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=1794632909; b=YBLxXy6iLPxk67al+joSVFuq29HLgXY2pC73TvD34PTYekjQVXqn9SFsI4EZNGSczRMA EkRnQMo4LP13h/+7FVapAMnxX4ZesZq/x75BF9zHezjGzLSFgPpse5KOe1q5XKTCKo191 sPtbt3lJfb+m3mc3clXm7tJ71vbWN2L0LURMSLrtxp6+hgtJakgxowhTN0KCXGe4mYfaO ZbBVlZ/1QXyVbsIR/fAAuhIh9Xr0zQAZhrArLMWfdMcK0VYgtDk3LgnCtndn3KtovRFsL Y9fc8JH0N0/4Yf/MXoTc2EQns8Cemh25PHXXzRfb8bR2R5Mu/szgNUvtegEsmnVj0/Q== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794632909; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=s3tqao3gu78L5JXeH7aKRsHMDDcpMOgJCMMXmjvHGxg=; b=i09WkmAcDY9dKgGhHCF3xYGb+uuy3aUDlBh83cwTIgpqRW5Ohyyt5vpW7cgOEmE8B1r+ pANoOjYb0lDowODZQ+mJdztMPZ5geMpOB4Cdr2YGGhkl7TWdV0wRY/9+qAMpjGK9tB/AR nkncXtUhE+h+kv77Ho2a2+gr7GzeHtqio0E7NKtqxlPkAy7vCj18iDXu+Ho/u4k/qnP7K 5T1sZQJyWNd62QhvYv3QgmjGOROS5dBepuNeM3QGX9vinSL3J7jyp5RsVO2sVzT+jR+4R hvHvj2Wne9oApDaTdl85cuJwLMd/K6tkd6oFWSy0Get4n49Id8GAYYd1DWOXFHTWHvA== 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=LbzCkTwv; 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 476BD606A323 for ; Sat, 14 Nov 2026 05:08:28 +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=LbzCkTwv Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3C1661F000C4; Sat, 14 Nov 2026 05:08:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794632908; bh=s3tqao3gu78L5JXeH7aKRsHMDDcpMOgJCMMXmjvHGxg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=LbzCkTwvQJUWGAYWXwfcXsz74WbT6MUEsmq8/HhU/0kt7Ya6QR3ac9+9EhjLQ2RVi /rLpujl63B8sl2z5JhnOXnf5BDSy9UHjM22PkMZss1GIi9DN9iCh21O2gf1w5Wvyaz TMRA0ZXHdb699J76+ah6T780rjcba/gXnaJIv7dO9m0pIR1VPtTOUuvzAA4xQFOT1z JOq7lvIsfT6fWzGS2sRTpLWvSCzBHSKS184Pp3ryKrKW3j/L96dX+idYWpOCc2+8EU uxN7vQA83y89oZETtppTtzP9ho/N1zhO4md32OxjUysChm8Xg0FUjSe+F45QLIpJzk S0ajCMMW12MXg== From: Sasha Levin To: stable@vger.kernel.org Cc: Thorsten Blum , PrasannaKumar Muralidharan , "Michael S. Tsirkin" , Sasha Levin Subject: [PATCH 5.15.y] hwrng: virtio - prevent use-after-free after a failed restore Date: Sat, 14 Nov 2026 00:08:27 -0500 Message-ID: <20261114050812.2912148-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261109202248-failed-5.15-0f7bf47f5a0c@kernel.org> References: <20261109202248-failed-5.15-0f7bf47f5a0c@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: Thorsten Blum [ Upstream commit 0f7bf47f5a0cc26320aa4b14f4504d03a07f4b74 ] remove_common() frees the driver data during freeze, but does not clear vdev->priv, which points to freed memory. If probe_common() then fails during restore, a later remove or freeze can dereference the dangling pointer. Clear vdev->priv on the probe_common() error cleanup path and before freeing the driver data in remove_common(). Also reset the device and return early from remove_common() if vdev->priv is already NULL for a safe teardown after a failed restore. Fixes: 08e53fbdb85c ("virtio-rng: support multiple virtio-rng devices") Cc: stable@vger.kernel.org Signed-off-by: Thorsten Blum Reviewed-by: PrasannaKumar Muralidharan . Signed-off-by: Michael S. Tsirkin Message-ID: <20261016103640.4989-2-blum@kernel.org> [ sashal: Replaced virtio_reset_device(vdev) with the existing vdev->config->reset(vdev) callback. ] Signed-off-by: Sasha Levin --- drivers/char/hw_random/virtio-rng.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c index f6c0de82c22bc..72c99fa35e78d 100644 --- a/drivers/char/hw_random/virtio-rng.c +++ b/drivers/char/hw_random/virtio-rng.c @@ -186,6 +186,7 @@ static int probe_common(struct virtio_device *vdev) err_find: ida_simple_remove(&rng_index_ida, index); err_ida: + vdev->priv = NULL; kfree(vi); return err; } @@ -194,6 +195,11 @@ static void remove_common(struct virtio_device *vdev) { struct virtrng_info *vi = vdev->priv; + if (!vi) { + vdev->config->reset(vdev); + return; + } + vi->hwrng_removed = true; vi->data_avail = 0; vi->data_idx = 0; @@ -203,6 +209,7 @@ static void remove_common(struct virtio_device *vdev) hwrng_unregister(&vi->hwrng); vdev->config->del_vqs(vdev); ida_simple_remove(&rng_index_ida, vi->index); + vdev->priv = NULL; kfree(vi); } -- 2.53.0