CVE-2023-53474: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: x86/MCE/AMD: Use an u64 for bank_map Thee maximum number of MCA banks is 64 (MAX_NR_BANKS), see a0bc32b3cacf ("x86/mce: Increase maximum number of banks to 64"). However, the bank_map which contains a bitfield of which banks to initialize is of type unsigned int and that overflows when those bit numbers are >= 32, leading to UBSAN complaining correctly: UBSAN: shift-out-of-bounds in arch/x86/kernel/cpu/mce/amd.c:1365:38 shift exponent 32 is too large for 32-bit type 'int' Change the bank_map to a u64 and use the proper BIT_ULL() macro when modifying bits in there. [ bp: Rewrite commit message. ]

Affected products

• Linux Linux Kernel: from 5.10, before 5.10.180 (fixed in 5.10.180); from 5.11, before 5.15.111 (fixed in 5.15.111); from 5.16, before 6.1.28 (fixed in 6.1.28); from 6.2, before 6.2.15 (fixed in 6.2.15); from 6.3, before 6.3.2 (fixed in 6.3.2)

Published 2025-10-01. Last modified 2026-08-04.