On Fri, 30 Aug 2019 12:18:07 +0530 Sachin Sant wrote:
>
> [ 8074.351033] BUG: Kernel NULL pointer dereference at 0x00000038
> [ 8074.351046] Faulting instruction address: 0xc0000000004ddf30
> [ 8074.351052] Oops: Kernel access of bad area, sig: 11 [#1]
> [ 8074.351056] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
Add rcu gp.
--- a/security/keys/request_key_auth.c
+++ b/security/keys/request_key_auth.c
@@ -64,12 +64,19 @@ static int request_key_auth_instantiate(
static void request_key_auth_describe(const struct key *key,
struct seq_file *m)
{
- struct request_key_auth *rka = dereference_key_rcu(key);
+ struct request_key_auth *rka;
+
+ rcu_read_lock();
+ rka = dereference_key_rcu(key);
+ if (!rka)
+ goto out;
seq_puts(m, "key:");
seq_puts(m, key->description);
if (key_is_positive(key))
seq_printf(m, " pid:%d ci:%zu", rka->pid, rka->callout_len);
+out:
+ rcu_read_unlock();
}
/*
