From: Alex Guo Date: Mon, 16 Jun 2025 01:33:53 +0000 (-0400) Subject: media: dvb-frontends: w7090p: fix null-ptr-deref in w7090p_tuner_write_serpar and... X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ed0234c8458b3149f15e496b48a1c9874dd24a1b;p=thirdparty%2Flinux.git media: dvb-frontends: w7090p: fix null-ptr-deref in w7090p_tuner_write_serpar and w7090p_tuner_read_serpar In w7090p_tuner_write_serpar, msg is controlled by user. When msg[0].buf is null and msg[0].len is zero, former checks on msg[0].buf would be passed. If accessing msg[0].buf[2] without sanity check, null pointer deref would happen. We add check on msg[0].len to prevent crash. Similar commit: commit 0ed554fd769a ("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()") Signed-off-by: Alex Guo Link: https://lore.kernel.org/r/20250616013353.738790-1-alexguo1023@gmail.com Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/dvb-frontends/dib7000p.c b/drivers/media/dvb-frontends/dib7000p.c index b40daf2420469..2c2354dd547da 100644 --- a/drivers/media/dvb-frontends/dib7000p.c +++ b/drivers/media/dvb-frontends/dib7000p.c @@ -2193,6 +2193,8 @@ static int w7090p_tuner_write_serpar(struct i2c_adapter *i2c_adap, struct i2c_ms struct dib7000p_state *state = i2c_get_adapdata(i2c_adap); u8 n_overflow = 1; u16 i = 1000; + if (msg[0].len < 3) + return -EOPNOTSUPP; u16 serpar_num = msg[0].buf[0]; while (n_overflow == 1 && i) { @@ -2212,6 +2214,8 @@ static int w7090p_tuner_read_serpar(struct i2c_adapter *i2c_adap, struct i2c_msg struct dib7000p_state *state = i2c_get_adapdata(i2c_adap); u8 n_overflow = 1, n_empty = 1; u16 i = 1000; + if (msg[0].len < 1 || msg[1].len < 2) + return -EOPNOTSUPP; u16 serpar_num = msg[0].buf[0]; u16 read_word;