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 1C939146909; Tue, 27 Feb 2024 13:47:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709041663; cv=none; b=K9SpcygM0VOyehTwt5Rjts5YIOmLBUwGCoCIYRVeO2uWcbFZrJJYbqsgM+ELn19nYkbE74Cmjp3tvyq9QecAW4XSoRcIoJ1sAd22I6FDMfa8GoZ6fcLKJnc4da1VVcVtKMb8mi3gop9YNYzbUjY+KPubJ+x3KdSq/qGclQU2/NI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709041663; c=relaxed/simple; bh=gcuk+iOJvgr2Sx6vCVYq8DvXeOpaPNlWDvIMCo6XzcE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hNyy8rzNkfcCqZhRVC6xLIEzfSIra3owz0+3qCtGjQ1lQOR0Kf4dwuiBG0IDTG7AhrMth7LKEuU2+cN5nDca8XeKrb1B85YuviYgHCG2p3P4otk1a2N9s3L6kl59qdyFUD8+vnWjRjw0+DRevBRu3FKWn58Y1GtoXvQo28mw0ko= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=0C7WB224; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="0C7WB224" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9DA47C433C7; Tue, 27 Feb 2024 13:47:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1709041663; bh=gcuk+iOJvgr2Sx6vCVYq8DvXeOpaPNlWDvIMCo6XzcE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0C7WB224HjVrsU8pu2KIRCfGsVDS61BzDPOGQQwuGluwfGUqNqAOnl8n9qShryHhJ rb0wzJsJ7ascQ3BVN2GxAs0ADMWpd77iH1+ZLn0EPalso6B0un70X9JI8N2LjsOEMk +h8MrPradhDUObzGvTOZi1zClQ1rI5M907Sbhpos= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Maksim Kiselev , Christoph Hellwig , Jens Axboe , Sasha Levin Subject: [PATCH 6.6 027/299] aoe: avoid potential deadlock at set_capacity Date: Tue, 27 Feb 2024 14:22:18 +0100 Message-ID: <20240227131626.697400965@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240227131625.847743063@linuxfoundation.org> References: <20240227131625.847743063@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Maksim Kiselev [ Upstream commit e169bd4fb2b36c4b2bee63c35c740c85daeb2e86 ] Move set_capacity() outside of the section procected by (&d->lock). To avoid possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- [1] lock(&bdev->bd_size_lock); local_irq_disable(); [2] lock(&d->lock); [3] lock(&bdev->bd_size_lock); [4] lock(&d->lock); *** DEADLOCK *** Where [1](&bdev->bd_size_lock) hold by zram_add()->set_capacity(). [2]lock(&d->lock) hold by aoeblk_gdalloc(). And aoeblk_gdalloc() is trying to acquire [3](&bdev->bd_size_lock) at set_capacity() call. In this situation an attempt to acquire [4]lock(&d->lock) from aoecmd_cfg_rsp() will lead to deadlock. So the simplest solution is breaking lock dependency [2](&d->lock) -> [3](&bdev->bd_size_lock) by moving set_capacity() outside. Signed-off-by: Maksim Kiselev Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20240124072436.3745720-2-bigunclemax@gmail.com Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- drivers/block/aoe/aoeblk.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/block/aoe/aoeblk.c b/drivers/block/aoe/aoeblk.c index cf6883756155a..37eff1c974515 100644 --- a/drivers/block/aoe/aoeblk.c +++ b/drivers/block/aoe/aoeblk.c @@ -333,6 +333,7 @@ aoeblk_gdalloc(void *vp) struct gendisk *gd; mempool_t *mp; struct blk_mq_tag_set *set; + sector_t ssize; ulong flags; int late = 0; int err; @@ -395,7 +396,7 @@ aoeblk_gdalloc(void *vp) gd->minors = AOE_PARTITIONS; gd->fops = &aoe_bdops; gd->private_data = d; - set_capacity(gd, d->ssize); + ssize = d->ssize; snprintf(gd->disk_name, sizeof gd->disk_name, "etherd/e%ld.%d", d->aoemajor, d->aoeminor); @@ -404,6 +405,8 @@ aoeblk_gdalloc(void *vp) spin_unlock_irqrestore(&d->lock, flags); + set_capacity(gd, ssize); + err = device_add_disk(NULL, gd, aoe_attr_groups); if (err) goto out_disk_cleanup; -- 2.43.0