linux-kernel - [PATCH 4.9 049/177] blk-mq: Fix tagset reinit in the presence of cpu hot-unplug

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20171218152912.457967632@linuxfoundation.org>
Date:   Mon, 18 Dec 2017 16:47:52 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Yi Zhang <yizhan@...hat.com>,
        Sagi Grimberg <sagi@...mberg.me>, Jens Axboe <axboe@...com>,
        Sasha Levin <alexander.levin@...izon.com>
Subject: [PATCH 4.9 049/177] blk-mq: Fix tagset reinit in the presence of cpu hot-unplug

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Sagi Grimberg <sagi@...mberg.me>


[ Upstream commit 0067d4b020ea07a58540acb2c5fcd3364bf326e0 ]

In case cpu was unplugged, we need to make sure not to assume
that the tags for that cpu are still allocated. so check
for null tags when reinitializing a tagset.

Reported-by: Yi Zhang <yizhan@...hat.com>
Signed-off-by: Sagi Grimberg <sagi@...mberg.me>
Signed-off-by: Jens Axboe <axboe@...com>
Signed-off-by: Sasha Levin <alexander.levin@...izon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
---
 block/blk-mq-tag.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -311,6 +311,9 @@ int blk_mq_reinit_tagset(struct blk_mq_t
 	for (i = 0; i < set->nr_hw_queues; i++) {
 		struct blk_mq_tags *tags = set->tags[i];
 
+		if (!tags)
+			continue;
+
 		for (j = 0; j < tags->nr_tags; j++) {
 			if (!tags->rqs[j])
 				continue;