From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794358379; b=i7fTYOO1nwQoseDvOcxyh12FmjiikCI3SD9y41HajqZFOAOvqUKLdpWOtXxuqF2L6kCA 49AueS45HIcANa9jmQNwpi9/JkoMVO3qYzmXdI60FpsZdENWvM8Ip0Mj6QXu7VuweJK2C jdKNuyD9srEQbphRNs8RpeS5y1de2f1np9+9mUwp1zteU2GwKfb331fTcXRD7LobXiYt5 3b6UNmc/2hUQ8XeePdXVntz1UqKrkTqKijIRWAjRra6w1djFvLlS8olvq2bbD8xFtcLKL yJDwYswClsYy5bTufCdB9kuwPgPSWFJZtb3Rn0aj1Pp/Yt25hIQgYnQ4Q3lAiIDk7AA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794358379; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=cSR/TBey1iclnNGalSJzQTp/6lAl0LrfHGJZWIj5asA=; b=qIOY6A58/K0tz2gfNevqjlrECtNn1lpoAEXUM0w2+cxjAdMQa8wCgbjm9zuOrm7G5Zxl P9BksFiTvuLdizLr8oHcnSck3COFbD28xKh+osEqDnqfRBljcU5nlbEOz23e8yYDMwT8u 5W/Potw8flSb684EvhhLM6iHXAIGmF7A/LQHEn1LFHvZa40eUU/Gg2luS9eh5+FZb9s/X 6Kf6vsyq2gq1xcM3G4rBTIBBM2pnlX1JpJ06+VOTEVaz0Vye2Y6vHFrYXOcmAp5tgK8a6 kpVVU0yf/Y8h1ddBYwfrFuBBIvRGkzVcjoUpQJbDit3H30wz9M/lgBe+4h4yd3RHTZQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=R6vhzjrt; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D57B5606A333 for ; Wed, 11 Nov 2026 00:52:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=R6vhzjrt Received: by smtp.kernel.org (Postfix) with ESMTPSA id E925D1F0093D; Wed, 11 Nov 2026 00:52:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794358379; bh=cSR/TBey1iclnNGalSJzQTp/6lAl0LrfHGJZWIj5asA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=R6vhzjrtsqQEHt31xEijSkx2ZZSg7ThsEzWDaa9E7S8M85q6J+EjpocQlMN8DAglm aPhB08HNMkvo6/vuMAx2yLHFaCkFiU2XXm7cWXmomNmgnsm/nWXQDyrLcaRP9B5VGi ZGQu5m+oBGI1NzMloK4zFCHc9J0GyIChPGaY185ehLf/t5FckEE4h/gyjy51kaHF0V O4TLXAVjT0IZpfxDQMuwDUugsyUUmumpuMBvhLANqGDiCiNzSTddLiKQmw4LME5XO1 +RspYaMqX1rghfNhNauFoBbEfILJw4oWAr+bCzwkV17ZYXef2C4TSG5h+Zt0afh0f3 EWOlZzgmM4qcA== From: Sasha Levin To: stable@vger.kernel.org Cc: Wentao Liang , Juergen Gross , Sasha Levin Subject: [PATCH 5.10.y] xen/gntdev: Fix gntdev_dmabuf ref leak in dmabuf_exp_wait_released() Date: Tue, 10 Nov 2026 19:52:57 -0500 Message-ID: <20261111005027.324382-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261107062016-failed-5.10-6f165abe2b40@kernel.org> References: <20261107062016-failed-5.10-6f165abe2b40@kernel.org> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Wentao Liang [ Upstream commit 6f165abe2b40ede71c98956cd74cd17c18505e75 ] dmabuf_exp_wait_released() takes a reference on the exported gntdev_dmabuf with dmabuf_exp_wait_obj_get_dmabuf() and passes it to dmabuf_exp_wait_obj_new(), which drops that reference after adding the wait object to the wait list. When the wait object allocation fails, dmabuf_exp_wait_obj_new() returns ERR_PTR(-ENOMEM) early and the reference is never dropped, leaking a reference to the exported gntdev_dmabuf. Drop the reference on the allocation failure path so the reference is consumed whether the wait object is created or not. Fixes: 932d6562179e ("xen/gntdev: Add initial support for dma-buf UAPI") Cc: stable@vger.kernel.org Signed-off-by: Wentao Liang Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross Message-ID: <20260916170956.2086505-1-vulab@iscas.ac.cn> [ sashal: adjusted allocation context for kzalloc(sizeof(*obj), GFP_KERNEL) instead of kzalloc_obj(*obj) ] Signed-off-by: Sasha Levin --- drivers/xen/gntdev-dmabuf.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/xen/gntdev-dmabuf.c b/drivers/xen/gntdev-dmabuf.c index 398ea69c176c1..8ed7aba6a6734 100644 --- a/drivers/xen/gntdev-dmabuf.c +++ b/drivers/xen/gntdev-dmabuf.c @@ -102,8 +102,10 @@ dmabuf_exp_wait_obj_new(struct gntdev_dmabuf_priv *priv, struct gntdev_dmabuf_wait_obj *obj; obj = kzalloc(sizeof(*obj), GFP_KERNEL); - if (!obj) + if (!obj) { + kref_put(&gntdev_dmabuf->u.exp.refcount, dmabuf_exp_release); return ERR_PTR(-ENOMEM); + } init_completion(&obj->completion); obj->gntdev_dmabuf = gntdev_dmabuf; -- 2.53.0