CVE-2021-47482
net: batman-adv: fix error handling
- Published
- Updated
- Reserved
- Assigned by
- Linux
Description
In the Linux kernel, the following vulnerability has been resolved: net: batman-adv: fix error handling Syzbot reported ODEBUG warning in batadv_nc_mesh_free(). The problem was in wrong error handling in batadv_mesh_init(). Before this patch batadv_mesh_init() was calling batadv_mesh_free() in case of any batadv_*_init() calls failure. This approach may work well, when there is some kind of indicator, which can tell which parts of batadv are initialized; but there isn't any. All written above lead to cleaning up uninitialized fields. Even if we hide ODEBUG warning by initializing bat_priv->nc.work, syzbot was able to hit GPF in batadv_nc_purge_paths(), because hash pointer in still NULL. [1] To fix these bugs we can unwind batadv_*_init() calls one by one. It is good approach for 2 reasons: 1) It fixes bugs on error handling path 2) It improves the performance, since we won't call unneeded batadv_*_free() functions. So, this patch makes all batadv_*_init() clean up all allocated memory before returning with an error to no call correspoing batadv_*_free() and open-codes batadv_mesh_free() with proper order to avoid touching uninitialized fields.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Analyzed | 3.1 | Medium5.3 | CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.74% · top 45% of all CVEs (6 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: Medium 5.3.
Weakness
Affected products
- affected c6c8fea29769d998d94fcec9b9f14d4b52b349d3 – < 0c6b199f09be489c48622537a550787fc80aea73
- affected c6c8fea29769d998d94fcec9b9f14d4b52b349d3 – < 07533f1a673ce1126d0a72ef1e4b5eaaa3dd6d20
- affected c6c8fea29769d998d94fcec9b9f14d4b52b349d3 – < e50f957652190b5a88a8ebce7e5ab14ebd0d3f00
- affected c6c8fea29769d998d94fcec9b9f14d4b52b349d3 – < fbf150b16a3635634b7dfb7f229d8fcd643c6c51
- affected c6c8fea29769d998d94fcec9b9f14d4b52b349d3 – < 6422e8471890273994fe8cc6d452b0dcd2c9483e
- affected c6c8fea29769d998d94fcec9b9f14d4b52b349d3 – < b0a2cd38553c77928ef1646ed1518486b1e70ae8
- affected c6c8fea29769d998d94fcec9b9f14d4b52b349d3 – < a8f7359259dd5923adc6129284fdad12fc5db347
- affected c6c8fea29769d998d94fcec9b9f14d4b52b349d3 – < 6f68cd634856f8ca93bafd623ba5357e0f648c68
- affected 2.6.38
- unaffected < 2.6.38
- unaffected 4.4.293 – ≤ 4.4.*
- unaffected 4.9.289 – ≤ 4.9.*
- unaffected 4.14.254 – ≤ 4.14.*
- unaffected 4.19.215 – ≤ 4.19.*
- unaffected 5.4.157 – ≤ 5.4.*
- unaffected 5.10.77 – ≤ 5.10.*
- unaffected 5.14.16 – ≤ 5.14.*
- unaffected 5.15 – ≤ *
References (8)
- https://git.kernel.org/stable/c/0c6b199f09be489c48622537a550787fc80aea73 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/07533f1a673ce1126d0a72ef1e4b5eaaa3dd6d20 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/e50f957652190b5a88a8ebce7e5ab14ebd0d3f00 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/fbf150b16a3635634b7dfb7f229d8fcd643c6c51 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/6422e8471890273994fe8cc6d452b0dcd2c9483e (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/b0a2cd38553c77928ef1646ed1518486b1e70ae8 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/a8f7359259dd5923adc6129284fdad12fc5db347 (opens in a new tab)x_transferred
- https://git.kernel.org/stable/c/6f68cd634856f8ca93bafd623ba5357e0f648c68 (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-2021-47482)Record last updated .