CVE-2021-47261
IB/mlx5: Fix initializing CQ fragments buffer
- Published
- Updated
- Reserved
- Assigned by
- Linux
Description
In the Linux kernel, the following vulnerability has been resolved: IB/mlx5: Fix initializing CQ fragments buffer The function init_cq_frag_buf() can be called to initialize the current CQ fragments buffer cq->buf, or the temporary cq->resize_buf that is filled during CQ resize operation. However, the offending commit started to use function get_cqe() for getting the CQEs, the issue with this change is that get_cqe() always returns CQEs from cq->buf, which leads us to initialize the wrong buffer, and in case of enlarging the CQ we try to access elements beyond the size of the current cq->buf and eventually hit a kernel panic. [exception RIP: init_cq_frag_buf+103] [ffff9f799ddcbcd8] mlx5_ib_resize_cq at ffffffffc0835d60 [mlx5_ib] [ffff9f799ddcbdb0] ib_resize_cq at ffffffffc05270df [ib_core] [ffff9f799ddcbdc0] llt_rdma_setup_qp at ffffffffc0a6a712 [llt] [ffff9f799ddcbe10] llt_rdma_cc_event_action at ffffffffc0a6b411 [llt] [ffff9f799ddcbe98] llt_rdma_client_conn_thread at ffffffffc0a6bb75 [llt] [ffff9f799ddcbec8] kthread at ffffffffa66c5da1 [ffff9f799ddcbf50] ret_from_fork_nospec_begin at ffffffffa6d95ddd Fix it by getting the needed CQE by calling mlx5_frag_buf_get_wqe() that takes the correct source buffer as a parameter.
Timeline
ID reserved
By Linux
Published
- 2 years later
· 2 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.24% · top 85% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Weakness
Affected products
- affected 388ca8be00370db132464e27f745b8a0add19fcb – < 1ec2dcd680c71d0d36fa25638b327a468babd5c9
- affected 388ca8be00370db132464e27f745b8a0add19fcb – < e3ecd9c09fcc10cf6b2bc67e2990c397c40a8c26
- affected 388ca8be00370db132464e27f745b8a0add19fcb – < 91f7fdc4cc10542ca1045c06aad23365f0d067e0
- affected 388ca8be00370db132464e27f745b8a0add19fcb – < 3e670c54eda238cb8a1ea93538a79ae89285c1c4
- affected 388ca8be00370db132464e27f745b8a0add19fcb – < 2ba0aa2feebda680ecfc3c552e867cf4d1b05a3a
- affected 4.17
- unaffected < 4.17
- unaffected 4.19.195 – ≤ 4.19.*
- unaffected 5.4.126 – ≤ 5.4.*
- unaffected 5.10.44 – ≤ 5.10.*
- unaffected 5.12.11 – ≤ 5.12.*
- unaffected 5.13 – ≤ *
References (5)
- https://git.kernel.org/stable/c/1ec2dcd680c71d0d36fa25638b327a468babd5c9 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/e3ecd9c09fcc10cf6b2bc67e2990c397c40a8c26 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/91f7fdc4cc10542ca1045c06aad23365f0d067e0 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/3e670c54eda238cb8a1ea93538a79ae89285c1c4 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/2ba0aa2feebda680ecfc3c552e867cf4d1b05a3a (opens in a new tab)x_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2021-47261)Record last updated .