CVE-2021-47386 Information

Description

In the Linux kernel the following vulnerability has been resolved:

hwmon: (w83791d) Fix NULL pointer dereference by removing unnecessary structure field

If driver read val value sufficient for (val & 0x08) && (!(val & 0x80)) && ((val & 0x7) == ((val » 4) & 0x7)) from device then Null pointer dereference occurs. (It is possible if tmp = 0b0xyz1xyz where same literals mean same numbers) Also lm75[] does not serve a purpose anymore after switching to devm_i2c_new_dummy_device() in w83791d_detect_subclients().

The patch fixes possible NULL pointer dereference by removing lm75[].

Found by Linux Driver Verification project (linuxtesting.org).

[groeck: Dropped unnecessary continuation lines fixed multi-line alignment]

Reference

https://git.kernel.org/stable/c/44d3c480e4e2a75bf6296a18b4356157991ccd80 https://git.kernel.org/stable/c/516d9055039017a20a698103be2b556b4c976bb8 https://git.kernel.org/stable/c/16887ae4e3defd2c4e7913b6c539f33eaf4eac5c https://git.kernel.org/stable/c/943c15ac1b84d378da26bba41c83c67e16499ac4