CVE-2022-50223: LoongArch: cpuinfo: Fix a warning for CONFIG_CPUMASK_OFFSTACK
In the Linux kernel, the following vulnerability has been resolved:
LoongArch: cpuinfo: Fix a warning for CONFIGCPUMASKOFFSTACK
When CONFIGCPUMASKOFFSTACK and CONFIGDEBUGPERCPUMAPS is selected, cpumaxbitswarn() generates a runtime warning similar as below while we show /proc/cpuinfo. Fix this by using nrcpuids (the runtime limit) instead of NRCPUS to iterate CPUs.
[ 3.052463] ------------[ cut here ]------------ [ 3.059679] WARNING: CPU: 3 PID: 1 at include/linux/cpumask.h:108 showcpuinfo+0x5e8/0x5f0 [ 3.070072] Modules linked in: efivarfs autofs4 [ 3.076257] CPU: 0 PID: 1 Comm: systemd Not tainted 5.19-rc5+ #1052 [ 3.084034] Hardware name: Loongson Loongson-3A5000-7A1000-1w-V0.1-CRB/Loongson-LS3A5000-7A1000-1w-EVB-V1.21, BIOS Loongson-UDK2018-V2.0.04082-beta7 04/27 [ 3.099465] Stack : 9000000100157b08 9000000000f18530 9000000000cf846c 9000000100154000 [ 3.109127] 9000000100157a50 0000000000000000 9000000100157a58 9000000000ef7430 [ 3.118774] 90000001001578e8 0000000000000040 0000000000000020 ffffffffffffffff [ 3.128412] 0000000000aaaaaa 1ab25f00eec96a37 900000010021de80 900000000101c890 [ 3.138056] 0000000000000000 0000000000000000 0000000000000000 0000000000aaaaaa [ 3.147711] ffff8000339dc220 0000000000000001 0000000006ab4000 0000000000000000 [ 3.157364] 900000000101c998 0000000000000004 9000000000ef7430 0000000000000000 [ 3.167012] 0000000000000009 000000000000006c 0000000000000000 0000000000000000 [ 3.176641] 9000000000d3de08 9000000001639390 90000000002086d8 00007ffff0080286 [ 3.186260] 00000000000000b0 0000000000000004 0000000000000000 0000000000071c1c [ 3.195868] ... [ 3.199917] Call Trace: [ 3.203941] [<90000000002086d8>] showstack+0x38/0x14c [ 3.210666] [<9000000000cf846c>] dumpstacklvl+0x60/0x88 [ 3.217625] [<900000000023d268>] warn+0xd0/0x100 [ 3.223958] [<9000000000cf3c90>] warnslowpathfmt+0x7c/0xcc [ 3.231150] [<9000000000210220>] showcpuinfo+0x5e8/0x5f0 [ 3.238080] [<90000000004f578c>] seqreaditer+0x354/0x4b4 [ 3.245098] [<90000000004c2e90>] newsyncread+0x17c/0x1c4 [ 3.252114] [<90000000004c5174>] vfsread+0x138/0x1d0 [ 3.258694] [<90000000004c55f8>] ksysread+0x70/0x100 [ 3.265265] [<9000000000cfde9c>] dosyscall+0x7c/0x94 [ 3.271820] [<9000000000202fe4>] handlesyscall+0xc4/0x160 [ 3.281824] ---[ end trace 8b484262b4b8c24c ]---
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Adjust the cpuinfo/cpumask runtime warning path so cpu_max_bits_warn() iterates over CPUs using nr_cpu_ids rather than NR_CPUS; this is the fix described to prevent the CONFIG_CPUMASK_OFFSTACK + CONFIG_DEBUG_PER_CPU_MAPS show_cpuinfo warning.
Linux kernel (cpumask/cpuinfo) NR_CPUS iteration vs nr_cpu_ids = Use nr_cpu_ids instead of NR_CPUS for cpu iteration in cpu_max_bits_warn() runtime path
Event History
Frequently Asked Questions
What is the severity of CVE-2022-50223?
CVE-2022-50223 is considered a medium severity vulnerability in the Linux kernel.
How do I fix CVE-2022-50223?
To fix CVE-2022-50223, ensure you update your Linux kernel to the latest stable version that contains the patch for this vulnerability.
What are the potential impacts of CVE-2022-50223?
The potential impacts of CVE-2022-50223 include unnecessary runtime warnings that may affect system performance.
Which versions of Linux kernel are affected by CVE-2022-50223?
CVE-2022-50223 affects specific configurations in the Linux kernel but does not target a specific version range.
Is there a workaround for CVE-2022-50223?
While there is no official workaround for CVE-2022-50223, disabling CONFIG_CPUMASK_OFFSTACK may prevent the warning.