Bug 2454876 (CVE-2026-23444)

Summary: CVE-2026-23444 kernel: wifi: mac80211: always free skb on ieee80211_tx_prepare_skb() failure
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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Doc Text:
A flaw was found in the Linux kernel's mac80211 Wi-Fi subsystem. This vulnerability occurs because a specific error path within the `ieee80211_tx_prepare_skb()` function fails to properly release a network buffer, known as a socket buffer (skb). This inconsistency can lead to a double-free condition, where the same memory is freed multiple times. A local attacker could exploit this to cause memory corruption, potentially leading to a system crash (Denial of Service) or, in more severe scenarios, the execution of unauthorized code.
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Description OSIDB Bzimport 2026-04-03 16:05:42 UTC 
In the Linux kernel, the following vulnerability has been resolved:

wifi: mac80211: always free skb on ieee80211_tx_prepare_skb() failure

ieee80211_tx_prepare_skb() has three error paths, but only two of them
free the skb. The first error path (ieee80211_tx_prepare() returning
TX_DROP) does not free it, while invoke_tx_handlers() failure and the
fragmentation check both do.

Add kfree_skb() to the first error path so all three are consistent,
and remove the now-redundant frees in callers (ath9k, mt76,
mac80211_hwsim) to avoid double-free.

Document the skb ownership guarantee in the function's kdoc.
Comment 1 Jon Moroney 2026-04-03 16:26:14 UTC Comment hidden (spam)