GHSA-c7cr-ch33-3xr3 · 深刻度： high — In the Linux kernel, the following vulnerability has been resolved: wifi: brcmfmac: fix use...
In the Linux kernel, the following vulnerability has been resolved: wifi: brcmfmac: fix use-after-free when rescheduling brcmf_btcoex_info work The brcmf_btcoex_detach() only shuts down the btcoex timer, if the flag timer_on is false. However, the brcmf_btcoex_timerfunc(), which runs as timer handler, sets timer_on to false. This creates critical race conditions: 1.If brcmf_btcoex_detach() is called while brcmf_btcoex_timerfunc() is executing, it may observe timer_on as false and skip the call to timer_shutdown_sync(). 2.The brcmf_btcoex_timerfunc() may then reschedule the brcmf_btcoex_info worker after the cancel_work_sync() has been executed, resulting in use-after-free bugs. The use-after-free bugs occur in two distinct scenarios, depending on the timing of when the brcmf_btcoex_info struct is freed relative to the execution of its worker thread. Scenario 1: Freed before the worker is scheduled The brcmf_btcoex_info is deallocated before the worker is scheduled. A race condition can occur when schedule_work(&bt_local->work) is called after the target memory has been freed. The sequence of events is detailed below: CPU0 | CPU1 brcmf_btcoex_detach | brcmf_btcoex_timerfunc | bt_local->timer_on = false; if (cfg->btcoex->timer_on) | ... | cancel_work_sync(); | ... | kfree(cfg->btcoex); // FREE | | schedule_work(&bt_local->work); // USE Scenario 2: Freed after the worker is scheduled The brcmf_btcoex_info is freed after the worker has been scheduled but before or during its execution. In this case, statements within the brcmf_btcoex_handler() — such as the container_of macro and subsequent dereferences of the brcmf_btcoex_info object will cause a use-after-free access. The following timeline illustrates this scenario: CPU0 | CPU1 brcmf_btcoex_detach | brcmf_btcoex_timerfunc | bt_local->timer_on = false; if (cfg->btcoex->timer_on) | ... | cancel_work_sync(); | ... | schedule_work(); // Reschedule | kfree(cfg->btcoex); // FREE | brcmf_btcoex_handler() // Worker /* | btci = container_of(....); // USE The kfree() above could | ... also occur at any point | btci-> // USE during the worker's execution| */ | To resolve the race conditions, drop the conditional check and call timer_shutdown_sync() directly. It can deactivate the timer reliably, regardless of its current state. Once stopped, the timer_on state is then set to false.
総合評価: CVE-2025-39863 は低リスク（32.8/100）。CVSS 深刻度は高。悪用される可能性が高い（EPSS 0.15%、4 パーセンタイル） 推奨対応: 悪用情報と EPSS の推移を監視し、必要に応じて優先度を見直してください。
リスクは変動します。再評価に基づき、本ページの表示内容を更新しています。
EPSS は日次で悪用されやすさの相対度合いを推定します。パーセンタイルは採点済み CVE の中での相対位置（高いほど相対的に深刻）を示します。
| # | 日付 | 旧 EPSS スコア | 新 EPSS スコア | Δ（新 − 旧） |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.02% | 0.15% | +0.13% |
| 2 | 2025-09-20 | — | 0.02% | — |
EPSS の全履歴 （全 2 件）
この CVE の CVSS 指標。
| ベーススコア | バージョン | 深刻度 | ベクトル | 悪用しやすさ | 影響 | スコアの出典 |
|---|---|---|---|---|---|---|
| 7.8 | 3.1 | HIGH |
|
1.8 | 5.9 | [email protected] |
| 7.8 | 3.1 | HIGH |
|
1.8 | 5.9 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
GHSA-c7cr-ch33-3xr3 · 深刻度： high — In the Linux kernel, the following vulnerability has been resolved: wifi: brcmfmac: fix use...
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2025-39863 not yet assigned priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5, open 1. | https://security-tracker.debian.org/tracker/CVE-2025-39863 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2025-39863 |
suse
|
medium | CVE-2025-39863 severity moderate: SUSE including 471 source package names (2.1.3-6.80:kernel-default-base-6.4.0-35.1.21.12, 2.1.3-7.57:kernel-default-6.4.0-35.1, …), 954 product×package rows across 197 product lines (Container suse/sl-micro/6.0/base-os-container, Container suse/sl-micro/6.0/kvm-os-container, … (197 product lines)): Fixed 696, Known Affected 231, First Fixed 21, Known Not Affected 6. | https://www.suse.com/security/cve/CVE-2025-39863/ |
ubuntu
|
medium | CVE-2025-39863 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1414 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 1017, ignored 180, released 117, needed 79, not-affected 17, needs-triage 2, pending 2. | https://ubuntu.com/security/CVE-2025-39863 |
| ベンダー | 製品 | バージョン | 生の CPE |
|---|---|---|---|
| linux | linux_kernel | >= 3.10, < 5.15.210 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 3.10, < 6.1.167 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 3.10, < 6.6.105 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 3.10, < 6.12.46 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 3.10, < 6.16.6 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 3.10, < 6.17 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |