5.15-stable review patch. If anyone has any objections, please let me know.
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From: Alex Guo alexguo1023@gmail.com
[ 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 --- 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 8c426baf76ee..a4d060fb1bab 100644 --- a/drivers/media/dvb-frontends/dib7000p.c +++ b/drivers/media/dvb-frontends/dib7000p.c @@ -2261,8 +2261,12 @@ static int dib7090p_rw_on_apb(struct i2c_adapter *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;