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CVE-2026-64469VulnerabilityPublished 07/25/2026

In the Linux kernel, the following vulnerability has been resolved: binder: fix UAF in binder_thread_release() When a thread exits,… (CVE-2026-64469)

Source GCVE Database

0
Severity
High

No CVSS score published yet

Exploitation

Not in CISA KEV, no exploitation reported

EPSS
0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

What to do

AI-suggested

A fix has been implemented in the Linux kernel to address this vulnerability by properly synchronizing access to transaction structures with locking. Users should apply the official kernel updates that include this fix. Patch status is not explicitly confirmed in the provided data; therefore, check the vendor or Linux kernel advisories for the current remediation guidance.

Description

In the Linux kernel, the following vulnerability has been resolved: binder: fix UAF in binder_thread_release() When a thread exits, binder_thread_release() walks its transaction stack to clear the t->from and t->to_proc that correspond with the exiting thread. However, a process dying in parallel might attempt to kfree some of these transactions. And if one of them has no associated t->to_proc, the t->to_proc->inner_lock will not be acquired. This means that transaction accesses in binder_thread_release() after t->to_proc has been cleared might race with binder_free_transaction() and cause a use-after-free error as reported by KASAN: ================================================================== BUG: KASAN: slab-use-after-free in binder_thread_release+0x5d0/0x798 Write of size 8 at addr ffff000016627500 by task X/715 CPU: 17 UID: 0 PID: 715 Comm: X Not tainted 7.1.0-rc5-00149-g8fde5d1d47f6 #30 PREEMPT Hardware name: linux,dummy-virt (DT) Call trace: binder_thread_release+0x5d0/0x798 binder_ioctl+0x12c0/0x299c [...] Allocated by task 717 on cpu 18 at 67.267803s: __kasan_kmalloc+0xa0/0xbc __kmalloc_cache_noprof+0x174/0x444 binder_transaction+0x554/0x8150 binder_thread_write+0xa30/0x4354 binder_ioctl+0x20f0/0x299c [...] Freed by task 202 on cpu 18 at 90.416221s: __kasan_slab_free+0x58/0x80 kfree+0x1a0/0x4a4 binder_free_transaction+0x150/0x294 binder_send_failed_reply+0x398/0x6d8 binder_release_work+0x3e4/0x4ec binder_deferred_func+0xbd8/0x104c [...] ================================================================== In order to avoid this, make sure that binder_free_transaction() reads the t->to_proc under the transaction lock. This will serialize the transaction release with the accesses in binder_thread_release(). Plus, it matches the documented locking rules for @to_proc.

Impact

This vulnerability can lead to use-after-free conditions in kernel memory, potentially causing kernel crashes or memory corruption. There is no indication of known exploits in the wild. The impact is limited to kernel stability and security but does not specify privilege escalation or remote code execution.

Summary

The Linux kernel binder driver contained a use-after-free vulnerability in binder_thread_release(). When a thread exits, the function clears transaction references, but if a process dies concurrently, binder_free_transaction() may free transactions without acquiring the necessary locks if t->to_proc is NULL. This race condition allows binder_thread_release() to access freed memory, causing a use-after-free error. The fix ensures binder_free_transaction() reads t->to_proc under the transaction lock, serializing transaction release and access, and aligning with documented locking rules.

References

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