From: Davidlohr Bueso <dave@stgolabs.net>
To: Waiman Long <longman@redhat.com>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>,
Kees Cook <keescook@chromium.org>,
Andrew Morton <akpm@linux-foundation.org>,
Jonathan Corbet <corbet@lwn.net>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-doc@vger.kernel.org, Al Viro <viro@zeniv.linux.org.uk>,
Matthew Wilcox <willy@infradead.org>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Takashi Iwai <tiwai@suse.de>, Davidlohr Bueso <dbueso@suse.de>,
manfred@colorfullife.com
Subject: Re: [PATCH v8 2/5] ipc: IPCMNI limit check for semmni
Date: Fri, 17 Aug 2018 09:53:34 -0700 [thread overview]
Message-ID: <20180817165334.GA3677@linux-r8p5> (raw)
In-Reply-To: <1529317698-16575-3-git-send-email-longman@redhat.com>
On Mon, 18 Jun 2018, Waiman Long wrote:
>For SysV semaphores, the semmni value is the last part of the 4-element
>sem number array. To make semmni behave in a similar way to msgmni and
>shmmni, we can't directly use the _minmax handler. Instead, a special
>sem specific handler is added to check the last argument to make sure
>that it is limited to the [0, IPCMNI] range. An error will be returned
>if this is not the case.
>
>Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
>---
> ipc/ipc_sysctl.c | 23 ++++++++++++++++++++++-
> ipc/util.h | 9 +++++++++
> 2 files changed, 31 insertions(+), 1 deletion(-)
>
>diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
>index f87cb29..49f9bf4 100644
>--- a/ipc/ipc_sysctl.c
>+++ b/ipc/ipc_sysctl.c
>@@ -88,12 +88,33 @@ static int proc_ipc_auto_msgmni(struct ctl_table *table, int write,
> return proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
> }
>
>+static int proc_ipc_sem_dointvec(struct ctl_table *table, int write,
>+ void __user *buffer, size_t *lenp, loff_t *ppos)
>+{
>+ int ret, semmni;
>+ struct ipc_namespace *ns = current->nsproxy->ipc_ns;
>+
>+ semmni = ns->sem_ctls[3];
>+ ret = proc_ipc_dointvec(table, write, buffer, lenp, ppos);
>+
>+ if (!ret)
>+ ret = sem_check_semmni(current->nsproxy->ipc_ns);
>+
>+ /*
>+ * Reset the semmni value if an error happens.
>+ */
>+ if (ret)
>+ ns->sem_ctls[3] = semmni;
>+ return ret;
>+}
>+
> #else
> #define proc_ipc_doulongvec_minmax NULL
> #define proc_ipc_dointvec NULL
> #define proc_ipc_dointvec_minmax NULL
> #define proc_ipc_dointvec_minmax_orphans NULL
> #define proc_ipc_auto_msgmni NULL
>+#define proc_ipc_sem_dointvec NULL
> #endif
>
> static int zero;
>@@ -175,7 +196,7 @@ static int proc_ipc_auto_msgmni(struct ctl_table *table, int write,
> .data = &init_ipc_ns.sem_ctls,
> .maxlen = 4*sizeof(int),
> .mode = 0644,
>- .proc_handler = proc_ipc_dointvec,
>+ .proc_handler = proc_ipc_sem_dointvec,
> },
> #ifdef CONFIG_CHECKPOINT_RESTORE
> {
>diff --git a/ipc/util.h b/ipc/util.h
>index 0aba323..8e9c52c 100644
>--- a/ipc/util.h
>+++ b/ipc/util.h
>@@ -218,6 +218,15 @@ int ipcget(struct ipc_namespace *ns, struct ipc_ids *ids,
> void free_ipcs(struct ipc_namespace *ns, struct ipc_ids *ids,
> void (*free)(struct ipc_namespace *, struct kern_ipc_perm *));
>
>+static inline int sem_check_semmni(struct ipc_namespace *ns) {
>+ /*
>+ * Check semmni range [0, IPCMNI]
>+ * semmni is the last element of sem_ctls[4] array
>+ */
>+ return ((ns->sem_ctls[3] < 0) || (ns->sem_ctls[3] > IPCMNI))
>+ ? -ERANGE : 0;
>+}
>+
> #ifdef CONFIG_COMPAT
> #include <linux/compat.h>
> struct compat_ipc_perm {
>--
>1.8.3.1
>
next prev parent reply other threads:[~2018-08-17 19:57 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-06-18 10:28 [PATCH v8 0/5] ipc: IPCMNI limit check for *mni & increase that limit Waiman Long
2018-06-18 10:28 ` [PATCH v8 1/5] ipc: IPCMNI limit check for msgmni and shmmni Waiman Long
2018-06-28 3:16 ` Luis R. Rodriguez
2018-08-17 16:51 ` Davidlohr Bueso
2018-06-18 10:28 ` [PATCH v8 2/5] ipc: IPCMNI limit check for semmni Waiman Long
2018-06-28 22:39 ` Luis R. Rodriguez
2018-06-29 7:26 ` Waiman Long
2018-08-17 16:53 ` Davidlohr Bueso [this message]
2018-06-18 10:28 ` [PATCH v8 3/5] ipc: Allow boot time extension of IPCMNI from 32k to 2M Waiman Long
2018-08-17 16:45 ` Davidlohr Bueso
2018-08-18 1:15 ` Waiman Long
2018-10-02 16:32 ` Manfred Spraul
2018-10-02 17:43 ` Waiman Long
2018-06-18 10:28 ` [PATCH v8 4/5] ipc: Conserve sequence numbers in extended IPCMNI mode Waiman Long
2018-06-18 10:28 ` [PATCH v8 5/5] ipc: Add a new ipcmni_compat sysctl to fall back to old behavior Waiman Long
2018-06-18 11:36 ` kbuild test robot
2018-06-18 14:27 ` kbuild test robot
2018-08-17 16:50 ` [PATCH v8 0/5] ipc: IPCMNI limit check for *mni & increase that limit Davidlohr Bueso
2018-09-06 22:24 ` Andrew Morton
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