From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 65FDB1170E for ; Mon, 11 Sep 2023 14:07:51 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DAAE1C433CB; Mon, 11 Sep 2023 14:07:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1694441271; bh=e4nYY/j5VtaYznp+g1N0zPH+EB+nkKcBbqV/8iRoZJA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oLydnQiCG6hRssPWWMdhCGDAOAdrP7Shm8q0pidIbRKrm5vB8CaoKCUt/7Q7308VP Qucfg1pGXxrUeuaCiYBjIc6DcBW7m2lgqyx3ffP9k+61wYm66A4Ses3U7ttufJEzw9 cvM02PryDVz/YTNaeE0Dsctwb5B9maBfNxXt8drk= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yu Kuai , Christoph Hellwig , Song Liu , Sasha Levin , Corey Hickey Subject: [PATCH 6.5 355/739] md/raid5-cache: fix null-ptr-deref for r5l_flush_stripe_to_raid() Date: Mon, 11 Sep 2023 15:42:34 +0200 Message-ID: <20230911134701.048708684@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230911134650.921299741@linuxfoundation.org> References: <20230911134650.921299741@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yu Kuai [ Upstream commit 0d0bd28c500173bfca78aa840f8f36d261ef1765 ] r5l_flush_stripe_to_raid() will check if the list 'flushing_ios' is empty, and then submit 'flush_bio', however, r5l_log_flush_endio() is clearing the list first and then clear the bio, which will cause null-ptr-deref: T1: submit flush io raid5d handle_active_stripes r5l_flush_stripe_to_raid // list is empty // add 'io_end_ios' to the list bio_init submit_bio // io1 T2: io1 is done r5l_log_flush_endio list_splice_tail_init // clear the list T3: submit new flush io ... r5l_flush_stripe_to_raid // list is empty // add 'io_end_ios' to the list bio_init bio_uninit // clear bio->bi_blkg submit_bio // null-ptr-deref Fix this problem by clearing bio before clearing the list in r5l_log_flush_endio(). Fixes: 0dd00cba99c3 ("raid5-cache: fully initialize flush_bio when needed") Reported-and-tested-by: Corey Hickey Closes: https://lore.kernel.org/all/cddd7213-3dfd-4ab7-a3ac-edd54d74a626@fatooh.org/ Signed-off-by: Yu Kuai Reviewed-by: Christoph Hellwig Signed-off-by: Song Liu Signed-off-by: Sasha Levin --- drivers/md/raid5-cache.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index 2eac4a50d99bd..8b3fc484fd758 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -1260,14 +1260,13 @@ static void r5l_log_flush_endio(struct bio *bio) if (bio->bi_status) md_error(log->rdev->mddev, log->rdev); + bio_uninit(bio); spin_lock_irqsave(&log->io_list_lock, flags); list_for_each_entry(io, &log->flushing_ios, log_sibling) r5l_io_run_stripes(io); list_splice_tail_init(&log->flushing_ios, &log->finished_ios); spin_unlock_irqrestore(&log->io_list_lock, flags); - - bio_uninit(bio); } /* -- 2.40.1