From: Alex Guo <alexguo1023@gmail.com> stable inclusion from stable-v5.10.241 commit b3d77a3fc71c084575d3df4ec6544b3fb6ce587d category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ICWGG3 CVE: CVE-2025-38693 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit ed0234c8458b3149f15e496b48a1c9874dd24a1b ] 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 <alexguo1023@gmail.com> Link: https://lore.kernel.org/r/20250616013353.738790-1-alexguo1023@gmail.com Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Conflicts: drivers/media/dvb-frontends/dib7000p.c [The conflicts were due to a compilation error in the original community patch.] Signed-off-by: Xiaomeng Zhang <zhangxiaomeng13@huawei.com> --- drivers/media/dvb-frontends/dib7000p.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/media/dvb-frontends/dib7000p.c b/drivers/media/dvb-frontends/dib7000p.c index 1f0b0690198e..d57d47bd6af7 100644 --- a/drivers/media/dvb-frontends/dib7000p.c +++ b/drivers/media/dvb-frontends/dib7000p.c @@ -2198,7 +2198,11 @@ 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; - u16 serpar_num = msg[0].buf[0]; + u16 serpar_num; + + if (msg[0].len < 3) + return -EOPNOTSUPP; + serpar_num = msg[0].buf[0]; while (n_overflow == 1 && i) { n_overflow = (dib7000p_read_word(state, 1984) >> 1) & 0x1; @@ -2217,9 +2221,13 @@ 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; - u16 serpar_num = msg[0].buf[0]; + u16 serpar_num; u16 read_word; + if (msg[0].len < 1 || msg[1].len < 2) + return -EOPNOTSUPP; + serpar_num = msg[0].buf[0]; + while (n_overflow == 1 && i) { n_overflow = (dib7000p_read_word(state, 1984) >> 1) & 0x1; i--; -- 2.34.1