| 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-2022-49305: drivers: staging: rtl8192u: Fix deadlock in ieee80211_beacons_stop() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| drivers: staging: rtl8192u: Fix deadlock in ieee80211_beacons_stop() |
| |
| There is a deadlock in ieee80211_beacons_stop(), which is shown below: |
| |
| (Thread 1) | (Thread 2) |
| | ieee80211_send_beacon() |
| ieee80211_beacons_stop() | mod_timer() |
| spin_lock_irqsave() //(1) | (wait a time) |
| ... | ieee80211_send_beacon_cb() |
| del_timer_sync() | spin_lock_irqsave() //(2) |
| (wait timer to stop) | ... |
| |
| We hold ieee->beacon_lock in position (1) of thread 1 and use |
| del_timer_sync() to wait timer to stop, but timer handler |
| also need ieee->beacon_lock in position (2) of thread 2. |
| As a result, ieee80211_beacons_stop() will block forever. |
| |
| This patch extracts del_timer_sync() from the protection of |
| spin_lock_irqsave(), which could let timer handler to obtain |
| the needed lock. |
| |
| The Linux kernel CVE team has assigned CVE-2022-49305 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 4.19.247 with commit b465bb2ebf666116c1ac745cb80c65154dc0d27e |
| Fixed in 5.4.198 with commit 1fbe033c52480f7954c057510040fa6286c4ea25 |
| Fixed in 5.10.122 with commit 66f769762f65d957f688f3258755c6ec410bf710 |
| Fixed in 5.15.47 with commit 042915c1bfedd684c1d98a841794ee203200571a |
| Fixed in 5.17.15 with commit ffc9cab7243f8151be37966301307bfd3cda2db3 |
| Fixed in 5.18.4 with commit b34cb54923a6e5ddefbaf358c85c922c6ab456e2 |
| Fixed in 5.19 with commit 806c7b53414934ba2a39449b31fd1a038e500273 |
| |
| 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-2022-49305 |
| 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/rtl8192u/ieee80211/ieee80211_softmac.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/b465bb2ebf666116c1ac745cb80c65154dc0d27e |
| https://git.kernel.org/stable/c/1fbe033c52480f7954c057510040fa6286c4ea25 |
| https://git.kernel.org/stable/c/66f769762f65d957f688f3258755c6ec410bf710 |
| https://git.kernel.org/stable/c/042915c1bfedd684c1d98a841794ee203200571a |
| https://git.kernel.org/stable/c/ffc9cab7243f8151be37966301307bfd3cda2db3 |
| https://git.kernel.org/stable/c/b34cb54923a6e5ddefbaf358c85c922c6ab456e2 |
| https://git.kernel.org/stable/c/806c7b53414934ba2a39449b31fd1a038e500273 |
