From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk1-f180.google.com (mail-qk1-f180.google.com [209.85.222.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D406B317144 for ; Fri, 15 May 2026 14:26:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.180 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778855190; cv=none; b=qmAJvhk0sK446L/1UaYSSuOPQzpvPzRo2xIdqe+bO/bKB7vNmj6YK4+reJd4+Q+wVJTcZXpv35EdIPksdI2UoFX7q4ICbugwaNgOqSuGmsjyTJCn0enyjyLAlffbJhuSOUv+CXRCxJl6nNORUYPLpoIOXSzClMfH2eudyOy5a5I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778855190; c=relaxed/simple; bh=VOVg/TTcxbvis97d0X2PIuJPa+g5VbyjJLt+s8JUxbY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=splzBKOcjueg3e81mPvuf4kder9c45Z4AmcFjxcXDlxVL2I80fMWEasb1banWLY2Z8crs07copp+LrMS+8lbwiOU2C+oiCsCoYFl60b3+YHOdCQ5jbzD2hDK+jCzRh4b64xL8OesopisiZn7Z6v55oIABx2kTbpN+w9eui7w8kg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=IrR3BwkJ; arc=none smtp.client-ip=209.85.222.180 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="IrR3BwkJ" Received: by mail-qk1-f180.google.com with SMTP id af79cd13be357-90eb7a63a30so285714485a.2 for ; Fri, 15 May 2026 07:26:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1778855188; x=1779459988; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=Fbh4cgdubzbkagDA05ojWdi0ovR3y6wVbfyyv65VFcw=; b=IrR3BwkJ5co7Gy/uTC3NOaHHltRxTCz+FP07uYwngPSZHkSEIQ8zwkQu+Hb6IebXWk DBjGGjtFRf3m6DMn1+rPRdC58D6MbZMNRVUjU7vCRtCHmmhxOlpsqmIqQkkU5UL7eDW1 Zc7g5vPCZ7uCFrEuOyWA5d05vrxEjeaOpjzd/OdYjkbZMWjg/V+CzpLELrYBbkd4RevT 3LInfeml9CByU8EP+rY0YvZ450uENEfhN0fAB2hVJTbDi/m31eUPWoVUe8tRgHpAEiBR D9WQ++Drsyv7QD319HpJZJ9aIEHS33BkUtzd7lxLXcPPl+Vhpbt9gEk6H0zTRamc2tGY o61Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1778855188; x=1779459988; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=Fbh4cgdubzbkagDA05ojWdi0ovR3y6wVbfyyv65VFcw=; b=d/6yKvvF0sr62Qui8aTon50FUiPxdliQlCwbKLk1RC1os6Pbuh1NR5N97KB6AfrTBl AUzt4NjqCyZw6flqUN5z41TDY3TziVEc+DZ2jR6AxKVLFUZUDRs60R1hChwve6uMFz4c no9a83n9Tasb3/ABRmJtbd/AnfTVilYtTDwSxPo8ZemzjFjnf74t375AYfTmdCtJ4orX /kcmHU7QTOb9vA77vpcRJT099wqbXIJFUjERhr3MaK2i880gpuyZsvfh2GjIfH5qng78 R9jI0NaoB+2BbCHOdVtAD+Z9BIfDw4S2OAUSowN/6XjqbA1LVnuOCbwmeZBmGNMJjOok Q4GA== X-Forwarded-Encrypted: i=1; AFNElJ8bDnM6UG3RHPLgpX4mjiZ/nCB9HUDNfDxh65oz8JCSdsHmceyFjEh7z4v/FATgRuXu2ao5CsfxeZZ4nIk=@vger.kernel.org X-Gm-Message-State: AOJu0YwmJBl/rkuFmiP/mzfAsVwAaLm6aJtMADfaC+6pmoidEGBypEO3 I8NJs5ZKQq5j28ROju/rZdrm8s9G5BtzjMPSa5IBwdhlU/FriUnKWW2x X-Gm-Gg: Acq92OE4TLphBVNFHhglmk70CwBL0cUvw2Wvw8zvhWCKcnRUy32HfnVBUpfBhQzNSVZ UQqowlwwAnVPjFujbNKJUe8KD/9LuMYSgJx/Kt+RmyBen8QkDXP+zcLe5860jzVAyLKJCA6eQUS Wh4UdlwEsljtGA/I9wb/CzYgePuH6fAiJYchEEM77V2fub/Xea8wHLVpge/SfTEANZ2Uz4DBnkd 0qLAoyPa0RVbKaBxgelWolapUhWu4CxKrSRWvsKpvYMdRLJnt4J/lIbuP04inoyrob/qpAbBsHL AWeZFyBuihuc8RcUqZMTtjXpJKnY4woKDoaMku80cysGiWM1lenI/slU5CfKeEvKDGVyEfDUtZF 9OGEWhmwOtdphEpaTuT3SC4XumwLN/E81vs1QBoKq2vq/ynJVD7QgqdjcDErJ/sdq1AZw72OqwO c7/GRUuBBs5pRUge+/xOXmx87CJz0fyyEA9rjDX6TvWz+BUaVggZU= X-Received: by 2002:a05:620a:3708:b0:8cf:d3ca:535c with SMTP id af79cd13be357-911cd469227mr693948085a.4.1778855187568; Fri, 15 May 2026 07:26:27 -0700 (PDT) Received: from i4-gl-tmk5904.ad.psu.edu ([130.203.156.186]) by smtp.gmail.com with ESMTPSA id af79cd13be357-910bcf3732dsm544054385a.33.2026.05.15.07.26.