mmmremap.c: avoid pointless invalidate_range_start/end on mremap(old_size=0)
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 4 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-193 and the CVSS impact.
Summary
In the Linux kernel, the following vulnerability has been resolved: mmmremap.c: avoid pointless invalidate_range_start/end on mremap(old_size=0) If an mremap() syscall with old_size=0 ends up in move_page_tables(), it will call invalidate_range_start()/invalidate_range_end() unnecessarily, i.e. with an empty range. This causes a WARN in KVM's mmu_notifier. In the past, empty ranges have been diagnosed to be off-by-one bugs, hence the WARNing. Given the low (so far) number of unique reports, the benefits of detecting more buggy callers seem to outweigh the cost of having to fix cases such as this one, where userspace is doing something silly. In this particular case, an early return from move_page_tables() is enough to fix the issue.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 3.2 and later | 4.9.311, 4.14.276, 4.19.238, 5.4.189, 5.10.111, 5.15.34, 5.16.20, 5.17.3, 5.18 | Patch available | CNA |
- Linux VendorLinux Affected 3.2 and later Fixed in 4.9.311, 4.14.276, 4.19.238, 5.4.189, 5.10.111, 5.15.34, 5.16.20, 5.17.3, 5.18 Patch available CNA
CPE configurations NVD · 2
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | before 4.9.311; 4.10 to before 4.14.276; 4.15 to before 4.19.238; 4.20 to before 5.4.189; 5.5 to before 5.10.111; 5.11 to before 5.15.34; 5.16 to before 5.16.20; 5.17 to before 5.17.3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.18:rc1:*:*:*:*:*:* | 5.18 rc1 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 4.9.311; 4.10 to before 4.14.276; 4.15 to before 4.19.238; 4.20 to before 5.4.189; 5.5 to before 5.10.111; 5.11 to before 5.15.34; 5.16 to before 5.16.20; 5.17 to before 5.17.3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.18:rc1:*:*:*:*:*:* Versions 5.18 rc1 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 4.9.311, 4.14.276, 4.19.238, 5.4.189, 5.10.111, 5.15.34, 5.16.20, 5.17.3, 5.18
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 1 product
- Red Hat Enterprise Linux 10
Timeline
- 2026-10-02 Threatist record created from CVE-2022-49077
- 2026-10-03 Alias added: GHSA-qx25-m2gm-9qrc
- 2026-11-05 CISA SSVC decision points changed
References
Patch 9
- https://git.kernel.org/stable/c/a05540f3903bd8295e8c4cd90dd3d416239a115b
- https://git.kernel.org/stable/c/eeaf28e2a0128147d687237e59d5407ee1b14693
- https://git.kernel.org/stable/c/e2c328c2a8f9de8b761bd4025b66c63120c55761
- https://git.kernel.org/stable/c/c19d8de4e682ec4b0ea2b04a832cd8cc0be3bb31
- https://git.kernel.org/stable/c/7d659cb1763ff17d1c6ee082fa6feb4267c7a30b
- https://git.kernel.org/stable/c/a04cb99c5d4668fe3f5c0e5b6da1cecd34c3f219
- https://git.kernel.org/stable/c/2358aa84ef6dafcf544a557caaa6b91afb4a0bd2
- https://git.kernel.org/stable/c/04bc13dae4a27b8d030843c85ae452bb2f1d9c1f
- https://git.kernel.org/stable/c/01e67e04c28170c47700c2c226d732bbfedb1ad0
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- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2022-49077 · CVE Program
- CVE-2022-49077 · NVD
- FIRST EPSS
- GHSA-qx25-m2gm-9qrc · GitHub Advisory Database · CC BY 4.0
- CVE-2022-49077 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences