741,7 +750,7 @@ static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg,
wake_q_add(wake_q, msr->r_tsk);
WRITE_ONCE(msr->r_msg, ERR_PTR(-E2BIG));
} else {
- msq->q_lrpid = task_pid_vnr(msr->r_tsk);
+ ipc_update_pid(&msq->q_lrpid, task_pid(msr->r_tsk));
msq->q_rtime = get_seconds();
wake_q_add(wake_q, msr->r_tsk);
@@ -799,7 +808,7 @@ static long do_msgsnd(int msqid, long mtype, void __user *mtext,
goto out_unlock0;
- err = security_msg_queue_msgsnd(msq, msg, msgflg);
+ err = security_msg_queue_msgsnd(&msq->q_perm, msg, msgflg);
if (err)
goto out_unlock0;
@@ -842,7 +851,7 @@ static long do_msgsnd(int msqid, long mtype, void __user *mtext,
- msq->q_lspid = task_tgid_vnr(current);
+ ipc_update_pid(&msq->q_lspid, task_tgid(current));
msq->q_stime = get_seconds();
if (!pipelined_send(msq, msg, &wake_q)) {
@@ -987,7 +996,7 @@ static struct msg_msg *find_msg(struct msg_queue *msq, long *msgtyp, int mode)
list_for_each_entry(msg, &msq->q_messages, m_list) {
if (testmsg(msg, *msgtyp, mode) &&
- !security_msg_queue_msgrcv(msq, msg, current,
+ !security_msg_queue_msgrcv(&msq->q_perm, msg, current,
*msgtyp, mode)) {
if (mode == SEARCH_LESSEQUAL && msg->m_type != 1) {
*msgtyp = msg->m_type - 1;
@@ -1072,7 +1081,7 @@ static long do_msgrcv(int msqid, void __user *buf, size_t bufsz, long msgtyp, in
msq->q_rtime = get_seconds();
- msq->q_lrpid = task_tgid_vnr(current);
+ ipc_update_pid(&msq->q_lrpid, task_tgid(current));
msq->q_cbytes -= msg->m_ts;
atomic_sub(msg->m_ts, &ns->msg_bytes);
@@ -1227,6 +1236,7 @@ void msg_exit_ns(struct ipc_namespace *ns)
static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
+ struct pid_namespace *pid_ns = ipc_seq_pid_ns(s);
struct user_namespace *user_ns = seq_user_ns(s);
struct kern_ipc_perm *ipcp = it;
struct msg_queue *msq = container_of(ipcp, struct msg_queue, q_perm);
@@ -1238,8 +1248,8 @@ static int sysvipc_msg_proc_show(struct seq_file *s, void *it)
- msq->q_lspid,
- msq->q_lrpid,
+ pid_nr_ns(msq->q_lspid, pid_ns),
+ pid_nr_ns(msq->q_lrpid, pid_ns),
from_kuid_munged(user_ns, msq->q_perm.uid),
from_kgid_munged(user_ns, msq->q_perm.gid),
from_kuid_munged(user_ns, msq->q_perm.cuid),