CVE-2024-57986 Information

Description

In the Linux kernel the following vulnerability has been resolved:

HID: core: Fix assumption that Resolution Multipliers must be in Logical Collections

A report in 2019 by the syzbot fuzzer was found to be connected to two errors in the HID core associated with Resolution Multipliers. One of the errors was fixed by commit ea427a222d8b (\HID: core: Fix deadloop in hid_apply_multiplier.) but the other has not been fixed.

This error arises because hid_apply_multipler() assumes that every Resolution Multiplier control is contained in a Logical Collection i.e. there’s no way the routine can ever set multiplier_collection to NULL. This is in spite of the fact that the function starts with a big comment saying:

  \The Resolution Multiplier control must be contained in the same
  Logical Collection as the control(s) to which it is to be applied.
   ...
   If no Logical Collection is
  defined the Resolution Multiplier is associated with all
  controls in the report.\n	  HID Usage Table v1.12 Section 4.3.1 p30
 
  Thus search from the current collection upwards until we find a
  logical collection...

The comment and the code overlook the possibility that none of the collections found may be a Logical Collection.

The fix is to set the multiplier_collection pointer to NULL if the collection found isn’t a Logical Collection.

Reference

https://git.kernel.org/stable/c/64f2657b579343cf923aa933f08074e6258eb07b https://git.kernel.org/stable/c/a5498f1f864ea26f4c613c77f54409c776a95a90 https://git.kernel.org/stable/c/bebf542e8d7c44a18a95f306b1b5dc160c823506 https://git.kernel.org/stable/c/ebaeca33d32c8bdb705a8c88267737a456f354b1 https://git.kernel.org/stable/c/ed3d3883476423f337aac0f22c521819b3f1e970