| 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-2024-35793: debugfs: fix wait/cancellation handling during remove |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| debugfs: fix wait/cancellation handling during remove |
| |
| Ben Greear further reports deadlocks during concurrent debugfs |
| remove while files are being accessed, even though the code in |
| question now uses debugfs cancellations. Turns out that despite |
| all the review on the locking, we missed completely that the |
| logic is wrong: if the refcount hits zero we can finish (and |
| need not wait for the completion), but if it doesn't we have |
| to trigger all the cancellations. As written, we can _never_ |
| get into the loop triggering the cancellations. Fix this, and |
| explain it better while at it. |
| |
| The Linux kernel CVE team has assigned CVE-2024-35793 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.7 with commit 8c88a474357ead632b07c70bf7f119ace8c3b39e and fixed in 6.7.12 with commit e88b5ae01901c4a655a53158397746334778a57b |
| Issue introduced in 6.7 with commit 8c88a474357ead632b07c70bf7f119ace8c3b39e and fixed in 6.8.3 with commit 3d08cca5fd0aabb62b7015067ab40913b33da906 |
| Issue introduced in 6.7 with commit 8c88a474357ead632b07c70bf7f119ace8c3b39e and fixed in 6.9 with commit 952c3fce297f12c7ff59380adb66b564e2bc9b64 |
| |
| 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-2024-35793 |
| 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/debugfs/inode.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/e88b5ae01901c4a655a53158397746334778a57b |
| https://git.kernel.org/stable/c/3d08cca5fd0aabb62b7015067ab40913b33da906 |
| https://git.kernel.org/stable/c/952c3fce297f12c7ff59380adb66b564e2bc9b64 |
