The patch titled
Subject: ipc/: clamp semmni to the real IPCMNI limit
has been added to the -mm tree. Its filename is
ipc-clamp-semmni-to-the-real-ipcmni-limit.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/ipc-clamp-semmni-to-the-real-ipcmni-limit.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/ipc-clamp-semmni-to-the-real-ipcmni-limit.patch
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------------------------------------------------------
From: Waiman Long <longman@xxxxxxxxxx>
Subject: ipc/: clamp semmni to the real IPCMNI limit
Clamp the semmni value (fourth element of sem_ctls[] array) to within the
[0, IPCMNI] range and print a warning message once when an out-of-range
value is being written.
Link: http://lkml.kernel.org/r/1519926220-7453-7-git-send-email-longman@xxxxxxxxxx
Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Davidlohr Bueso <dave@xxxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: "Luis R. Rodriguez" <mcgrof@xxxxxxxxxx>
Cc: Manfred Spraul <manfred@xxxxxxxxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
ipc/ipc_sysctl.c | 13 ++++++++++++-
ipc/sem.c | 28 ++++++++++++++++++++++++++++
ipc/util.h | 4 ++++
3 files changed, 44 insertions(+), 1 deletion(-)
diff -puN ipc/ipc_sysctl.c~ipc-clamp-semmni-to-the-real-ipcmni-limit ipc/ipc_sysctl.c
--- a/ipc/ipc_sysctl.c~ipc-clamp-semmni-to-the-real-ipcmni-limit
+++ a/ipc/ipc_sysctl.c
@@ -97,12 +97,22 @@ 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 = proc_ipc_dointvec(table, write, buffer, lenp, ppos);
+
+ sem_check_semmni(table, current->nsproxy->ipc_ns);
+ 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;
@@ -186,7 +196,8 @@ 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,
+ .flags = CTL_FLAGS_CLAMP_RANGE,
},
#ifdef CONFIG_CHECKPOINT_RESTORE
{
diff -puN ipc/sem.c~ipc-clamp-semmni-to-the-real-ipcmni-limit ipc/sem.c
--- a/ipc/sem.c~ipc-clamp-semmni-to-the-real-ipcmni-limit
+++ a/ipc/sem.c
@@ -2344,3 +2344,31 @@ static int sysvipc_sem_proc_show(struct
return 0;
}
#endif
+
+#ifdef CONFIG_PROC_SYSCTL
+/*
+ * Check to see if semmni is out of range and clamp it if necessary.
+ */
+void sem_check_semmni(struct ctl_table *table, struct ipc_namespace *ns)
+{
+ bool clamped = false;
+
+ if (!(table->flags & CTL_FLAGS_CLAMP_RANGE))
+ return;
+
+ /*
+ * Clamp semmni to the range [0, IPCMNI].
+ */
+ if (ns->sc_semmni < 0) {
+ ns->sc_semmni = 0;
+ clamped = true;
+ }
+ if (ns->sc_semmni > IPCMNI) {
+ ns->sc_semmni = IPCMNI;
+ clamped = true;
+ }
+ if (clamped)
+ pr_warn_once("Kernel parameter \"sem[3]\" was set out of range [%d, %d], clamped to %d.\n",
+ 0, IPCMNI, ns->sc_semmni);
+}
+#endif
diff -puN ipc/util.h~ipc-clamp-semmni-to-the-real-ipcmni-limit ipc/util.h
--- a/ipc/util.h~ipc-clamp-semmni-to-the-real-ipcmni-limit
+++ a/ipc/util.h
@@ -206,6 +206,10 @@ 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 *));
+#ifdef CONFIG_PROC_SYSCTL
+extern void sem_check_semmni(struct ctl_table *table, struct ipc_namespace *ns);
+#endif
+
#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
proc-sysctl-fix-typo-in-sysctl_check_table_array.patch
sysctl-add-kdoc-comments-to-do_proc_douintvec_minmax_conv_param.patch
sysctl-add-flags-to-support-min-max-range-clamping.patch
sysctl-warn-when-a-clamped-sysctl-parameter-is-set-out-of-range.patch
ipc-clamp-msgmni-and-shmmni-to-the-real-ipcmni-limit.patch
ipc-clamp-semmni-to-the-real-ipcmni-limit.patch
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