Messages in this thread | | | Date | Fri, 2 Jun 2023 08:41:47 +0200 | From | zzam@gentoo ... | Subject | Re: [PATCH 05/24] media: dvb-usb-v2: ec168: fix null-ptr-deref in ec168_i2c_xfer() |
| |
Am 19.05.23 um 11:17 schrieb Wei Chen: > Dear Linux Developers, > Hi Wei, > Thank you for the review for my patch in driver az6027 and ec168. > > Yes, I agree with you. Sorry for my mistake. Since these two patches has > already been accepted and merged in git tree media, should I send a new > patch to revise this problem? Or how could I revise an accepted patch?
I think the best is to send new patches on top of the already accepted patches.
Regards Matthias
> > Thanks, > Wei > > > ------ Original Message ------ >> From zzam@gentoo.org > To "Mauro Carvalho Chehab" <mchehab@kernel.org> > Cc "Wei Chen" <harperchen1110@gmail.com>; "Antti Palosaari" > <crope@iki.fi>; linux-kernel@vger.kernel.org; linux-media@vger.kernel.org > Date 2023/5/17 13:10:34 > Subject Re: [PATCH 05/24] media: dvb-usb-v2: ec168: fix null-ptr-deref > in ec168_i2c_xfer() > >> Am 13.05.23 um 19:57 schrieb Mauro Carvalho Chehab: >>> From: Wei Chen <harperchen1110@gmail.com> >>> >>> In ec168_i2c_xfer, msg is controlled by user. When msg[i].buf is null >>> and msg[i].len is zero, former checks on msg[i].buf would be passed. >>> If accessing msg[i].buf[0] without sanity check, null pointer deref >>> would happen. We add check on msg[i].len to prevent crash. >>> >>> Similar commit: >>> commit 0ed554fd769a ("media: dvb-usb: az6027: fix null-ptr-deref in >>> az6027_i2c_xfer()") >>> >> Review comment below. >> >>> Link: >>> https://lore.kernel.org/linux-media/20230313085853.3252349-1-harperchen1110@gmail.com >>> Signed-off-by: Wei Chen <harperchen1110@gmail.com> >>> Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org> >>> --- >>> drivers/media/usb/dvb-usb-v2/ec168.c | 12 ++++++++++++ >>> 1 file changed, 12 insertions(+) >>> >>> diff --git a/drivers/media/usb/dvb-usb-v2/ec168.c >>> b/drivers/media/usb/dvb-usb-v2/ec168.c >>> index 7ed0ab9e429b..0e4773fc025c 100644 >>> --- a/drivers/media/usb/dvb-usb-v2/ec168.c >>> +++ b/drivers/media/usb/dvb-usb-v2/ec168.c >>> @@ -115,6 +115,10 @@ static int ec168_i2c_xfer(struct i2c_adapter >>> *adap, struct i2c_msg msg[], >>> while (i < num) { >>> if (num > i + 1 && (msg[i+1].flags & I2C_M_RD)) { >>> if (msg[i].addr == ec168_ec100_config.demod_address) { >>> + if (msg[i].len < 1) { >>> + i = -EOPNOTSUPP; >>> + break; >>> + } >>> req.cmd = READ_DEMOD; >>> req.value = 0; >>> req.index = 0xff00 + msg[i].buf[0]; /* reg */ >>> @@ -131,6 +135,10 @@ static int ec168_i2c_xfer(struct i2c_adapter >>> *adap, struct i2c_msg msg[], >>> } >>> } else { >>> if (msg[i].addr == ec168_ec100_config.demod_address) { >>> + if (msg[i].len < 1) { >>> + i = -EOPNOTSUPP; >>> + break; >>> + } >> The check condition should be msg[i].len < 2 or != 2. The following >> lines access msg[i].buf elements 0 and 1. >>> req.cmd = WRITE_DEMOD; >>> req.value = msg[i].buf[1]; /* val */ >>> req.index = 0xff00 + msg[i].buf[0]; /* reg */ >>> @@ -139,6 +147,10 @@ static int ec168_i2c_xfer(struct i2c_adapter >>> *adap, struct i2c_msg msg[], >>> ret = ec168_ctrl_msg(d, &req); >>> i += 1; >>> } else { >>> + if (msg[i].len < 1) { >>> + i = -EOPNOTSUPP; >>> + break; >>> + } >>> req.cmd = WRITE_I2C; >>> req.value = msg[i].buf[0]; /* val */ >>> req.index = 0x0100 + msg[i].addr; /* I2C addr */ >>
| |