| 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-2024-58042: rhashtable: Fix potential deadlock by moving schedule_work outside lock |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| rhashtable: Fix potential deadlock by moving schedule_work outside lock |
| |
| Move the hash table growth check and work scheduling outside the |
| rht lock to prevent a possible circular locking dependency. |
| |
| The original implementation could trigger a lockdep warning due to |
| a potential deadlock scenario involving nested locks between |
| rhashtable bucket, rq lock, and dsq lock. By relocating the |
| growth check and work scheduling after releasing the rth lock, we break |
| this potential deadlock chain. |
| |
| This change expands the flexibility of rhashtable by removing |
| restrictive locking that previously limited its use in scheduler |
| and workqueue contexts. |
| |
| Import to say that this calls rht_grow_above_75(), which reads from |
| struct rhashtable without holding the lock, if this is a problem, we can |
| move the check to the lock, and schedule the workqueue after the lock. |
| |
| |
| Modified so that atomic_inc is also moved outside of the bucket |
| lock along with the growth above 75% check. |
| |
| The Linux kernel CVE team has assigned CVE-2024-58042 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.12 with commit f0e1a0643a59bf1f922fa209cec86a170b784f3f and fixed in 6.12.13 with commit eb2e58484b838fb4e777ee9721bb9e20e6ca971d |
| Issue introduced in 6.12 with commit f0e1a0643a59bf1f922fa209cec86a170b784f3f and fixed in 6.13.2 with commit ced8ce3c83a7150c5f5d371a8c332d7bc7f9b66d |
| Issue introduced in 6.12 with commit f0e1a0643a59bf1f922fa209cec86a170b784f3f and fixed in 6.14 with commit e1d3422c95f003eba241c176adfe593c33e8a8f6 |
| |
| 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-2024-58042 |
| 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: |
| lib/rhashtable.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/eb2e58484b838fb4e777ee9721bb9e20e6ca971d |
| https://git.kernel.org/stable/c/ced8ce3c83a7150c5f5d371a8c332d7bc7f9b66d |
| https://git.kernel.org/stable/c/e1d3422c95f003eba241c176adfe593c33e8a8f6 |
