rxrpc: Fix bug due to prealloc collision
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: 2 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-617.
Summary
In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix bug due to prealloc collision When userspace is using AF_RXRPC to provide a server, it has to preallocate incoming calls and assign to them call IDs that will be used to thread related recvmsg() and sendmsg() together. The preallocated call IDs will automatically be attached to calls as they come in until the pool is empty. To the kernel, the call IDs are just arbitrary numbers, but userspace can use the call ID to hold a pointer to prepared structs. In any case, the user isn't permitted to create two calls with the same call ID (call IDs become available again when the call ends) and EBADSLT should result from sendmsg() if an attempt is made to preallocate a call with an in-use call ID. However, the cleanup in the error handling will trigger both assertions in rxrpc_cleanup_call() because the call isn't marked complete and isn't marked as having been released. Fix this by setting the call state in rxrpc_service_prealloc_one() and then marking it as being released before calling the cleanup function.
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 | 4.9 and later | 6.1.191, 6.6.99, 6.12.39, 6.15.7, 6.16 | Patch available | CNA |
- Linux VendorLinux Affected 4.9 and later Fixed in 6.1.191, 6.6.99, 6.12.39, 6.15.7, 6.16 Patch available CNA
CPE configurations NVD · 6
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 4.9 to before 6.6.99; 6.7 to before 6.12.39; 6.13 to before 6.15.7 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.16:rc1:*:*:*:*:*:* | 6.16 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.16:rc2:*:*:*:*:*:* | 6.16 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.16:rc3:*:*:*:*:*:* | 6.16 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.16:rc4:*:*:*:*:*:* | 6.16 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.16:rc5:*:*:*:*:*:* | 6.16 rc5 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.9 to before 6.6.99; 6.7 to before 6.12.39; 6.13 to before 6.15.7 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.16:rc1:*:*:*:*:*:* Versions 6.16 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.16:rc2:*:*:*:*:*:* Versions 6.16 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.16:rc3:*:*:*:*:*:* Versions 6.16 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.16:rc4:*:*:*:*:*:* Versions 6.16 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.16:rc5:*:*:*:*:*:* Versions 6.16 rc5 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.1.191, 6.6.99, 6.12.39, 6.15.7, 6.16
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
Not affected: 3 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
Timeline
- 2026-10-02 Threatist record created from CVE-2025-38544
- 2026-10-03 Alias added: GHSA-2fgf-j87m-qgrf
- 2026-10-30 Fix available: Linux/Linux@3838acfc347b803b66a2c8eb510da1c489d44ca1, Linux/[email protected] · CNA
- 2026-10-30 1 new reference · CNA
- 2026-11-05 CISA SSVC decision points changed
References
Patch 4
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- 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-2025-38544 · CVE Program
- CVE-2025-38544 · NVD
- FIRST EPSS
- GHSA-2fgf-j87m-qgrf · GitHub Advisory Database · CC BY 4.0
- CVE-2025-38544 · 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