| 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-2021-47494: cfg80211: fix management registrations locking |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| cfg80211: fix management registrations locking |
| |
| The management registrations locking was broken, the list was |
| locked for each wdev, but cfg80211_mgmt_registrations_update() |
| iterated it without holding all the correct spinlocks, causing |
| list corruption. |
| |
| Rather than trying to fix it with fine-grained locking, just |
| move the lock to the wiphy/rdev (still need the list on each |
| wdev), we already need to hold the wdev lock to change it, so |
| there's no contention on the lock in any case. This trivially |
| fixes the bug since we hold one wdev's lock already, and now |
| will hold the lock that protects all lists. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47494 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.8 with commit 6cd536fe62ef58d7c4eac2da07ab0ed7fd19010d and fixed in 5.10.77 with commit 4c22227e39c7a0b4dab55617ee8d34d171fab8d4 |
| Issue introduced in 5.8 with commit 6cd536fe62ef58d7c4eac2da07ab0ed7fd19010d and fixed in 5.14.16 with commit 3c897f39b71fe68f90599f6a45b5f7bf5618420e |
| Issue introduced in 5.8 with commit 6cd536fe62ef58d7c4eac2da07ab0ed7fd19010d and fixed in 5.15 with commit 09b1d5dc6ce1c9151777f6c4e128a59457704c97 |
| |
| 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-2021-47494 |
| 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: |
| include/net/cfg80211.h |
| net/wireless/core.c |
| net/wireless/core.h |
| net/wireless/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/4c22227e39c7a0b4dab55617ee8d34d171fab8d4 |
| https://git.kernel.org/stable/c/3c897f39b71fe68f90599f6a45b5f7bf5618420e |
| https://git.kernel.org/stable/c/09b1d5dc6ce1c9151777f6c4e128a59457704c97 |
