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=1794357862; b=PTBs6jLVBeGu1xLrq5am4GqZ8dyH1YzW7YJnvVQEiSx149rUg4W6CS7NKQ+w/Yiv0+Bx 8bTZEHk5srJsMZJE4JKZmyX+VvOZMDrpkj+WAlgiEBSEHD6+VGhI3nLwnWdX1kF8tYlLJ D7isIi2pMUyXjf4DDpfu/U5+ObMxCfbY/vLCv9+yNQorVhJtQd3brv+63zlldvW/Tov/W l5Ph217nXuEe/pNSt7fOuMiX3NMJsFLpIiz23oWm0CdkTwMHxtgPp4X4oz1cNtnn7oJ2M fUvBicUbIY8+ANlukC+D7NOkfnWExezprx+hejz0JufwUKZk9kNS/zpZAPCbLpc/OKQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794357862; 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=l8Roj2VPy6+Mtw/GZebOzjCERNOM0Dfks8B2Udf3MyFP+JzlyM9Elb0OO1gC56y258Cx bB1kEf1waaHtZoxL+jNhM9A1pTGrdWiOc32pDopd7/O6LRPuUohcy66hQ7GzysRUnS1NU 49YBhRtmY6ElDiu28CZDPtfm+Ybt7yVkYOX3B1bTn/G71E36lvcPM3fVnxDgja1zmctlW NuoN6sN8ivgP+sy8S2fvtTDOe74S0J8GumJXcW8l+mw4E8N7/f2mGkJlZym+gv9tfHM+i UQ1qvfRf+0yd1+2N1bfZVxHgGOugxPU6REPQ7olnISvPRhYweW+f6cfOyIM3/7IgRWw== 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=oUF0MT3p; 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 A2BAA606A321 for ; Wed, 11 Nov 2026 00:44:22 +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=oUF0MT3p Received: by smtp.kernel.org (Postfix) with ESMTPSA id BC80D1F0089F; Wed, 11 Nov 2026 00:44:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794357862; bh=cSR/TBey1iclnNGalSJzQTp/6lAl0LrfHGJZWIj5asA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=oUF0MT3pK7Hinse9tTEwHUbv2usvhT/wBOgYIKqbzkW/5jXkHiDZzt8dME5QRLmRJ KewzgZ33ZYPlQNHbNJWE9oh7Z7gmLWcAJffSXmO3cgAKO7QCwnJjZzrw/MHXkOx4DX s1ioqQ4mBbY13TlxaCXFbYsPxosrBDFxD8PkeCH/sjn0GsaPaYqyRYUbn8SnuyTTG+ Ik58DKyPrgfd8DSqFNW8Zuvw3i4w7pA0+OlReoWsP7dhpqxthe2y+qxT/w5kcJ8Y78 ZYTggVG2BKGKuzrmpJlHKVJQSB1fCKCemdwZFCKUok0N3SSqCm4aTuVmxADMrXyOlv xj/fQHy0SywGg== From: Sasha Levin To: stable@vger.kernel.org Cc: Wentao Liang , Juergen Gross , Sasha Levin Subject: [PATCH 5.15.y] xen/gntdev: Fix gntdev_dmabuf ref leak in dmabuf_exp_wait_released() Date: Tue, 10 Nov 2026 19:44:20 -0500 Message-ID: <20261111004341.313788-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261107060336-failed-5.15-6f165abe2b40@kernel.org> References: <20261107060336-failed-5.15-6f165abe2b40@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