CVE-2024-35995: ACPI: CPPC: Use access_width over bit_width for system memory accesses

Description

In the Linux kernel, the following vulnerability has been resolved:

ACPI: CPPC: Use access_width over bit_width for system memory accesses

To align with ACPI 6.3+, since bit_width can be any 8-bit value, it
cannot be depended on to be always on a clean 8b boundary. This was
uncovered on the Cobalt 100 platform.

SError Interrupt on CPU26, code 0xbe000011 -- SError
CPU: 26 PID: 1510 Comm: systemd-udevd Not tainted 5.15.2.1-13 #1
Hardware name: MICROSOFT CORPORATION, BIOS MICROSOFT CORPORATION
pstate: 62400009 (nZCv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
pc : cppc_get_perf_caps+0xec/0x410
lr : cppc_get_perf_caps+0xe8/0x410
sp : ffff8000155ab730
x29: ffff8000155ab730 x28: ffff0080139d0038 x27: ffff0080139d0078
x26: 0000000000000000 x25: ffff0080139d0058 x24: 00000000ffffffff
x23: ffff0080139d0298 x22: ffff0080139d0278 x21: 0000000000000000
x20: ffff00802b251910 x19: ffff0080139d0000 x18: ffffffffffffffff
x17: 0000000000000000 x16: ffffdc7e111bad04 x15: ffff00802b251008
x14: ffffffffffffffff x13: ffff013f1fd63300 x12: 0000000000000006
x11: ffffdc7e128f4420 x10: 0000000000000000 x9 : ffffdc7e111badec
x8 : ffff00802b251980 x7 : 0000000000000000 x6 : ffff0080139d0028
x5 : 0000000000000000 x4 : ffff0080139d0018 x3 : 00000000ffffffff
x2 : 0000000000000008 x1 : ffff8000155ab7a0 x0 : 0000000000000000
Kernel panic - not syncing: Asynchronous SError Interrupt
CPU: 26 PID: 1510 Comm: systemd-udevd Not tainted
5.15.2.1-13 #1
Hardware name: MICROSOFT CORPORATION, BI...

Classification

CVE ID: CVE-2024-35995

Affected Products

Vendor: Linux

Product: Linux

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.05% (probability of being exploited)

EPSS Percentile: 17.97% (scored less or equal to compared to others)

EPSS Date: 2025-02-21 (when was this score calculated)

References

https://git.kernel.org/stable/c/01fc53be672acae37e611c80cc0b4f3939584de3
https://git.kernel.org/stable/c/1b890ae474d19800a6be1696df7fb4d9a41676e4
https://git.kernel.org/stable/c/6cb6b12b78dcd8867a3fdbb1b6d0ed1df2b208d1
https://git.kernel.org/stable/c/2f4a4d63a193be6fd530d180bb13c3592052904c

Timeline