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 F34DF1863 for ; Wed, 28 Dec 2022 15:38:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 794EAC433D2; Wed, 28 Dec 2022 15:38:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1672241915; bh=kl9t3VKFk9KL5Sokgh4hA/Dvd50iPx2j8/AN9euXYsY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gTO0Ft9vztGlcgpTRZHW14gWXChXAvfT0Us/7sTFtn1v+/9AbKqEuy1ppi9Uf5UK1 sacXqq+oF9Pu/XjVZMULYciyJQfjouRMieL9cRBsGe4VCDM+3PPxp8dg1bIP2yQ8Hd 5jakoKXRXsPJqFb38sUUrOUr7649Y/Woe6XsWHHI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chen Zhongjin , Hans Verkuil , Sasha Levin Subject: [PATCH 6.0 0343/1073] media: vidtv: Fix use-after-free in vidtv_bridge_dvb_init() Date: Wed, 28 Dec 2022 15:32:11 +0100 Message-Id: <20221228144337.323006142@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20221228144328.162723588@linuxfoundation.org> References: <20221228144328.162723588@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Chen Zhongjin [ Upstream commit ba8d9405935097e296bcf7a942c3a01df0edb865 ] KASAN reports a use-after-free: BUG: KASAN: use-after-free in dvb_dmxdev_release+0x4d5/0x5d0 [dvb_core] Call Trace: ... dvb_dmxdev_release+0x4d5/0x5d0 [dvb_core] vidtv_bridge_probe+0x7bf/0xa40 [dvb_vidtv_bridge] platform_probe+0xb6/0x170 ... Allocated by task 1238: ... dvb_register_device+0x1a7/0xa70 [dvb_core] dvb_dmxdev_init+0x2af/0x4a0 [dvb_core] vidtv_bridge_probe+0x766/0xa40 [dvb_vidtv_bridge] ... Freed by task 1238: dvb_register_device+0x6d2/0xa70 [dvb_core] dvb_dmxdev_init+0x2af/0x4a0 [dvb_core] vidtv_bridge_probe+0x766/0xa40 [dvb_vidtv_bridge] ... It is because the error handling in vidtv_bridge_dvb_init() is wrong. First, vidtv_bridge_dmx(dev)_init() will clean themselves when fail, but goto fail_dmx(_dev): calls release functions again, which causes use-after-free. Also, in fail_fe, fail_tuner_probe and fail_demod_probe, j = i will cause out-of-bound when i finished its loop (i == NUM_FE). And the loop releasing is wrong, although now NUM_FE is 1 so it won't cause problem. Fix this by correctly releasing everything. Fixes: f90cf6079bf6 ("media: vidtv: add a bridge driver") Signed-off-by: Chen Zhongjin Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin --- .../media/test-drivers/vidtv/vidtv_bridge.c | 22 +++++++------------ 1 file changed, 8 insertions(+), 14 deletions(-) diff --git a/drivers/media/test-drivers/vidtv/vidtv_bridge.c b/drivers/media/test-drivers/vidtv/vidtv_bridge.c index 82620613d56b..dff7265a42ca 100644 --- a/drivers/media/test-drivers/vidtv/vidtv_bridge.c +++ b/drivers/media/test-drivers/vidtv/vidtv_bridge.c @@ -459,26 +459,20 @@ static int vidtv_bridge_dvb_init(struct vidtv_dvb *dvb) for (j = j - 1; j >= 0; --j) dvb->demux.dmx.remove_frontend(&dvb->demux.dmx, &dvb->dmx_fe[j]); -fail_dmx_dev: dvb_dmxdev_release(&dvb->dmx_dev); -fail_dmx: +fail_dmx_dev: dvb_dmx_release(&dvb->demux); +fail_dmx: +fail_demod_probe: + for (i = i - 1; i >= 0; --i) { + dvb_unregister_frontend(dvb->fe[i]); fail_fe: - for (j = i; j >= 0; --j) - dvb_unregister_frontend(dvb->fe[j]); + dvb_module_release(dvb->i2c_client_tuner[i]); fail_tuner_probe: - for (j = i; j >= 0; --j) - if (dvb->i2c_client_tuner[j]) - dvb_module_release(dvb->i2c_client_tuner[j]); - -fail_demod_probe: - for (j = i; j >= 0; --j) - if (dvb->i2c_client_demod[j]) - dvb_module_release(dvb->i2c_client_demod[j]); - + dvb_module_release(dvb->i2c_client_demod[i]); + } fail_adapter: dvb_unregister_adapter(&dvb->adapter); - fail_i2c: i2c_del_adapter(&dvb->i2c_adapter); -- 2.35.1