| 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-2024-27058: tmpfs: fix race on handling dquot rbtree |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| tmpfs: fix race on handling dquot rbtree |
| |
| A syzkaller reproducer found a race while attempting to remove dquot |
| information from the rb tree. |
| |
| Fetching the rb_tree root node must also be protected by the |
| dqopt->dqio_sem, otherwise, giving the right timing, shmem_release_dquot() |
| will trigger a warning because it couldn't find a node in the tree, when |
| the real reason was the root node changing before the search starts: |
| |
| Thread 1 Thread 2 |
| - shmem_release_dquot() - shmem_{acquire,release}_dquot() |
| |
| - fetch ROOT - Fetch ROOT |
| |
| - acquire dqio_sem |
| - wait dqio_sem |
| |
| - do something, triger a tree rebalance |
| - release dqio_sem |
| |
| - acquire dqio_sem |
| - start searching for the node, but |
| from the wrong location, missing |
| the node, and triggering a warning. |
| |
| The Linux kernel CVE team has assigned CVE-2024-27058 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.6 with commit eafc474e202978ac735c551d5ee1eb8c02e2be54 and fixed in 6.6.24 with commit c7077f43f30d817d10a9f8245e51576ac114b2f0 |
| Issue introduced in 6.6 with commit eafc474e202978ac735c551d5ee1eb8c02e2be54 and fixed in 6.7.12 with commit 617d55b90e73c7b4aa2733ca6cc3f9b72d1124bb |
| Issue introduced in 6.6 with commit eafc474e202978ac735c551d5ee1eb8c02e2be54 and fixed in 6.8.3 with commit f82f184874d2761ebaa60dccf577921a0dbb3810 |
| Issue introduced in 6.6 with commit eafc474e202978ac735c551d5ee1eb8c02e2be54 and fixed in 6.9 with commit 0a69b6b3a026543bc215ccc866d0aea5579e6ce2 |
| |
| 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-2024-27058 |
| 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: |
| mm/shmem_quota.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/c7077f43f30d817d10a9f8245e51576ac114b2f0 |
| https://git.kernel.org/stable/c/617d55b90e73c7b4aa2733ca6cc3f9b72d1124bb |
| https://git.kernel.org/stable/c/f82f184874d2761ebaa60dccf577921a0dbb3810 |
| https://git.kernel.org/stable/c/0a69b6b3a026543bc215ccc866d0aea5579e6ce2 |
