From 1ad77b5c29b19c633afaaabf268acedca79aa818 Mon Sep 17 00:00:00 2001 From: Shuah Khan Date: Fri, 28 Feb 2014 18:23:02 -0300 Subject: [PATCH] [media] drx-j: fix boot failure due to null pointer dereference MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Acked-by: Devin Heitmueller Signed-off-by: Mauro Carvalho Chehab --- 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 72c541a3c6c0..585d891392c3 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); -- 2.20.1