| 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-2024-26878: quota: Fix potential NULL pointer dereference |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| quota: Fix potential NULL pointer dereference |
| |
| Below race may cause NULL pointer dereference |
| |
| P1 P2 |
| dquot_free_inode quota_off |
| drop_dquot_ref |
| remove_dquot_ref |
| dquots = i_dquot(inode) |
| dquots = i_dquot(inode) |
| srcu_read_lock |
| dquots[cnt]) != NULL (1) |
| dquots[type] = NULL (2) |
| spin_lock(&dquots[cnt]->dq_dqb_lock) (3) |
| .... |
| |
| If dquot_free_inode(or other routines) checks inode's quota pointers (1) |
| before quota_off sets it to NULL(2) and use it (3) after that, NULL pointer |
| dereference will be triggered. |
| |
| So let's fix it by using a temporary pointer to avoid this issue. |
| |
| The Linux kernel CVE team has assigned CVE-2024-26878 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 4.19.311 with commit 8514899c1a4edf802f03c408db901063aa3f05a1 |
| Fixed in 5.4.273 with commit 49669f8e7eb053f91d239df7b1bfb4500255a9d0 |
| Fixed in 5.10.214 with commit 61380537aa6dd32d8a723d98b8f1bd1b11d8fee0 |
| Fixed in 5.15.153 with commit 1ca72a3de915f87232c9a4cb9bebbd3af8ed3e25 |
| Fixed in 6.1.83 with commit 7f9e833fc0f9b47be503af012eb5903086939754 |
| Fixed in 6.6.23 with commit 40a673b4b07efd6f74ff3ab60f38b26aa91ee5d5 |
| Fixed in 6.7.11 with commit f2649d98aa9ca8623149b3cb8df00c944f5655c7 |
| Fixed in 6.8.2 with commit 6afc9f4434fa8063aa768c2bf5bf98583aee0877 |
| Fixed in 6.9 with commit d0aa72604fbd80c8aabb46eda00535ed35570f1f |
| |
| 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-2024-26878 |
| 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/quota/dquot.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/8514899c1a4edf802f03c408db901063aa3f05a1 |
| https://git.kernel.org/stable/c/49669f8e7eb053f91d239df7b1bfb4500255a9d0 |
| https://git.kernel.org/stable/c/61380537aa6dd32d8a723d98b8f1bd1b11d8fee0 |
| https://git.kernel.org/stable/c/1ca72a3de915f87232c9a4cb9bebbd3af8ed3e25 |
| https://git.kernel.org/stable/c/7f9e833fc0f9b47be503af012eb5903086939754 |
| https://git.kernel.org/stable/c/40a673b4b07efd6f74ff3ab60f38b26aa91ee5d5 |
| https://git.kernel.org/stable/c/f2649d98aa9ca8623149b3cb8df00c944f5655c7 |
| https://git.kernel.org/stable/c/6afc9f4434fa8063aa768c2bf5bf98583aee0877 |
| https://git.kernel.org/stable/c/d0aa72604fbd80c8aabb46eda00535ed35570f1f |
