The patch titled
Subject: ipc: IPCMNI limit check for semmni
has been added to the -mm tree. Its filename is
ipc-ipcmni-limit-check-for-semmni.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/ipc-ipcmni-limit-check-for-semmni.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/ipc-ipcmni-limit-check-for-semmni.patch
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*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Waiman Long <longman@xxxxxxxxxx>
Subject: ipc: IPCMNI limit check for semmni
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.
Link: http://lkml.kernel.org/r/1536352137-12003-3-git-send-email-longman@xxxxxxxxxx
Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
Reviewed-by: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Luis R. Rodriguez <mcgrof@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
ipc/ipc_sysctl.c | 23 ++++++++++++++++++++++-
ipc/util.h | 9 +++++++++
2 files changed, 31 insertions(+), 1 deletion(-)
--- a/ipc/ipc_sysctl.c~ipc-ipcmni-limit-check-for-semmni
+++ a/ipc/ipc_sysctl.c
@@ -88,12 +88,33 @@ static int proc_ipc_auto_msgmni(struct c
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 struct ctl_table ipc_kern_table[]
.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
{
--- a/ipc/util.h~ipc-ipcmni-limit-check-for-semmni
+++ a/ipc/util.h
@@ -217,6 +217,15 @@ int ipcget(struct ipc_namespace *ns, str
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 {
_
Patches currently in -mm which might be from longman@xxxxxxxxxx are
list_lru-prefetch-neighboring-list-entries-before-acquiring-lock.patch
ipc-ipcmni-limit-check-for-msgmni-and-shmmni.patch
ipc-ipcmni-limit-check-for-semmni.patch
ipc-allow-boot-time-extension-of-ipcmni-from-32k-to-8m.patch
ipc-conserve-sequence-numbers-in-extended-ipcmni-mode.patch
