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| author | Wei Chen <harperchen1110@gmail.com> | 2023-03-10 16:56:04 +0000 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@kernel.org> | 2023-05-14 06:29:42 +0100 |
| commit | 858e97d7956d17a2cb56a9413468704a4d5abfe1 (patch) | |
| tree | 6d521428648105a5149e8aeaead11faa3a4f2006 | |
| parent | 0f5bb36bf9b39a2a96e730bf4455095b50713f63 (diff) | |
| download | linux-858e97d7956d17a2cb56a9413468704a4d5abfe1.tar.gz | |
media: dvb-usb: az6027: fix three null-ptr-deref in az6027_i2c_xfer()
In az6027_i2c_xfer, msg is controlled by user. When msg[i].buf is null,
commit 0ed554fd769a ("media: dvb-usb: az6027: fix null-ptr-deref in
az6027_i2c_xfer()") fix the null-ptr-deref bug when msg[i].addr is 0x99.
However, null-ptr-deref also happens when msg[i].addr is 0xd0 and 0xc0.
We add check on msg[i].len to prevent null-ptr-deref.
Link: https://lore.kernel.org/linux-media/20230310165604.3093483-1-harperchen1110@gmail.com
Signed-off-by: Wei Chen <harperchen1110@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
| -rw-r--r-- | drivers/media/usb/dvb-usb/az6027.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/media/usb/dvb-usb/az6027.c b/drivers/media/usb/dvb-usb/az6027.c index 7d78ee09be5e1d..a31c6f82f4e90f 100644 --- a/drivers/media/usb/dvb-usb/az6027.c +++ b/drivers/media/usb/dvb-usb/az6027.c @@ -988,6 +988,10 @@ static int az6027_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int n /* write/read request */ if (i + 1 < num && (msg[i + 1].flags & I2C_M_RD)) { req = 0xB9; + if (msg[i].len < 1) { + i = -EOPNOTSUPP; + break; + } index = (((msg[i].buf[0] << 8) & 0xff00) | (msg[i].buf[1] & 0x00ff)); value = msg[i].addr + (msg[i].len << 8); length = msg[i + 1].len + 6; @@ -1001,6 +1005,10 @@ static int az6027_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int n /* demod 16bit addr */ req = 0xBD; + if (msg[i].len < 1) { + i = -EOPNOTSUPP; + break; + } index = (((msg[i].buf[0] << 8) & 0xff00) | (msg[i].buf[1] & 0x00ff)); value = msg[i].addr + (2 << 8); length = msg[i].len - 2; @@ -1026,6 +1034,10 @@ static int az6027_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msg[], int n } else { req = 0xBD; + if (msg[i].len < 1) { + i = -EOPNOTSUPP; + break; + } index = msg[i].buf[0] & 0x00FF; value = msg[i].addr + (1 << 8); length = msg[i].len - 1; |