From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 A1ACC183CD4; Mon, 12 Aug 2024 16:29:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723480158; cv=none; b=ejqm3zxkOnHb7PODv6D2e8qy1HcsVR8hY5Vz0Hf5e6RttpNsZltUhGiteaCRvKgGPogKPSsXgpwb/j5FHZZV28FxlLme0CXymJRZBswKGzpfYoeywpqGUWwC56E9Vz6F84aSB+o+M0NT+rMZr2igroXqks0xhShmj/XOaNf0LCQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723480158; c=relaxed/simple; bh=nb2mpv8KF6u31meg6HQwqQL9m3dYdo75G/GttHQdv/s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=K+deCojzxuCb887F6NvVGQDD3oy1oMjgtSfyM61rggjbZhmHD7PwTr1BSAIcs0W0+jRUQIoXsYWse0Za7opfzLyuVRdYBjprmHAjl+lwxqumwWoqu0um65wfMhxMMYWktRB+RGKGSvphGk1nZE/h8WTtHBvI2EEW0Fh3IO2H2Po= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=SjiUC5iK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="SjiUC5iK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 15AD2C32782; Mon, 12 Aug 2024 16:29:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1723480158; bh=nb2mpv8KF6u31meg6HQwqQL9m3dYdo75G/GttHQdv/s=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SjiUC5iKbV9hEo2/GxX8BytTh08A3e/T1Tc+ixkSQK+wHlzJzG2aKRAZlThRAiy6Q eeY+l3RTXlzSrsLre2VDxUTD/r4CexFwamXNa4eQMEapRBHGwchpAnOyThxw1SqJ2Q swQ3ZJdNQ2ID7HVQQE+menp4iYd6docpPyjhZPh4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chi Zhiling , Hans Verkuil , Sasha Levin Subject: [PATCH 6.10 111/263] media: xc2028: avoid use-after-free in load_firmware_cb() Date: Mon, 12 Aug 2024 18:01:52 +0200 Message-ID: <20240812160150.795554984@linuxfoundation.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240812160146.517184156@linuxfoundation.org> References: <20240812160146.517184156@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chi Zhiling [ Upstream commit 68594cec291ff9523b9feb3f43fd853dcddd1f60 ] syzkaller reported use-after-free in load_firmware_cb() [1]. The reason is because the module allocated a struct tuner in tuner_probe(), and then the module initialization failed, the struct tuner was released. A worker which created during module initialization accesses this struct tuner later, it caused use-after-free. The process is as follows: task-6504 worker_thread tuner_probe <= alloc dvb_frontend [2] ... request_firmware_nowait <= create a worker ... tuner_remove <= free dvb_frontend ... request_firmware_work_func <= the firmware is ready load_firmware_cb <= but now the dvb_frontend has been freed To fix the issue, check the dvd_frontend in load_firmware_cb(), if it is null, report a warning and just return. [1]: ================================================================== BUG: KASAN: use-after-free in load_firmware_cb+0x1310/0x17a0 Read of size 8 at addr ffff8000d7ca2308 by task kworker/2:3/6504 Call trace: load_firmware_cb+0x1310/0x17a0 request_firmware_work_func+0x128/0x220 process_one_work+0x770/0x1824 worker_thread+0x488/0xea0 kthread+0x300/0x430 ret_from_fork+0x10/0x20 Allocated by task 6504: kzalloc tuner_probe+0xb0/0x1430 i2c_device_probe+0x92c/0xaf0 really_probe+0x678/0xcd0 driver_probe_device+0x280/0x370 __device_attach_driver+0x220/0x330 bus_for_each_drv+0x134/0x1c0 __device_attach+0x1f4/0x410 device_initial_probe+0x20/0x30 bus_probe_device+0x184/0x200 device_add+0x924/0x12c0 device_register+0x24/0x30 i2c_new_device+0x4e0/0xc44 v4l2_i2c_new_subdev_board+0xbc/0x290 v4l2_i2c_new_subdev+0xc8/0x104 em28xx_v4l2_init+0x1dd0/0x3770 Freed by task 6504: kfree+0x238/0x4e4 tuner_remove+0x144/0x1c0 i2c_device_remove+0xc8/0x290 __device_release_driver+0x314/0x5fc device_release_driver+0x30/0x44 bus_remove_device+0x244/0x490 device_del+0x350/0x900 device_unregister+0x28/0xd0 i2c_unregister_device+0x174/0x1d0 v4l2_device_unregister+0x224/0x380 em28xx_v4l2_init+0x1d90/0x3770 The buggy address belongs to the object at ffff8000d7ca2000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 776 bytes inside of 2048-byte region [ffff8000d7ca2000, ffff8000d7ca2800) The buggy address belongs to the page: page:ffff7fe00035f280 count:1 mapcount:0 mapping:ffff8000c001f000 index:0x0 flags: 0x7ff800000000100(slab) raw: 07ff800000000100 ffff7fe00049d880 0000000300000003 ffff8000c001f000 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8000d7ca2200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8000d7ca2280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8000d7ca2300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8000d7ca2380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8000d7ca2400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== [2] Actually, it is allocated for struct tuner, and dvb_frontend is inside. Signed-off-by: Chi Zhiling Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin --- drivers/media/tuners/xc2028.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/media/tuners/xc2028.c b/drivers/media/tuners/xc2028.c index 5a967edceca93..352b8a3679b72 100644 --- a/drivers/media/tuners/xc2028.c +++ b/drivers/media/tuners/xc2028.c @@ -1361,9 +1361,16 @@ static void load_firmware_cb(const struct firmware *fw, void *context) { struct dvb_frontend *fe = context; - struct xc2028_data *priv = fe->tuner_priv; + struct xc2028_data *priv; int rc; + if (!fe) { + pr_warn("xc2028: No frontend in %s\n", __func__); + return; + } + + priv = fe->tuner_priv; + tuner_dbg("request_firmware_nowait(): %s\n", fw ? "OK" : "error"); if (!fw) { tuner_err("Could not load firmware %s.\n", priv->fname); -- 2.43.0