| 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-2024-38570: gfs2: Fix potential glock use-after-free on unmount |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| gfs2: Fix potential glock use-after-free on unmount |
| |
| When a DLM lockspace is released and there ares still locks in that |
| lockspace, DLM will unlock those locks automatically. Commit |
| fb6791d100d1b started exploiting this behavior to speed up filesystem |
| unmount: gfs2 would simply free glocks it didn't want to unlock and then |
| release the lockspace. This didn't take the bast callbacks for |
| asynchronous lock contention notifications into account, which remain |
| active until until a lock is unlocked or its lockspace is released. |
| |
| To prevent those callbacks from accessing deallocated objects, put the |
| glocks that should not be unlocked on the sd_dead_glocks list, release |
| the lockspace, and only then free those glocks. |
| |
| As an additional measure, ignore unexpected ast and bast callbacks if |
| the receiving glock is dead. |
| |
| The Linux kernel CVE team has assigned CVE-2024-38570 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 3.8 with commit fb6791d100d1bba20b5cdbc4912e1f7086ec60f8 and fixed in 6.6.33 with commit 0636b34b44589b142700ac137b5f69802cfe2e37 |
| Issue introduced in 3.8 with commit fb6791d100d1bba20b5cdbc4912e1f7086ec60f8 and fixed in 6.8.12 with commit e42e8a24d7f02d28763d16ca7ec5fc6d1f142af0 |
| Issue introduced in 3.8 with commit fb6791d100d1bba20b5cdbc4912e1f7086ec60f8 and fixed in 6.9.3 with commit 501cd8fabf621d10bd4893e37f6ce6c20523c8ca |
| Issue introduced in 3.8 with commit fb6791d100d1bba20b5cdbc4912e1f7086ec60f8 and fixed in 6.10 with commit d98779e687726d8f8860f1c54b5687eec5f63a73 |
| |
| 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-2024-38570 |
| 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: |
| fs/gfs2/glock.c |
| fs/gfs2/glock.h |
| fs/gfs2/incore.h |
| fs/gfs2/lock_dlm.c |
| fs/gfs2/ops_fstype.c |
| fs/gfs2/super.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/0636b34b44589b142700ac137b5f69802cfe2e37 |
| https://git.kernel.org/stable/c/e42e8a24d7f02d28763d16ca7ec5fc6d1f142af0 |
| https://git.kernel.org/stable/c/501cd8fabf621d10bd4893e37f6ce6c20523c8ca |
| https://git.kernel.org/stable/c/d98779e687726d8f8860f1c54b5687eec5f63a73 |
