| 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-2022-49303: drivers: staging: rtl8192eu: Fix deadlock in rtw_joinbss_event_prehandle |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| drivers: staging: rtl8192eu: Fix deadlock in rtw_joinbss_event_prehandle |
| |
| There is a deadlock in rtw_joinbss_event_prehandle(), which is shown below: |
| |
| (Thread 1) | (Thread 2) |
| | _set_timer() |
| rtw_joinbss_event_prehandle()| mod_timer() |
| spin_lock_bh() //(1) | (wait a time) |
| ... | rtw_join_timeout_handler() |
| | _rtw_join_timeout_handler() |
| del_timer_sync() | spin_lock_bh() //(2) |
| (wait timer to stop) | ... |
| |
| We hold pmlmepriv->lock in position (1) of thread 1 and |
| use del_timer_sync() to wait timer to stop, but timer handler |
| also need pmlmepriv->lock in position (2) of thread 2. |
| As a result, rtw_joinbss_event_prehandle() will block forever. |
| |
| This patch extracts del_timer_sync() from the protection of |
| spin_lock_bh(), which could let timer handler to obtain |
| the needed lock. What`s more, we change spin_lock_bh() to |
| spin_lock_irq() in _rtw_join_timeout_handler() in order to |
| prevent deadlock. |
| |
| The Linux kernel CVE team has assigned CVE-2022-49303 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 5.18.4 with commit 25cf414b0610fea29d8e045f315648d9007c9a46 |
| Fixed in 5.19 with commit 0fcddf9c7c10202946d5b19409efbdff744fba88 |
| |
| 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-2022-49303 |
| 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/staging/r8188eu/core/rtw_mlme.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/25cf414b0610fea29d8e045f315648d9007c9a46 |
| https://git.kernel.org/stable/c/0fcddf9c7c10202946d5b19409efbdff744fba88 |
