[SRU][N][PATCH 0/1] CVE-2024-50249

[Massimiliano Pellizzer]

[Impact]

ACPI: CPPC: Make rmw_lock a raw_spin_lock

sugov_update_shared() locks a raw_spinlock while cpc_write() locks a
spinlock.

To have a correct wait-type order, update rmw_lock to a raw spinlock and
ensure that interrupts will be disabled on the CPU holding it.

[Fix]

Oracular: Fixed via upstream stable updates (3273c89a8e2784)
Noble: Clean cherry-pick from upstream
Jammy: Fixed via upstream stable updates (7c9ca4d728f563)
Focal: Not affected
Bionic: Not affected
Xenial: Not affected
Trusty: Not affected

[Test Case]

Compile and boot tested.

[Where problems could occur]

The fix affects the CPPC driver. An issue with this fix may lead to
instability in CPU performance scaling and power management
functionality. A normal user might experience performance degradation,
unexpected CPU throttling, increased power consumption, or system
instability during high-performance workloads or when switching power
states.

Pierre Gondois (1):
  ACPI: CPPC: Make rmw_lock a raw_spin_lock

 drivers/acpi/cppc_acpi.c | 9 +++++----
 include/acpi/cppc_acpi.h | 2 +-
 2 files changed, 6 insertions(+), 5 deletions(-)

-- 
2.43.0