# CVE-2025-71096: RDMA/core: Check for the presence of LS_NLA_TYPE_DGID correctly

> A local attacker can trigger an uninitialized memory read in the Linux kernel RDMA subsystem, potentially leaking sensitive kernel stack data.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 Jan 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2025-71096, DEBIAN-CVE-2025-71096, GHSA-vxx9-9gjr-jrj2, ROOT-OS-UBUNTU-2204-CVE-2025-71096, ROOT-OS-UBUNTU-2404-CVE-2025-71096, UBUNTU-CVE-2025-71096

## What is CVE-2025-71096?

CVE-2025-71096 is a medium-severity vulnerability in Linux kernel, published on 13 Jan 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/core: Check for the presence of LS_NLA_TYPE_DGID correctly

The netlink response for RDMA_NL_LS_OP_IP_RESOLVE should always have a
LS_NLA_TYPE_DGID attribute, it is invalid if it does not.

Use the nl parsing logic properly and call nla_parse_deprecated() to fill
the nlattrs array and then directly index that array to get the data for
the DGID. Just fail if it is NULL.

Remove the for loop searching for the nla, and squash the validation and
parsing into one function.

Fixes an uninitialized read from the stack triggered by userspace if it
does not provide the DGID to a kernel initiated RDMA_NL_LS_OP_IP_RESOLVE
query.

    BUG: KMSAN: uninit-value in hex_byte_pack include/linux/hex.h:13 [inline]
    BUG: KMSAN: uninit-value in ip6_string+0xef4/0x13a0 lib/vsprintf.c:1490
     hex_byte_pack include/linux/hex.h:13 [inline]
     ip6_string+0xef4/0x13a0 lib/vsprintf.c:1490
     ip6_addr_string+0x18a/0x3e0 lib/vsprintf.c:1509
     ip_addr_string+0x245/0xee0 lib/vsprintf.c:1633
     pointer+0xc09/0x1bd0 lib/vsprintf.c:2542
     vsnprintf+0xf8a/0x1bd0 lib/vsprintf.c:2930
     vprintk_store+0x3ae/0x1530 kernel/printk/printk.c:2279
     vprintk_emit+0x307/0xcd0 kernel/printk/printk.c:2426
     vprintk_default+0x3f/0x50 kernel/printk/printk.c:2465
     vprintk+0x36/0x50 kernel/printk/printk_safe.c:82
     _printk+0x17e/0x1b0 kernel/printk/printk.c:2475
     ib_nl_process_good_ip_rsep drivers/infiniband/core/addr.c:128 [inline]
     ib_nl_handle_ip_res_resp+0x963/0x9d0 drivers/infiniband/core/addr.c:141
     rdma_nl_rcv_msg drivers/infiniband/core/netlink.c:-1 [inline]
     rdma_nl_rcv_skb drivers/infiniband/core/netlink.c:239 [inline]
     rdma_nl_rcv+0xefa/0x11c0 drivers/infiniband/core/netlink.c:259
     netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
     netlink_unicast+0xf04/0x12b0 net/netlink/af_netlink.c:1346
     netlink_sendmsg+0x10b3/0x1250 net/netlink/af_netlink.c:1896
     sock_sendmsg_nosec net/socket.c:714 [inline]
     __sock_sendmsg+0x333/0x3d0 net/socket.c:729
     ____sys_sendmsg+0x7e0/0xd80 net/socket.c:2617
     ___sys_sendmsg+0x271/0x3b0 net/socket.c:2671
     __sys_sendmsg+0x1aa/0x300 net/socket.c:2703
     __compat_sys_sendmsg net/compat.c:346 [inline]
     __do_compat_sys_sendmsg net/compat.c:353 [inline]
     __se_compat_sys_sendmsg net/compat.c:350 [inline]
     __ia32_compat_sys_sendmsg+0xa4/0x100 net/compat.c:350
     ia32_sys_call+0x3f6c/0x4310 arch/x86/include/generated/asm/syscalls_32.h:371
     do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
     __do_fast_syscall_32+0xb0/0x150 arch/x86/entry/syscall_32.c:306
     do_fast_syscall_32+0x38/0x80 arch/x86/entry/syscall_32.c:331
     do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:3

Weakness: CWE-908 (Use of Uninitialized Resource), CWE-457 (Use of Uninitialized Variable)

## Which versions are affected by CVE-2025-71096?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-71096?

Apply the vendor's patch.

## Is CVE-2025-71096 being exploited?

There is no known exploitation of CVE-2025-71096 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-71096 and fix it if it is affected.

What it is: CVE-2025-71096 is a medium-severity vulnerability in Linux kernel, published on 13 Jan 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-2025-71096 in the wild and no public exploit code.

Affected product: Linux kernel. 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-2025-71096/ (Markdown: https://insights.sbomify.com/CVE-2025-71096/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-71096
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-71096
- OSV: https://osv.dev/vulnerability/CVE-2025-71096

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-71096/
Summaries are generated and may contain mistakes; the official description above is the record.
