CVE-2022-49990 — s390: fix double free of GS and RI CBs on fork() failure
In the Linux kernel, the following vulnerability has been resolved: s390: fix double free of GS and RI CBs on fork() failure The pointers for guarded storage and runtime instrumentation control blocks are stored in the thread_struct of the associated task. These pointers are initially copied on fork() via arch_dup_task_struct() and then cleared via copy_thread() before fork() returns. If fork() happens to fail after the initial task dup and before copy_thread(), the newly allocated task and associated thread_struct memory are freed via free_task() -> arch_release_task_struct(). This results in a double free of the guarded storage and runtime info structs because the fields in the failed task still refer to memory associated with the source task. This problem can manifest as a BUG_ON() in set_freepointer() (with CONFIG_SLAB_FREELIST_HARDENED enabled) or KASAN splat (if enabled) when running trinity syscall fuzz tests on s390x. To avoid this problem, clear the associated pointer fields in arch_dup_task_struct() immediately after the new task is copied. Note that the RI flag is still cleared in copy_thread() because it resides in thread stack memory and that is where stack info is copied.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.3% (30-day exploitation probability)+2
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
- Documented patch — git.kernel.org (NIST National Vulnerability Database)
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux, Linux Linux Kernel).
- Apply the fixed version or the patch documented under Remediation.
- Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux |
≥ 8d9047f8b967ce6181fd824ae922978e1b055cc0 and < 297ae7e87a87a001dd3dfeac1cb26a42fd929708version 4.15≥ 4.14.5 and < 4.15≥ 4.9.68 and < 4.10≥ 4.4.105 and < 4.5version b8e212c599082896a180a18a0c9bd529526590beversion 232b47b3c88af1da737cd7760f247c4ed58168cfversion 9e51ee1b76efc7b5e9404010793a39fde0e03cb7 and 5 more≥ 8d9047f8b967ce6181fd824ae922978e1b055cc0 and < 13cccafe0edcd03bf1c841de8ab8a1c8e34f77d9≥ 8d9047f8b967ce6181fd824ae922978e1b055cc0 and < fbdc482d43eda40a70de4b0155843d5472f6de62≥ 8d9047f8b967ce6181fd824ae922978e1b055cc0 and < 8195e065abf3df84eb0ad2987e76a40f21d1791c≥ 8d9047f8b967ce6181fd824ae922978e1b055cc0 and < cacd522e6652fbc2dc0cc6ae11c4e30782fef14b≥ 8d9047f8b967ce6181fd824ae922978e1b055cc0 and < 25a95303b9e513cd2978aacc385d06e6fec23d07 |
Vulnerable | CVE Program (cve.org) e CISA ADP |
| Linux | Linux Kernel |
≥ 4.4.105 and < 4.5version 6.0-rc2version 6.0-rc1≥ 5.16 and < 5.19.6≥ 5.11 and < 5.15.64≥ 5.5 and < 5.10.140≥ 4.20 and < 5.4.212≥ 4.14.5 and < 4.19.257 and 1 more≥ 4.9.68 and < 4.10 |
Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | 1.8 | 5.9 | nvd@nist.gov via NIST National Vulnerability Database |
| 7.8 | CVSS 3.1 | High | — | — | GitHub, Inc. via GitHub Security Advisories |
| 7.8 | CVSS 3.1 | High | — | — | Linux via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Local/physical vector: focus on endpoint telemetry (EDR) from affected hosts.
- Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · linux/linux
- SSVC assessment updated
- Record published
- Fix documented
- Affected products added · linux/linux kernel
- CVSS changed · 7.8
- Source status changed · → Modified
- Record created in this database
- 2025
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 2× References added · Oct 15, 2026 – Oct 15, 2026
- 1× Official description updated · Oct 15, 2026 – Oct 15, 2026
References
8 on the record
- git.kernel.org/stable/c/25a95303b9e513cd2978aacc385d06e6fec23d07
- git.kernel.org/stable/c/fbdc482d43eda40a70de4b0155843d5472f6de62
- git.kernel.org/stable/c/13cccafe0edcd03bf1c841de8ab8a1c8e34f77d9
- git.kernel.org/stable/c/297ae7e87a87a001dd3dfeac1cb26a42fd929708
- git.kernel.org/stable/c/8195e065abf3df84eb0ad2987e76a40f21d1791c
- git.kernel.org/stable/c/cacd522e6652fbc2dc0cc6ae11c4e30782fef14b
- nvd.nist.gov/vuln/detail/CVE-2022-49990
- github.com/advisories/GHSA-8px8-fjv5-9vgx
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 12h
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 12h
- Unknown CVE-2026-98430 RDMA/efa: Keep admin queues alive while IRQ is registered 1d
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 1d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 1d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 1d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2022-49990 is "s390: fix double free of GS and RI CBs on fork() failure", rated High. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 7.8 describes technical severity. EPSS 0.26% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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