| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2024-56556: binder: fix node UAF in binder_add_freeze_work() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| binder: fix node UAF in binder_add_freeze_work() |
| |
| In binder_add_freeze_work() we iterate over the proc->nodes with the |
| proc->inner_lock held. However, this lock is temporarily dropped in |
| order to acquire the node->lock first (lock nesting order). This can |
| race with binder_node_release() and trigger a use-after-free: |
| |
| ================================================================== |
| BUG: KASAN: slab-use-after-free in _raw_spin_lock+0xe4/0x19c |
| Write of size 4 at addr ffff53c04c29dd04 by task freeze/640 |
| |
| CPU: 5 UID: 0 PID: 640 Comm: freeze Not tainted 6.11.0-07343-ga727812a8d45 #17 |
| Hardware name: linux,dummy-virt (DT) |
| Call trace: |
| _raw_spin_lock+0xe4/0x19c |
| binder_add_freeze_work+0x148/0x478 |
| binder_ioctl+0x1e70/0x25ac |
| __arm64_sys_ioctl+0x124/0x190 |
| |
| Allocated by task 637: |
| __kmalloc_cache_noprof+0x12c/0x27c |
| binder_new_node+0x50/0x700 |
| binder_transaction+0x35ac/0x6f74 |
| binder_thread_write+0xfb8/0x42a0 |
| binder_ioctl+0x18f0/0x25ac |
| __arm64_sys_ioctl+0x124/0x190 |
| |
| Freed by task 637: |
| kfree+0xf0/0x330 |
| binder_thread_read+0x1e88/0x3a68 |
| binder_ioctl+0x16d8/0x25ac |
| __arm64_sys_ioctl+0x124/0x190 |
| ================================================================== |
| |
| Fix the race by taking a temporary reference on the node before |
| releasing the proc->inner lock. This ensures the node remains alive |
| while in use. |
| |
| The Linux kernel CVE team has assigned CVE-2024-56556 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.12 with commit d579b04a52a183db47dfcb7a44304d7747d551e1 and fixed in 6.12.4 with commit 38fbefeb2c140b581ed7de8117a5c90d6dd89c22 |
| Issue introduced in 6.12 with commit d579b04a52a183db47dfcb7a44304d7747d551e1 and fixed in 6.13 with commit dc8aea47b928cc153b591b3558829ce42f685074 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2024-56556 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| drivers/android/binder.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/38fbefeb2c140b581ed7de8117a5c90d6dd89c22 |
| https://git.kernel.org/stable/c/dc8aea47b928cc153b591b3558829ce42f685074 |
