Bug 2516597 (CVE-2026-72234)

Summary: CVE-2026-72234 kernel: batman-adv: access unicast_ttvn skb->data only after skb realloc
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's batman-adv module. When the `pskb_may_pull()` function is called by `batadv_get_vid()`, it can reallocate a buffer. However, a pointer to the old buffer, specifically `unicast_packet`, was not correctly reassigned, leading to a use-after-free condition. This memory corruption vulnerability could allow a local attacker to cause a denial of service or potentially escalate privileges.
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Description OSIDB Bzimport 2026-08-15 06:21:03 UTC 
In the Linux kernel, the following vulnerability has been resolved:

batman-adv: access unicast_ttvn skb->data only after skb realloc

The pskb_may_pull() called by batadv_get_vid() could reallocate the buffer
behind the skb. Variables which were pointing to the old buffer need to be
reassigned to avoid an use-after-free.

This was done correctly for the ethernet header but missed for the
unicast_packet pointer.
Comment 1 Keith Grant 2026-08-18 16:53:18 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081550-CVE-2026-72234-598a@gregkh/T