| 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-2024-41012: filelock: Remove locks reliably when fcntl/close race is detected |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| filelock: Remove locks reliably when fcntl/close race is detected |
| |
| When fcntl_setlk() races with close(), it removes the created lock with |
| do_lock_file_wait(). |
| However, LSMs can allow the first do_lock_file_wait() that created the lock |
| while denying the second do_lock_file_wait() that tries to remove the lock. |
| Separately, posix_lock_file() could also fail to |
| remove a lock due to GFP_KERNEL allocation failure (when splitting a range |
| in the middle). |
| |
| After the bug has been triggered, use-after-free reads will occur in |
| lock_get_status() when userspace reads /proc/locks. This can likely be used |
| to read arbitrary kernel memory, but can't corrupt kernel memory. |
| |
| Fix it by calling locks_remove_posix() instead, which is designed to |
| reliably get rid of POSIX locks associated with the given file and |
| files_struct and is also used by filp_flush(). |
| |
| The Linux kernel CVE team has assigned CVE-2024-41012 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 2.6.13 with commit c293621bbf678a3d85e3ed721c3921c8a670610d and fixed in 4.19.319 with commit d30ff33040834c3b9eee29740acd92f9c7ba2250 |
| Issue introduced in 2.6.13 with commit c293621bbf678a3d85e3ed721c3921c8a670610d and fixed in 5.4.281 with commit dc2ce1dfceaa0767211a9d963ddb029ab21c4235 |
| Issue introduced in 2.6.13 with commit c293621bbf678a3d85e3ed721c3921c8a670610d and fixed in 5.10.223 with commit 5661b9c7ec189406c2dde00837aaa4672efb6240 |
| Issue introduced in 2.6.13 with commit c293621bbf678a3d85e3ed721c3921c8a670610d and fixed in 5.15.164 with commit 52c87ab18c76c14d7209646ccb3283b3f5d87b22 |
| Issue introduced in 2.6.13 with commit c293621bbf678a3d85e3ed721c3921c8a670610d and fixed in 6.1.101 with commit ef8fc41cd6f95f9a4a3470f085aecf350569a0b3 |
| Issue introduced in 2.6.13 with commit c293621bbf678a3d85e3ed721c3921c8a670610d and fixed in 6.6.42 with commit 5f5d0799eb0a01d550c21b7894e26b2d9db55763 |
| Issue introduced in 2.6.13 with commit c293621bbf678a3d85e3ed721c3921c8a670610d and fixed in 6.9.9 with commit b6d223942c34057fdfd8f149e763fa823731b224 |
| Issue introduced in 2.6.13 with commit c293621bbf678a3d85e3ed721c3921c8a670610d and fixed in 6.10 with commit 3cad1bc010416c6dd780643476bc59ed742436b9 |
| |
| 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-2024-41012 |
| 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/locks.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/d30ff33040834c3b9eee29740acd92f9c7ba2250 |
| https://git.kernel.org/stable/c/dc2ce1dfceaa0767211a9d963ddb029ab21c4235 |
| https://git.kernel.org/stable/c/5661b9c7ec189406c2dde00837aaa4672efb6240 |
| https://git.kernel.org/stable/c/52c87ab18c76c14d7209646ccb3283b3f5d87b22 |
| https://git.kernel.org/stable/c/ef8fc41cd6f95f9a4a3470f085aecf350569a0b3 |
| https://git.kernel.org/stable/c/5f5d0799eb0a01d550c21b7894e26b2d9db55763 |
| https://git.kernel.org/stable/c/b6d223942c34057fdfd8f149e763fa823731b224 |
| https://git.kernel.org/stable/c/3cad1bc010416c6dd780643476bc59ed742436b9 |
