From: Alex Guo <alexguo1023@gmail.com> stable inclusion from stable-v6.6.103 commit 09906650484a09b3a4d4b3d3065395856810becd category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ICWGG6 CVE: CVE-2025-38694 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit ce5cac69b2edac3e3246fee03e8f4c2a1075238b ] In dib7090p_rw_on_apb, 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 issue occurs when access msg[1].buf[0] and msg[1].buf[1]. Similar commit: commit 0ed554fd769a ("media: dvb-usb: az6027: fix null-ptr-deref in az6027_i2c_xfer()") Signed-off-by: Alex Guo <alexguo1023@gmail.com> Link: https://lore.kernel.org/r/20250616013231.730221-1-alexguo1023@gmail.com Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Lin Yujun <linyujun809@h-partners.com> --- drivers/media/dvb-frontends/dib7000p.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/media/dvb-frontends/dib7000p.c b/drivers/media/dvb-frontends/dib7000p.c index 444fe1c4bf2d..f94660dd9df0 100644 --- a/drivers/media/dvb-frontends/dib7000p.c +++ b/drivers/media/dvb-frontends/dib7000p.c @@ -2259,12 +2259,16 @@ static int dib7090p_rw_on_apb(struct i2c_adapter *i2c_adap, { struct dib7000p_state *state = i2c_get_adapdata(i2c_adap); u16 word; if (num == 1) { /* write */ + if (msg[0].len < 3) + return -EOPNOTSUPP; dib7000p_write_word(state, apb_address, ((msg[0].buf[1] << 8) | (msg[0].buf[2]))); } else { + if (msg[1].len < 2) + return -EOPNOTSUPP; word = dib7000p_read_word(state, apb_address); msg[1].buf[0] = (word >> 8) & 0xff; msg[1].buf[1] = (word) & 0xff; } -- 2.34.1