Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752893AbaB1VXX (ORCPT ); Fri, 28 Feb 2014 16:23:23 -0500 Received: from qmta05.emeryville.ca.mail.comcast.net ([76.96.30.48]:53313 "EHLO qmta05.emeryville.ca.mail.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752724AbaB1VXJ (ORCPT ); Fri, 28 Feb 2014 16:23:09 -0500 From: Shuah Khan To: m.chehab@samsung.com Cc: Shuah Khan , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, shuahkhan@gmail.com Subject: [PATCH 3/3] media/drx39xyj: fix boot failure due to null pointer dereference Date: Fri, 28 Feb 2014 14:23:02 -0700 Message-Id: X-Mailer: git-send-email 1.8.3.2 In-Reply-To: References: In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org DJH_DEBUG only code path in drxbsp_i2c_write_read() dereferences w_dev_addr and subsequently w_dev_addr->user_data->i2c which results in failure during boot. This patch fixes the null pointer derefence bug as well as the following compile errors: LD arch/x86/built-in.o CC drivers/media/dvb-frontends/drx39xyj/drxj.o drivers/media/dvb-frontends/drx39xyj/drxj.c: In function ‘drxbsp_i2c_write_read’: drivers/media/dvb-frontends/drx39xyj/drxj.c:1558:25: error: redeclaration of ‘state’ with no linkage struct drx39xxj_state *state = w_dev_addr->user_data; ^ drivers/media/dvb-frontends/drx39xyj/drxj.c:1512:25: note: previous declaration of ‘state’ was here struct drx39xxj_state *state; ^ drivers/media/dvb-frontends/drx39xyj/drxj.c:1558:2: warning: ISO C90 forbids mixed declarations and code [-Wdeclaration-after-statement] struct drx39xxj_state *state = w_dev_addr->user_data; ^ drivers/media/dvb-frontends/drx39xyj/drxj.c:1560:17: error: redeclaration of ‘msg’ with no linkage struct i2c_msg msg[2] = { ^ drivers/media/dvb-frontends/drx39xyj/drxj.c:1513:17: note: previous declaration of ‘msg’ was here struct i2c_msg msg[2]; ^ Signed-off-by: Shuah Khan --- drivers/media/dvb-frontends/drx39xyj/drxj.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/drivers/media/dvb-frontends/drx39xyj/drxj.c b/drivers/media/dvb-frontends/drx39xyj/drxj.c index 72c541a..585d891 100644 --- a/drivers/media/dvb-frontends/drx39xyj/drxj.c +++ b/drivers/media/dvb-frontends/drx39xyj/drxj.c @@ -1551,14 +1551,23 @@ int drxbsp_i2c_write_read(struct i2c_device_addr *w_dev_addr, } #ifdef DJH_DEBUG - struct drx39xxj_state *state = w_dev_addr->user_data; + if (w_dev_addr == NULL || r_dev_addr == NULL) + return 0; - struct i2c_msg msg[2] = { - {.addr = w_dev_addr->i2c_addr, - .flags = 0, .buf = wData, .len = w_count}, - {.addr = r_dev_addr->i2c_addr, - .flags = I2C_M_RD, .buf = r_data, .len = r_count}, - }; + state = w_dev_addr->user_data; + + if (state->i2c == NULL) + return 0; + + msg[0].addr = w_dev_addr->i2c_addr; + msg[0].flags = 0; + msg[0].buf = wData; + msg[0].len = w_count; + msg[1].addr = r_dev_addr->i2c_addr; + msg[1].flags = I2C_M_RD; + msg[1].buf = r_data; + msg[1].len = r_count; + num_msgs = 2; pr_debug("drx3933 i2c operation addr=%x i2c=%p, wc=%x rc=%x\n", w_dev_addr->i2c_addr, state->i2c, w_count, r_count); -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/