RE: Buffer overread in pv88090-regulator.ko
From: James Seong-Won Ban
Date: Tue Aug 01 2017 - 22:44:12 EST
I have not thought this driver should be loaded for any malicious device.
Anyway we will update it.
> -----Original Message-----
> From: Anton Vasilyev [mailto:vasilyev@xxxxxxxxx]
> Sent: Wednesday, August 02, 2017 1:06 AM
> To: James Seong-Won Ban
> Cc: Liam Girdwood; Mark Brown; linux-kernel@xxxxxxxxxxxxxxx; ldv-
> Subject: Buffer overread in pv88090-regulator.ko
> While searching for memory errors in Linux kernel I've come across
> drivers/regulator/pv88090-regulator.ko module.
> Buffer overread could occur at pv88090_i2c_probe():
> If read from malicious device such values for conf2 and range (e.g. 0x10000000
> and 0x1000 for PV88090_ID_BUCK2) that
> conf2 = (conf2 >> PV88090_BUCK_VDAC_RANGE_SHIFT) &
> PV88090_BUCK_VDAC_RANGE_MASK; and
> range = (range >>
> (PV88080_BUCK_VRANGE_GAIN_SHIFT + i - 1)) &
> PV88080_BUCK_VRANGE_GAIN_MASK; become 1 then
> index = ((range << 1) | conf2); become 3, but index is used for
> dereference pv88090_buck_vol.
> Should be index=3 considered as incorrect value and pv88090_i2c_probe() must
> return error, or pv88090_buck_vol should be expanded?
> Found by Linux Driver Verification project (linuxtesting.org).
> Anton Vasilyev
> Linux Verification Center, ISPRAS
> web: http://linuxtesting.org
> e-mail: vasilyev@xxxxxxxxx