| 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-2024-42318: landlock: Don't lose track of restrictions on cred_transfer |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| landlock: Don't lose track of restrictions on cred_transfer |
| |
| When a process' cred struct is replaced, this _almost_ always invokes |
| the cred_prepare LSM hook; but in one special case (when |
| KEYCTL_SESSION_TO_PARENT updates the parent's credentials), the |
| cred_transfer LSM hook is used instead. Landlock only implements the |
| cred_prepare hook, not cred_transfer, so KEYCTL_SESSION_TO_PARENT causes |
| all information on Landlock restrictions to be lost. |
| |
| This basically means that a process with the ability to use the fork() |
| and keyctl() syscalls can get rid of all Landlock restrictions on |
| itself. |
| |
| Fix it by adding a cred_transfer hook that does the same thing as the |
| existing cred_prepare hook. (Implemented by having hook_cred_prepare() |
| call hook_cred_transfer() so that the two functions are less likely to |
| accidentally diverge in the future.) |
| |
| The Linux kernel CVE team has assigned CVE-2024-42318 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.13 with commit 385975dca53eb41031d0cbd1de318eb1bc5d6bb9 and fixed in 5.15.165 with commit 916c648323fa53b89eedb34a0988ddaf01406117 |
| Issue introduced in 5.13 with commit 385975dca53eb41031d0cbd1de318eb1bc5d6bb9 and fixed in 6.1.103 with commit 0d74fd54db0bd0c0c224bef0da8fc95ea9c9f36c |
| Issue introduced in 5.13 with commit 385975dca53eb41031d0cbd1de318eb1bc5d6bb9 and fixed in 6.6.44 with commit 16896914bace82d7811c62f3b6d5320132384f49 |
| Issue introduced in 5.13 with commit 385975dca53eb41031d0cbd1de318eb1bc5d6bb9 and fixed in 6.10.3 with commit b14cc2cf313bd29056fadbc8ecd7f957cf5791ff |
| Issue introduced in 5.13 with commit 385975dca53eb41031d0cbd1de318eb1bc5d6bb9 and fixed in 6.11 with commit 39705a6c29f8a2b93cf5b99528a55366c50014d1 |
| |
| 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-2024-42318 |
| 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: |
| security/landlock/cred.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/916c648323fa53b89eedb34a0988ddaf01406117 |
| https://git.kernel.org/stable/c/0d74fd54db0bd0c0c224bef0da8fc95ea9c9f36c |
| https://git.kernel.org/stable/c/16896914bace82d7811c62f3b6d5320132384f49 |
| https://git.kernel.org/stable/c/b14cc2cf313bd29056fadbc8ecd7f957cf5791ff |
| https://git.kernel.org/stable/c/39705a6c29f8a2b93cf5b99528a55366c50014d1 |
| https://lore.kernel.org/all/20240817.shahka3Ee1iy@digikod.net/ |
| https://www.openwall.com/lists/oss-security/2024/08/17/2 |
| https://bugs.chromium.org/p/project-zero/issues/detail?id=2566 |
