From: David Howells <dhowells@redhat.com>
To: Hillf Danton <hdanton@sina.com>
Cc: dhowells@redhat.com, Sachin Sant <sachinp@linux.vnet.ibm.com>,
keyrings@vger.kernel.org, linux-kernel@vger.kernel.org,
linuxppc-dev@ozlabs.org
Subject: Re: Oops (request_key_auth_describe) while running cve-2016-7042 from LTP
Date: Fri, 30 Aug 2019 15:13:03 +0100 [thread overview]
Message-ID: <4384.1567174383@warthog.procyon.org.uk> (raw)
In-Reply-To: <20190830085646.14740-1-hdanton@sina.com>
Hillf Danton <hdanton@sina.com> wrote:
> - struct request_key_auth *rka = dereference_key_rcu(key);
> + struct request_key_auth *rka;
> +
> + rcu_read_lock();
> + rka = dereference_key_rcu(key);
This shouldn't help as the caller, proc_keys_show(), is holding the RCU read
lock across the call. The end of the function reads:
if (key->type->describe)
key->type->describe(key, m);
seq_putc(m, '\n');
rcu_read_unlock();
return 0;
}
and the documentation says "This method will be called with the RCU read lock
held".
I suspect the actual bugfix is this bit:
> + if (!rka)
> + goto out;
David
next prev parent reply other threads:[~2019-08-30 14:18 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190830145454.B91DF125411@zmta02.collab.prod.int.phx2.redhat.com>
2019-08-30 8:56 ` Oops (request_key_auth_describe) while running cve-2016-7042 from LTP Hillf Danton
2019-08-30 10:32 ` Sachin Sant
2019-08-30 14:13 ` David Howells [this message]
2019-08-30 14:54 ` Hillf Danton
2019-08-30 15:12 ` David Howells
2019-08-31 1:20 ` Hillf Danton
2019-08-30 6:48 Sachin Sant
2019-08-30 15:13 ` David Howells
2019-08-31 4:57 ` Sachin Sant
2019-09-02 7:14 ` David Howells
2019-09-02 11:40 ` Hillf Danton
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