CVE-2026-72233 in Linux
Summary
by MITRE • 08/15/2026
In the Linux kernel, the following vulnerability has been resolved:
batman-adv: bla: reacquire gw address after skb realloc
The pskb_may_pull() called by batadv_bla_is_backbone_gw() 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.
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Analysis
by VulDB Data Team • 08/15/2026
The vulnerability in question affects the batman-adv kernel module, specifically within the bridge-less architecture component responsible for gateway management. This issue stems from improper handling of socket buffer memory reallocation during backbone gateway address validation operations. The flaw occurs when the pskb_may_pull() function is invoked by batadv_bla_is_backbone_gw(), which can trigger a buffer reallocation process that invalidates previously established pointers to packet data structures.
The technical root cause involves memory management practices where variables maintain references to specific memory locations within socket buffers that may be relocated during packet processing. When pskb_may_pull() executes and reallocates the underlying buffer, any pointers previously referencing the old memory location become stale, creating a use-after-free condition that can lead to system instability or potential privilege escalation. This type of vulnerability falls under CWE-416, specifically addressing Use After Free conditions in kernel space operations.
The operational impact of this vulnerability extends beyond simple system crashes to potentially enable malicious actors to exploit the memory corruption for privilege elevation within the kernel context. The batman-adv module operates at the network layer with elevated privileges, making any memory safety issues particularly dangerous as they could allow attackers to execute arbitrary code with kernel-level permissions. This vulnerability affects wireless mesh networks that utilize the batman-adv routing protocol, which is commonly deployed in enterprise and public wireless infrastructure.
Mitigation strategies should prioritize immediate kernel updates from trusted sources to address the specific buffer reallocation handling issue. System administrators should implement monitoring for unusual network behavior or kernel oops messages that may indicate memory corruption events. The fix requires reassigning pointer variables after pskb_may_pull() calls to ensure they reference the current buffer location rather than stale memory addresses. Security teams should also consider implementing network segmentation and access controls to limit potential attack vectors while patches are deployed, as recommended by the ATT&CK framework's privilege escalation tactics that target kernel vulnerabilities.