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 205541607B7; Mon, 24 Feb 2025 14:57:21 +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=1740409041; cv=none; b=V7JQO8qIjp7N/Ge8aDOUp6Df/WoVn0hOQSKg2c5kASJsCamFH3QRBzQLTaJAR6j1Lo4ozx1PpsK1P53WIw/HqQtieCNsb59iGbpuPO/9fMXskOXR+LGhJuwiR2znPUG+eFZ8qm4/bx0YWZfva4Wxbx+YMVGWDz267qV4MiSBdRY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740409041; c=relaxed/simple; bh=viy6Q5NKzorMjdjmJBfzFtwaUsnhniUrp0ti8ybuPmE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fgerq1hj5nsXvBOrszQolNVFOIrzS+yYVCvN1xuleQHAnAEBDn1nXBXSlg2r/d9wrRMboxaTMVens0+9TVjnQapcMDZTwSgAUe8W0neukslx19grTX/foTKiKmy0pOo2Tmu9mSSst0ERsAeFSV2AIWbLnR4sjZUgLyYgX0BD3Tk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=sg+QDEvT; 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="sg+QDEvT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 83E6FC4CED6; Mon, 24 Feb 2025 14:57:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1740409041; bh=viy6Q5NKzorMjdjmJBfzFtwaUsnhniUrp0ti8ybuPmE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sg+QDEvT4oVBfr5oRoGMDW7PeEA5TeGWdrXczra/OeX+2ePMW42ydDLEDMxcdcdcf arbUTmtaJmOfk7ONJTzxy0H3EIoSv0YLn7l16RDM+MdyeHGu/mADkRu3ltUlCK62bx oGzPQZXcbC2130meHrJo+85oBk9TGq8DVJ+NGYEM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Hannes Reinecke , Nilay Shroff , Sagi Grimberg , Christoph Hellwig , Chaitanya Kulkarni , Shinichiro Kawasaki , Keith Busch , Sasha Levin Subject: [PATCH 6.13 079/138] nvmet: Fix crash when a namespace is disabled Date: Mon, 24 Feb 2025 15:35:09 +0100 Message-ID: <20250224142607.584895232@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250224142604.442289573@linuxfoundation.org> References: <20250224142604.442289573@linuxfoundation.org> User-Agent: quilt/0.68 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 6.13-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hannes Reinecke [ Upstream commit 4082326807072b71496501b6a0c55ffe8d5092a5 ] The namespace percpu counter protects pending I/O, and we can only safely diable the namespace once the counter drop to zero. Otherwise we end up with a crash when running blktests/nvme/058 (eg for loop transport): [ 2352.930426] [ T53909] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN PTI [ 2352.930431] [ T53909] KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] [ 2352.930434] [ T53909] CPU: 3 UID: 0 PID: 53909 Comm: kworker/u16:5 Tainted: G W 6.13.0-rc6 #232 [ 2352.930438] [ T53909] Tainted: [W]=WARN [ 2352.930440] [ T53909] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014 [ 2352.930443] [ T53909] Workqueue: nvmet-wq nvme_loop_execute_work [nvme_loop] [ 2352.930449] [ T53909] RIP: 0010:blkcg_set_ioprio+0x44/0x180 as the queue is already torn down when calling submit_bio(); So we need to init the percpu counter in nvmet_ns_enable(), and wait for it to drop to zero in nvmet_ns_disable() to avoid having I/O pending after the namespace has been disabled. Fixes: 74d16965d7ac ("nvmet-loop: avoid using mutex in IO hotpath") Signed-off-by: Hannes Reinecke Reviewed-by: Nilay Shroff Reviewed-by: Sagi Grimberg Reviewed-by: Christoph Hellwig Reviewed-by: Chaitanya Kulkarni Tested-by: Shin'ichiro Kawasaki Signed-off-by: Keith Busch Signed-off-by: Sasha Levin --- drivers/nvme/target/core.c | 40 ++++++++++++++++++-------------------- 1 file changed, 19 insertions(+), 21 deletions(-) diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c index fde6c555af619..56e3c870ab4c3 100644 --- a/drivers/nvme/target/core.c +++ b/drivers/nvme/target/core.c @@ -606,6 +606,9 @@ int nvmet_ns_enable(struct nvmet_ns *ns) goto out_dev_put; } + if (percpu_ref_init(&ns->ref, nvmet_destroy_namespace, 0, GFP_KERNEL)) + goto out_pr_exit; + nvmet_ns_changed(subsys, ns->nsid); ns->enabled = true; xa_set_mark(&subsys->namespaces, ns->nsid, NVMET_NS_ENABLED); @@ -613,6 +616,9 @@ int nvmet_ns_enable(struct nvmet_ns *ns) out_unlock: mutex_unlock(&subsys->lock); return ret; +out_pr_exit: + if (ns->pr.enable) + nvmet_pr_exit_ns(ns); out_dev_put: list_for_each_entry(ctrl, &subsys->ctrls, subsys_entry) pci_dev_put(radix_tree_delete(&ctrl->p2p_ns_map, ns->nsid)); @@ -638,6 +644,19 @@ void nvmet_ns_disable(struct nvmet_ns *ns) mutex_unlock(&subsys->lock); + /* + * Now that we removed the namespaces from the lookup list, we + * can kill the per_cpu ref and wait for any remaining references + * to be dropped, as well as a RCU grace period for anyone only + * using the namepace under rcu_read_lock(). Note that we can't + * use call_rcu here as we need to ensure the namespaces have + * been fully destroyed before unloading the module. + */ + percpu_ref_kill(&ns->ref); + synchronize_rcu(); + wait_for_completion(&ns->disable_done); + percpu_ref_exit(&ns->ref); + if (ns->pr.enable) nvmet_pr_exit_ns(ns); @@ -660,22 +679,6 @@ void nvmet_ns_free(struct nvmet_ns *ns) if (ns->nsid == subsys->max_nsid) subsys->max_nsid = nvmet_max_nsid(subsys); - mutex_unlock(&subsys->lock); - - /* - * Now that we removed the namespaces from the lookup list, we - * can kill the per_cpu ref and wait for any remaining references - * to be dropped, as well as a RCU grace period for anyone only - * using the namepace under rcu_read_lock(). Note that we can't - * use call_rcu here as we need to ensure the namespaces have - * been fully destroyed before unloading the module. - */ - percpu_ref_kill(&ns->ref); - synchronize_rcu(); - wait_for_completion(&ns->disable_done); - percpu_ref_exit(&ns->ref); - - mutex_lock(&subsys->lock); subsys->nr_namespaces--; mutex_unlock(&subsys->lock); @@ -705,9 +708,6 @@ struct nvmet_ns *nvmet_ns_alloc(struct nvmet_subsys *subsys, u32 nsid) ns->nsid = nsid; ns->subsys = subsys; - if (percpu_ref_init(&ns->ref, nvmet_destroy_namespace, 0, GFP_KERNEL)) - goto out_free; - if (ns->nsid > subsys->max_nsid) subsys->max_nsid = nsid; @@ -730,8 +730,6 @@ struct nvmet_ns *nvmet_ns_alloc(struct nvmet_subsys *subsys, u32 nsid) return ns; out_exit: subsys->max_nsid = nvmet_max_nsid(subsys); - percpu_ref_exit(&ns->ref); -out_free: kfree(ns); out_unlock: mutex_unlock(&subsys->lock); -- 2.39.5