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 15 May 2026 07:26:27 -0700 (PDT) From: Yuho Choi To: Vinicius Costa Gomes , Vinod Koul Cc: Dave Jiang , Frank Li , dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, Yuho Choi Subject: [PATCH v2] dmaengine: idxd: fix deadlock and double free in idxd_cdev_open() Date: Fri, 15 May 2026 10:26:23 -0400 Message-ID: <20260515142623.793549-1-dbgh9129@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The failed_dev_add and failed_dev_name error paths in idxd_cdev_open() drop the file-device reference while still holding wq->wq_lock. If this is the last reference, put_device(fdev) runs idxd_file_dev_release(), which takes wq->wq_lock again and deadlocks. Those error paths also fall through into the later ctx cleanup labels after idxd_file_dev_release() has already freed ctx. This can make idxd_xa_pasid_remove(ctx) operate on freed memory and can later free ctx again at the failed label. Use scoped put_device() cleanup for fdev and return from the fdev setup failure path after unlocking wq->wq_lock. Take the WQ reference before fdev can be released so idxd_file_dev_release() always balances a matching idxd_wq_get(). Fixes: e6fd6d7e5f0fe ("dmaengine: idxd: add a device to represent the file opened") Signed-off-by: Yuho Choi --- Changes in v2: - Use __free(put_device) for the file-device reference. - Take the WQ reference before fdev can be released so the release callback's idxd_wq_put() has a matching idxd_wq_get(). drivers/dma/idxd/cdev.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/dma/idxd/cdev.c b/drivers/dma/idxd/cdev.c index 0366c7cf3502..18ff29118d12 100644 --- a/drivers/dma/idxd/cdev.c +++ b/drivers/dma/idxd/cdev.c @@ -216,7 +216,7 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp) struct idxd_user_context *ctx; struct idxd_device *idxd; struct idxd_wq *wq; - struct device *dev, *fdev; + struct device *dev, *fdev __free(put_device) = NULL; int rc = 0; struct iommu_sva *sva = NULL; unsigned int pasid; @@ -289,6 +289,7 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp) fdev->bus = &dsa_bus_type; fdev->type = &idxd_cdev_file_type; + idxd_wq_get(wq); rc = dev_set_name(fdev, "file%d", ctx->id); if (rc < 0) { dev_warn(dev, "set name failure\n"); @@ -301,13 +302,14 @@ static int idxd_cdev_open(struct inode *inode, struct file *filp) goto failed_dev_add; } - idxd_wq_get(wq); + fdev = NULL; mutex_unlock(&wq->wq_lock); return 0; failed_dev_add: failed_dev_name: - put_device(fdev); + mutex_unlock(&wq->wq_lock); + return rc; failed_ida: failed_set_pasid: if (device_user_pasid_enabled(idxd)) -- 2.43.0