CVE-2026-31657
batman-adv: hold claim backbone gateways by reference
Description
In the Linux kernel, the following vulnerability has been resolved: batman-adv: hold claim backbone gateways by reference batadv_bla_add_claim() can replace claim->backbone_gw and drop the old gateway's last reference while readers still follow the pointer. The netlink claim dump path dereferences claim->backbone_gw->orig and takes claim->backbone_gw->crc_lock without pinning the underlying backbone gateway. batadv_bla_check_claim() still has the same naked pointer access pattern. Reuse batadv_bla_claim_get_backbone_gw() in both readers so they operate on a stable gateway reference until the read-side work is complete. This keeps the dump and claim-check paths aligned with the lifetime rules introduced for the other BLA claim readers.
INFO
Published Date :
April 24, 2026, 3:16 p.m.
Last Modified :
April 24, 2026, 3:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-31657
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Apply kernel patch.
- Reuse batadv_bla_claim_get_backbone_gw() function.
- Pin the underlying backbone gateway.
- Ensure stable gateway references.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-31657.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-31657 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-31657
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-31657 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-31657 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Apr. 24, 2026
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: batman-adv: hold claim backbone gateways by reference batadv_bla_add_claim() can replace claim->backbone_gw and drop the old gateway's last reference while readers still follow the pointer. The netlink claim dump path dereferences claim->backbone_gw->orig and takes claim->backbone_gw->crc_lock without pinning the underlying backbone gateway. batadv_bla_check_claim() still has the same naked pointer access pattern. Reuse batadv_bla_claim_get_backbone_gw() in both readers so they operate on a stable gateway reference until the read-side work is complete. This keeps the dump and claim-check paths aligned with the lifetime rules introduced for the other BLA claim readers. Added Reference https://git.kernel.org/stable/c/1f2dc36c297d27733f1b380ea644cf15a361bd7b Added Reference https://git.kernel.org/stable/c/2f55b58b5a0bbed192d60c444a45a49cdf1b545f Added Reference https://git.kernel.org/stable/c/4dee4c0688443aaf5bbec74aa203c851d1d53c35 Added Reference https://git.kernel.org/stable/c/7962b522222628596ca9ecc8722efc95367aadbd Added Reference https://git.kernel.org/stable/c/82d8701b2c930d0e96b0dbc9115a218d791cb0d2 Added Reference https://git.kernel.org/stable/c/f4858832ddef2f39f21e30b7226bbcd3c4b2bc96