binder: fix freeze UAF in binder_release_work()

Summary

In the Linux kernel, the following vulnerability has been resolved: binder: fix freeze UAF in binder_release_work() When a binder reference is cleaned up, any freeze work queued in the associated process should also be removed. Otherwise, the reference is freed while its ref->freeze.work is still queued in proc->work leading to a use-after-free issue as shown by the following KASAN report: ================================================================== BUG: KASAN: slab-use-after-free in binder_release_work+0x398/0x3d0 Read of size 8 at addr ffff31600ee91488 by task kworker/5:1/211 CPU: 5 UID: 0 PID: 211 Comm: kworker/5:1 Not tainted 6.11.0-rc7-00382-gfc6c92196396 #22 Hardware name: linux,dummy-virt (DT) Workqueue: events binder_deferred_func Call trace: binder_release_work+0x398/0x3d0 binder_deferred_func+0xb60/0x109c process_one_work+0x51c/0xbd4 worker_thread+0x608/0xee8 Allocated by task 703: __kmalloc_cache_noprof+0x130/0x280 binder_thread_write+0xdb4/0x42a0 binder_ioctl+0x18f0/0x25ac __arm64_sys_ioctl+0x124/0x190 invoke_syscall+0x6c/0x254 Freed by task 211: kfree+0xc4/0x230 binder_deferred_func+0xae8/0x109c process_one_work+0x51c/0xbd4 worker_thread+0x608/0xee8 ================================================================== This commit fixes the issue by ensuring any queued freeze work is removed when cleaning up a binder reference.

Timeline

1. Dec 27, 2024, 2:22 PM UTCCVE published
2. Feb 10, 2025, 5:12 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: total

3. Aug 5, 2026, 11:45 AM UTCRecord last updated

Affected versions

• Linux Linux

  Version range not reported

• Linux Linux

  6.12

References 2