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authorMathias Krause <minipli@googlemail.com>2013-11-03 12:36:28 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-03 10:53:11 -0800
commit9bf76ca325d5e9208eb343f7bd4cc666f703ed30 (patch)
tree0c6e992844c24162838013caa4f4f3356d6594dd
parent9dc8c89dfbbac5546101379d8d2aa0fa30d39888 (diff)
downloadlinux-9bf76ca325d5e9208eb343f7bd4cc666f703ed30.tar.gz
ipc, msg: forbid negative values for "msg{max,mnb,mni}"
Negative message lengths make no sense -- so don't do negative queue lenghts or identifier counts. Prevent them from getting negative. Also change the underlying data types to be unsigned to avoid hairy surprises with sign extensions in cases where those variables get evaluated in unsigned expressions with bigger data types, e.g size_t. In case a user still wants to have "unlimited" sizes she could just use INT_MAX instead. Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/ipc_namespace.h6
-rw-r--r--ipc/ipc_sysctl.c20
2 files changed, 15 insertions, 11 deletions
diff --git a/include/linux/ipc_namespace.h b/include/linux/ipc_namespace.h
index 19c19a5eee2..f6c82de1254 100644
--- a/include/linux/ipc_namespace.h
+++ b/include/linux/ipc_namespace.h
@@ -34,9 +34,9 @@ struct ipc_namespace {
int sem_ctls[4];
int used_sems;
- int msg_ctlmax;
- int msg_ctlmnb;
- int msg_ctlmni;
+ unsigned int msg_ctlmax;
+ unsigned int msg_ctlmnb;
+ unsigned int msg_ctlmni;
atomic_t msg_bytes;
atomic_t msg_hdrs;
int auto_msgmni;
diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c
index 130dfece27a..b0e99deb6d0 100644
--- a/ipc/ipc_sysctl.c
+++ b/ipc/ipc_sysctl.c
@@ -62,7 +62,7 @@ static int proc_ipc_dointvec_minmax_orphans(ctl_table *table, int write,
return err;
}
-static int proc_ipc_callback_dointvec(ctl_table *table, int write,
+static int proc_ipc_callback_dointvec_minmax(ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos)
{
struct ctl_table ipc_table;
@@ -72,7 +72,7 @@ static int proc_ipc_callback_dointvec(ctl_table *table, int write,
memcpy(&ipc_table, table, sizeof(ipc_table));
ipc_table.data = get_ipc(table);
- rc = proc_dointvec(&ipc_table, write, buffer, lenp, ppos);
+ rc = proc_dointvec_minmax(&ipc_table, write, buffer, lenp, ppos);
if (write && !rc && lenp_bef == *lenp)
/*
@@ -152,15 +152,13 @@ static int proc_ipcauto_dointvec_minmax(ctl_table *table, int write,
#define proc_ipc_dointvec NULL
#define proc_ipc_dointvec_minmax NULL
#define proc_ipc_dointvec_minmax_orphans NULL
-#define proc_ipc_callback_dointvec NULL
+#define proc_ipc_callback_dointvec_minmax NULL
#define proc_ipcauto_dointvec_minmax NULL
#endif
static int zero;
static int one = 1;
-#ifdef CONFIG_CHECKPOINT_RESTORE
static int int_max = INT_MAX;
-#endif
static struct ctl_table ipc_kern_table[] = {
{
@@ -198,21 +196,27 @@ static struct ctl_table ipc_kern_table[] = {
.data = &init_ipc_ns.msg_ctlmax,
.maxlen = sizeof (init_ipc_ns.msg_ctlmax),
.mode = 0644,
- .proc_handler = proc_ipc_dointvec,
+ .proc_handler = proc_ipc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &int_max,
},
{
.procname = "msgmni",
.data = &init_ipc_ns.msg_ctlmni,
.maxlen = sizeof (init_ipc_ns.msg_ctlmni),
.mode = 0644,
- .proc_handler = proc_ipc_callback_dointvec,
+ .proc_handler = proc_ipc_callback_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &int_max,
},
{
.procname = "msgmnb",
.data = &init_ipc_ns.msg_ctlmnb,
.maxlen = sizeof (init_ipc_ns.msg_ctlmnb),
.mode = 0644,
- .proc_handler = proc_ipc_dointvec,
+ .proc_handler = proc_ipc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &int_max,
},
{
.procname = "sem",