CVE-2022-49675

MEDIUMCVSS 5.5/10EPSS 0.27%

Last modified

CVE-2022-49675 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: tick/nohz: unexport __init-annotated tick_nohz_full_setup() EXPORT_SYMBOL and __init is a bad combination because the .init.text section is freed up after the initialization. Hence, modules cannot use symbols annotated __init. EPSS estimates a 0.27% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: tick/nohz: unexport __init-annotated tick_nohz_full_setup() EXPORT_SYMBOL and __init is a bad combination because the .init.text section is freed up after the initialization. Hence, modules cannot use symbols annotated __init. The access to a freed symbol may end up with kernel panic. modpost used to detect it, but it had been broken for a decade. Commit 28438794aba4 ("modpost: fix section mismatch check for exported init/exit sections") fixed it so modpost started to warn it again, then this showed up: MODPOST vmlinux.symvers WARNING: modpost: vmlinux.o(___ksymtab_gpl+tick_nohz_full_setup+0x0): Section mismatch in reference from the variable __ksymtab_tick_nohz_full_setup to the function .init.text:tick_nohz_full_setup() The symbol tick_nohz_full_setup is exported and annotated __init Fix this by removing the __init annotation of tick_nohz_full_setup or drop the export. Drop the export because tick_nohz_full_setup() is only called from the built-in code in kernel/sched/isolation.c.

Metrics

CVSS 3.1
5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability
0.27%

18.2th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
LinuxLinux Kernel>= 5.5, < 5.10.128
LinuxLinux Kernel>= 5.11, < 5.15.52
LinuxLinux Kernel>= 5.16, < 5.18.9
LinuxLinux Kernel5.19Rc1

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2022-49675?
In the Linux kernel, the following vulnerability has been resolved: tick/nohz: unexport __init-annotated tick_nohz_full_setup() EXPORT_SYMBOL and __init is a bad combination because the .init.text section is freed up after the initialization. Hence, modules cannot use symbols annotated __init. The access to a freed symbol may end up with kernel panic. modpost used to detect it, but it had been broken for a decade. Commit 28438794aba4 ("modpost: fix section mismatch check for exported init/exit sections") fixed it so modpost started to warn it again, then this showed up: MODPOST vmlinux.symvers WARNING: modpost: vmlinux.o(___ksymtab_gpl+tick_nohz_full_setup+0x0): Section mismatch in reference from the variable __ksymtab_tick_nohz_full_setup to the function .init.text:tick_nohz_full_setup() The symbol tick_nohz_full_setup is exported and annotated __init Fix this by removing the __init annotation of tick_nohz_full_setup or drop the export. Drop the export because tick_nohz_full_setup() is only called from the built-in code in kernel/sched/isolation.c.
How severe is CVE-2022-49675?
CVE-2022-49675 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.27% probability of exploitation in the next 30 days.
How do I fix CVE-2022-49675?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2022-49675?

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Source: NVD / NIST