From nobody Sat Jul 25 03:50:11 2026 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.19]) (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 6E92E291C10; Sun, 19 Jul 2026 10:20:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.19 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784456462; cv=none; b=gyFfMOJoJVg1CIqUwmZ02gQbvldEsKOZQYwcR4WgdrfHUsLrEci8yqqSxeXL5X4/GmHAhFEYgDKGBFTqPf1tGyrTr0QbOh4lIaZNVTmgRzeaYLYNcNiT66ndXMPBqLEEGYj3j1csDGmYlRdaDDYm3OGiMTbin/lxhEn19b8KQNI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784456462; c=relaxed/simple; bh=YWNPSNHXhUMQZugFK/yG01ivnCUCqLg/UiD4aCM9rig=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=LDnhbKnugPVne1f28PLtlBPy5FLa6Nw4UJgQVkXUT/S/931rubax14KF3HUuouWC5Djl5qHirCG6cGIxl35kx8IOTJaCDV/BxMtFk8fR1iQcEhAVt1zxLuP3NPANuAIWm9IMib7yETMtZKg5V5BpcwF17TCLFIfNvMTDVmkpW2Q= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=Y8vwOk14; arc=none smtp.client-ip=192.198.163.19 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="Y8vwOk14" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1784456460; x=1815992460; h=from:date:subject:mime-version:content-transfer-encoding: message-id:to:cc; bh=YWNPSNHXhUMQZugFK/yG01ivnCUCqLg/UiD4aCM9rig=; b=Y8vwOk14n6skjEEe/pBWQjfath/Kez5pm6l77+vj5CdzSlH95Frl5rVM 8/Ip1h8cubUBSoUg6GkWqzIP4ia3uJ02EHISRdKF3IQc+yKRjqf7IiqSN HqESB2m8uA4ZM4fgSjscw5YsDLWTk6NwN30swJVNMCSVmoq3clHfxQUqk vdSYm1jvfyGV/74EHOJG4C5zYdKV0dctZ6W8YQtgzRCpv5S/iRIb22FnP vBxoXwoems7xpIwjuI6FklCiLzPwDx4k1+6XS1KVWJpeeLvjVKTGdXvZk qXSqIN72Myq8T28KjXVc4iNcspEUH/Hg+M/F63o1rDkbd7TXWZSgOcGNG Q==; X-CSE-ConnectionGUID: fec5N1BJTtWDBmHoGO35cw== X-CSE-MsgGUID: iS0+1YJSS36/3RbluoQzqw== X-IronPort-AV: E=McAfee;i="6800,10657,11850"; a="84048444" X-IronPort-AV: E=Sophos;i="6.25,172,1779174000"; d="scan'208";a="84048444" Received: from fmviesa006.fm.intel.com ([10.60.135.146]) by fmvoesa113.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jul 2026 03:20:59 -0700 X-CSE-ConnectionGUID: lwnsNq9wTgKc6rnz4TW7fw== X-CSE-MsgGUID: i1O1v9PqTPygTM4MBmRGRg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,172,1779174000"; d="scan'208";a="252818198" Received: from sannilnx-dsk.jer.intel.com (HELO [127.0.1.1]) ([10.12.231.107]) by fmviesa006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jul 2026 03:20:56 -0700 From: Alexander Usyskin Date: Sun, 19 Jul 2026 12:57:55 +0300 Subject: [PATCH char-misc] mei: pull kvfree out of spinlock Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20260719-kvfree_out_of_spinlock-v1-1-e07d6333bea7@intel.com> X-B4-Tracking: v=1; b=H4sIAAAAAAAC/x3MQQqDMBBA0avIrBswLlL0KqWEOJnoYJvIjEpBv HvTLt/i/xOUhElhaE4QOli55Ap7awDnkCcyHKuhazvX3m1vliMJkS/75kvyunJ+FVxMGtEGjNE F56DGq1Diz3/8+J3EvFkRntf1BbRZiWZzAAAA X-Change-ID: 20260719-kvfree_out_of_spinlock-fbc1acdd6a66 To: Arnd Bergmann , Greg Kroah-Hartman , Tomas Winkler Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Menachem Adin , Alexander Usyskin X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1784455091; l=3228; i=alexander.usyskin@intel.com; s=20260315; h=from:subject:message-id; bh=YWNPSNHXhUMQZugFK/yG01ivnCUCqLg/UiD4aCM9rig=; b=skAZhVLV2E4YBgbVTqlrKFjgeOIpFC6zP1QdOK1nBqDlhJUXDerbKKiO9EKbFXEuuzppSKCIO