[S390] call home: fix string length handling
After copying uts->nodename to the static nodename array the static
version isn't necessarily zero termininated, since the size of the
array is one byte too short.
Afterwards doing strncat(data, nodename, strlen(nodename)); may copy
an arbitrary large amount of bytes.
Fix this by getting rid of the static array and using strncat with
proper length limit.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/char/sclp_async.c b/drivers/s390/char/sclp_async.c
index 3c20aa1..b44462a 100644
--- a/drivers/s390/char/sclp_async.c
+++ b/drivers/s390/char/sclp_async.c
@@ -26,7 +26,6 @@
static int sclp_async_send_wait(char *message);
static struct ctl_table_header *callhome_sysctl_header;
static DEFINE_SPINLOCK(sclp_async_lock);
-static char nodename[64];
#define SCLP_NORMAL_WRITE 0x00
struct async_evbuf {
@@ -52,9 +51,10 @@
static int call_home_on_panic(struct notifier_block *self,
unsigned long event, void *data)
{
- strncat(data, nodename, strlen(nodename));
- sclp_async_send_wait(data);
- return NOTIFY_DONE;
+ strncat(data, init_utsname()->nodename,
+ sizeof(init_utsname()->nodename));
+ sclp_async_send_wait(data);
+ return NOTIFY_DONE;
}
static struct notifier_block call_home_panic_nb = {
@@ -183,10 +183,8 @@
goto out_mem;
rc = atomic_notifier_chain_register(&panic_notifier_list,
&call_home_panic_nb);
- if (rc)
- goto out_mem;
- strncpy(nodename, init_utsname()->nodename, 64);
- goto out;
+ if (!rc)
+ goto out;
out_mem:
kfree(request);
free_page((unsigned long) sccb);