From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZrJRJsGVAsXtcI6j52YCajgFGr5kHEB2RvwK8bCn6LNmxjC/x3S6CXgzjnwjydrhYaDL3D+ ARC-Seal: i=1; a=rsa-sha256; t=1525116490; cv=none; d=google.com; s=arc-20160816; b=wUcr+y/71CKXvCj+EyuD4GHjh0UMDyY2DiqRJ13T7UHxHIs0sSSIv7XhRPiroatFWk BUSgFhah/LLQSpl8371GGvAHjA2vW1ciYW/vT2XcYEUMDbKPRPebwuN/V5nBN6+T3iDE fOWbVGc36OsOQDH5u9ySpaVLFs+uEeGdDzR410hJFAh+lAq9/A2OshUKGLWyOA3jDgpq Lp8yvzrEnnIWE4fgSDye35ue3EvtDuMSlfxHFV4I/Fh+Qj16mHqiDDj0nLUUf49njmoU pZ39Ww4YeQlVCEqH2eoh8HHvnR4cORg0mYp5GzP14dg+u7+hZGs3MzygVl6Ju1OJIAlA SATg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:dmarc-filter:arc-authentication-results; bh=pC7AIVFl1dYCQOFvkOidnzo7QLpcr5CtVjy/WpOfohw=; b=lyFil/hDfXwphsTyQEgyVtyQCmWwyhkchm9J+aUeWkS1UzYB0fbz+/oLsoK1CAU4o1 2/eEeVaJdB7yaRX9l+3/rY8iwPm8BpiJA31ihdeviZB55eGOEU0MeX2+zYpeJwiuvPIn ak5KeBzZuguMXTk8c2ZOrp0Hi9di1wCB4oomOJlp1PnxBSCYG/YwSsIBMoiSqmdaO43h 20worK1u1J/JSQ2vrI3edme0SLfXR0MKt9siiROjltdkFqiYWPFttW4xlQEsoLYtF6Pn ACQfMSoaPRUQ0lqIyD4cGUGz2eaGx1dsob/WS6RT06EhP8SKIa5oqM1frvxqza1sDtJC aNUw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of srs0=k66p=ht=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=K66P=HT=linuxfoundation.org=gregkh@kernel.org Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of srs0=k66p=ht=linuxfoundation.org=gregkh@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=K66P=HT=linuxfoundation.org=gregkh@kernel.org DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6622A22E02 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=fail smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jann Horn , Theodore Tso Subject: [PATCH 4.16 006/113] random: set up the NUMA crng instances after the CRNG is fully initialized Date: Mon, 30 Apr 2018 12:23:37 -0700 Message-Id: <20180430184015.339138140@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180430184015.043892819@linuxfoundation.org> References: <20180430184015.043892819@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1599200549530804380?= X-GMAIL-MSGID: =?utf-8?q?1599200549530804380?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Theodore Ts'o commit 8ef35c866f8862df074a49a93b0309725812dea8 upstream. Until the primary_crng is fully initialized, don't initialize the NUMA crng nodes. Otherwise users of /dev/urandom on NUMA systems before the CRNG is fully initialized can get very bad quality randomness. Of course everyone should move to getrandom(2) where this won't be an issue, but there's a lot of legacy code out there. This related to CVE-2018-1108. Reported-by: Jann Horn Fixes: 1e7f583af67b ("random: make /dev/urandom scalable for silly...") Cc: stable@kernel.org # 4.8+ Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman --- drivers/char/random.c | 46 +++++++++++++++++++++++++++------------------- 1 file changed, 27 insertions(+), 19 deletions(-) --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -787,6 +787,32 @@ static void crng_initialize(struct crng_ crng->init_time = jiffies - CRNG_RESEED_INTERVAL - 1; } +#ifdef CONFIG_NUMA +static void numa_crng_init(void) +{ + int i; + struct crng_state *crng; + struct crng_state **pool; + + pool = kcalloc(nr_node_ids, sizeof(*pool), GFP_KERNEL|__GFP_NOFAIL); + for_each_online_node(i) { + crng = kmalloc_node(sizeof(struct crng_state), + GFP_KERNEL | __GFP_NOFAIL, i); + spin_lock_init(&crng->lock); + crng_initialize(crng); + pool[i] = crng; + } + mb(); + if (cmpxchg(&crng_node_pool, NULL, pool)) { + for_each_node(i) + kfree(pool[i]); + kfree(pool); + } +} +#else +static void numa_crng_init(void) {} +#endif + /* * crng_fast_load() can be called by code in the interrupt service * path. So we can't afford to dilly-dally. @@ -893,6 +919,7 @@ static void crng_reseed(struct crng_stat spin_unlock_irqrestore(&crng->lock, flags); if (crng == &primary_crng && crng_init < 2) { invalidate_batched_entropy(); + numa_crng_init(); crng_init = 2; process_random_ready_list(); wake_up_interruptible(&crng_init_wait); @@ -1731,29 +1758,10 @@ static void init_std_data(struct entropy */ static int rand_initialize(void) { -#ifdef CONFIG_NUMA - int i; - struct crng_state *crng; - struct crng_state **pool; -#endif - init_std_data(&input_pool); init_std_data(&blocking_pool); crng_initialize(&primary_crng); crng_global_init_time = jiffies; - -#ifdef CONFIG_NUMA - pool = kcalloc(nr_node_ids, sizeof(*pool), GFP_KERNEL|__GFP_NOFAIL); - for_each_online_node(i) { - crng = kmalloc_node(sizeof(struct crng_state), - GFP_KERNEL | __GFP_NOFAIL, i); - spin_lock_init(&crng->lock); - crng_initialize(crng); - pool[i] = crng; - } - mb(); - crng_node_pool = pool; -#endif return 0; } early_initcall(rand_initialize);