# CVE-2026-90307: RDMA/srp: fix heap information leak on a truncated SRP_CRED_REQ

> A malicious RDMA target can leak kernel heap memory to the initiator by sending truncated SRP requests, exposing sensitive data.

- **Severity:** Not scored
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 17 Sep 2026
- **Updated:** 19 Oct 2026
- **Also known as:** AZL-101903, BELL-CVE-2026-90307, DEBIAN-CVE-2026-90307, GHSA-24j7-gr38-qhjc, UBUNTU-CVE-2026-90307

## What is CVE-2026-90307?

CVE-2026-90307 is a vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

RDMA/srp: fix heap information leak on a truncated SRP_CRED_REQ

srp_recv_done() passes wc->byte_len to srp_process_rsp(). It passes
nothing to srp_process_cred_req() and srp_process_aer_req(), which read
fixed-size fields from the receive buffer without checking that those
fields were received.

The buffer size is max_ti_iu_len, which comes from the login response
and is not validated. A target that advertises 8 and then sends an
8-byte SRP_CRED_REQ makes the initiator read req->tag from beyond the
end of the buffer. req->tag is copied into the SRP_CRED_RSP and sent
back, so those bytes reach the target. SRP_AER_REQ behaves the same way
and also reads req->lun.

The leak is 8 bytes per response. max_ti_iu_len also decides which slab
cache the buffer comes from. With 8 the buffer is a kmalloc-8 object and
the read is entirely outside it:

  BUG: KASAN: slab-out-of-bounds in srp_recv_done+0x172b/0x1aa0
  Read of size 8 at addr ffff888104714da8 by task kworker/u8:3/50
   which belongs to the cache kmalloc-8 of size 8
  The buggy address is located 0 bytes to the right of
   allocated 8-byte region [ffff888104714da0, ffff888104714da8)

Without KASAN the returned bytes are whatever is next in the slab. One
run returned ".strtab".

rsp->data[3] in srp_process_rsp() has the same problem: only
resp_data_len is checked before it is read.

Drop a request that is shorter than the structure being parsed, and
check byte_len before the tsk_mgmt read.

## Which versions are affected by CVE-2026-90307?


## How do I fix CVE-2026-90307?

Apply the vendor's patch.

## Is CVE-2026-90307 being exploited?

There is no known exploitation of CVE-2026-90307 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-90307 and fix it if it is affected.

What it is: CVE-2026-90307 is a vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-90307 in the wild and no public exploit code.

Affected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-90307/ (Markdown: https://insights.sbomify.com/CVE-2026-90307/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-90307
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-90307
- OSV: https://osv.dev/vulnerability/CVE-2026-90307

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-90307/
Summaries are generated and may contain mistakes; the official description above is the record.