All of lore.kernel.org
 help / color / mirror / Atom feed
From: Yu Kuai <yukuai1@huaweicloud.com>
To: paolo.valente@linaro.org, axboe@kernel.dk, jack@suse.cz
Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org,
	yukuai3@huawei.com, yukuai1@huaweicloud.com, yi.zhang@huawei.com
Subject: [PATCH] block, bfq: fix uaf for bfqq in bfq_exit_icq_bfqq
Date: Mon, 26 Dec 2022 11:06:05 +0800	[thread overview]
Message-ID: <20221226030605.1437081-1-yukuai1@huaweicloud.com> (raw)

From: Yu Kuai <yukuai3@huawei.com>

Commit 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'")
will access 'bic->bfqq' in bic_set_bfqq(), however, bfq_exit_icq_bfqq()
can free bfqq first, and then call bic_set_bfqq(), which will cause uaf.

Fix the problem by moving bfq_exit_bfqq() behind bic_set_bfqq().

Fixes: 64dc8c732f5c ("block, bfq: fix possible uaf for 'bfqq->bic'")
Reported-by: Yi Zhang <yi.zhang@redhat.com>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
---
 block/bfq-iosched.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c
index 16f43bbc575a..ccf2204477a5 100644
--- a/block/bfq-iosched.c
+++ b/block/bfq-iosched.c
@@ -5317,8 +5317,8 @@ static void bfq_exit_icq_bfqq(struct bfq_io_cq *bic, bool is_sync)
 		unsigned long flags;
 
 		spin_lock_irqsave(&bfqd->lock, flags);
-		bfq_exit_bfqq(bfqd, bfqq);
 		bic_set_bfqq(bic, NULL, is_sync);
+		bfq_exit_bfqq(bfqd, bfqq);
 		spin_unlock_irqrestore(&bfqd->lock, flags);
 	}
 }
-- 
2.31.1


             reply	other threads:[~2022-12-26  2:45 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-12-26  3:06 Yu Kuai [this message]
2022-12-26 11:18 ` [PATCH] block, bfq: fix uaf for bfqq in bfq_exit_icq_bfqq Jan Kara
2022-12-26 19:11 ` Jens Axboe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20221226030605.1437081-1-yukuai1@huaweicloud.com \
    --to=yukuai1@huaweicloud.com \
    --cc=axboe@kernel.dk \
    --cc=jack@suse.cz \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=paolo.valente@linaro.org \
    --cc=yi.zhang@huawei.com \
    --cc=yukuai3@huawei.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.