XtY/D89JFYXAxDUeIfHL0f3Kw+7g1kcX5+XAOzPaSfIPDwl90zMRSA9 X-Developer-Key: i=alexander.usyskin@intel.com; a=ed25519; pk=X+qoF/nFCdDOV04IForWSxnkyoCAbUE10egZi6PSfcU= The read buffer allocation was changed from kmalloc() to kvmalloc(). This buffer is part of mei_cl_cb structure that can be queued in rd_complete queue protected by spinlock. Releasing the structure leads to errors like below when freeing buffer that allocated non-contiguous: BUG: sleeping function called from invalid context at mm/vmalloc.c:3448 Separate mei_cl_cb structure dequeue and release to perform only dequeue under spinlock and push release out of spinlock. Cc: stable@vger.kernel.org Fixes: 4adf613e01bf ("mei: use kvmalloc for read buffer") Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/work_items/16359 Reviewed-by: Menachem Adin Signed-off-by: Alexander Usyskin --- drivers/misc/mei/client.c | 25 +++++++++++++++---------- 1 file changed, 15 insertions(+), 10 deletions(-) diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c index 643b0039cc72..26d2b2742d50 100644 --- a/drivers/misc/mei/client.c +++ b/drivers/misc/mei/client.c @@ -425,18 +425,24 @@ static void mei_io_tx_list_free_cl(struct list_head *= head, } =20 /** - * mei_io_list_free_fp - free cb from a list that matches file pointer + * mei_io_rd_list_free_fp - free cb from a rd_completed list that matches = file pointer * - * @head: io list + * @cl: host client * @fp: file pointer (matching cb file object), may be NULL */ -static void mei_io_list_free_fp(struct list_head *head, const struct file = *fp) +static void mei_io_rd_list_free_fp(struct mei_cl *cl, const struct file *f= p) { struct mei_cl_cb *cb, *next; + LIST_HEAD(cmpl_list); =20 - list_for_each_entry_safe(cb, next, head, list) + spin_lock(&cl->rd_completed_lock); + list_for_each_entry_safe(cb, next, &cl->rd_completed, list) if (!fp || fp =3D=3D cb->fp) - mei_io_cb_free(cb); + list_move(&cb->list, &cmpl_list); + spin_unlock(&cl->rd_completed_lock); + + list_for_each_entry_safe(cb, next, &cmpl_list, list) + mei_io_cb_free(cb); } =20 /** @@ -565,9 +571,7 @@ int mei_cl_flush_queues(struct mei_cl *cl, const struct= file *fp) mei_io_list_flush_cl(&cl->dev->ctrl_rd_list, cl); mei_cl_free_pending(cl); } - spin_lock(&cl->rd_completed_lock); - mei_io_list_free_fp(&cl->rd_completed, fp); - spin_unlock(&cl->rd_completed_lock); + mei_io_rd_list_free_fp(cl, fp); =20 return 0; } @@ -1401,7 +1405,7 @@ void mei_cl_add_rd_completed(struct mei_cl *cl, struc= t mei_cl_cb *cb) } =20 /** - * mei_cl_del_rd_completed - free read completed callback with lock + * mei_cl_del_rd_completed - unlink read completed callback with lock and = free it * * @cl: host client * @cb: callback block @@ -1410,8 +1414,9 @@ void mei_cl_add_rd_completed(struct mei_cl *cl, struc= t mei_cl_cb *cb) void mei_cl_del_rd_completed(struct mei_cl *cl, struct mei_cl_cb *cb) { spin_lock(&cl->rd_completed_lock); - mei_io_cb_free(cb); + list_del_init(&cb->list); spin_unlock(&cl->rd_completed_lock); + mei_io_cb_free(cb); } =20 /** --- base-commit: 775553d19b163446c38c5ff24dd0a01065376932 change-id: 20260719-kvfree_out_of_spinlock-fbc1acdd6a66 Best regards, --=20 Alexander Usyskin