[PATCH] sysctl: implement sysctl_uts_string()
The problem: When using sys_sysctl we don't read the proper values for the
variables exported from the uts namespace, nor do we do the proper locking.
This patch introduces sysctl_uts_string which properly fetches the values and
does the proper locking.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index c8bcbfb..77ea4fc 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -137,6 +137,10 @@
static int proc_do_uts_string(ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos);
+static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen,
+ void __user *oldval, size_t __user *oldlenp,
+ void __user *newval, size_t newlen, void **context);
+
#ifdef CONFIG_PROC_SYSCTL
static int proc_do_cad_pid(ctl_table *table, int write, struct file *filp,
void __user *buffer, size_t *lenp, loff_t *ppos);
@@ -258,7 +262,7 @@
.maxlen = sizeof(init_uts_ns.name.sysname),
.mode = 0444,
.proc_handler = &proc_do_uts_string,
- .strategy = &sysctl_string,
+ .strategy = &sysctl_uts_string,
},
{
.ctl_name = KERN_OSRELEASE,
@@ -267,7 +271,7 @@
.maxlen = sizeof(init_uts_ns.name.release),
.mode = 0444,
.proc_handler = &proc_do_uts_string,
- .strategy = &sysctl_string,
+ .strategy = &sysctl_uts_string,
},
{
.ctl_name = KERN_VERSION,
@@ -276,7 +280,7 @@
.maxlen = sizeof(init_uts_ns.name.version),
.mode = 0444,
.proc_handler = &proc_do_uts_string,
- .strategy = &sysctl_string,
+ .strategy = &sysctl_uts_string,
},
{
.ctl_name = KERN_NODENAME,
@@ -285,7 +289,7 @@
.maxlen = sizeof(init_uts_ns.name.nodename),
.mode = 0644,
.proc_handler = &proc_do_uts_string,
- .strategy = &sysctl_string,
+ .strategy = &sysctl_uts_string,
},
{
.ctl_name = KERN_DOMAINNAME,
@@ -294,7 +298,7 @@
.maxlen = sizeof(init_uts_ns.name.domainname),
.mode = 0644,
.proc_handler = &proc_do_uts_string,
- .strategy = &sysctl_string,
+ .strategy = &sysctl_uts_string,
},
{
.ctl_name = KERN_PANIC,
@@ -2598,6 +2602,23 @@
return 1;
}
+
+/* The generic string strategy routine: */
+static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen,
+ void __user *oldval, size_t __user *oldlenp,
+ void __user *newval, size_t newlen, void **context)
+{
+ struct ctl_table uts_table;
+ int r, write;
+ write = newval && newlen;
+ memcpy(&uts_table, table, sizeof(uts_table));
+ uts_table.data = get_uts(table, write);
+ r = sysctl_string(&uts_table, name, nlen,
+ oldval, oldlenp, newval, newlen, context);
+ put_uts(table, write, uts_table.data);
+ return r;
+}
+
#else /* CONFIG_SYSCTL_SYSCALL */
@@ -2662,6 +2683,12 @@
return -ENOSYS;
}
+static int sysctl_uts_string(ctl_table *table, int __user *name, int nlen,
+ void __user *oldval, size_t __user *oldlenp,
+ void __user *newval, size_t newlen, void **context)
+{
+ return -ENOSYS;
+}
#endif /* CONFIG_SYSCTL_SYSCALL */
/*