| 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-2025-21834: seccomp: passthrough uretprobe systemcall without filtering |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| seccomp: passthrough uretprobe systemcall without filtering |
| |
| When attaching uretprobes to processes running inside docker, the attached |
| process is segfaulted when encountering the retprobe. |
| |
| The reason is that now that uretprobe is a system call the default seccomp |
| filters in docker block it as they only allow a specific set of known |
| syscalls. This is true for other userspace applications which use seccomp |
| to control their syscall surface. |
| |
| Since uretprobe is a "kernel implementation detail" system call which is |
| not used by userspace application code directly, it is impractical and |
| there's very little point in forcing all userspace applications to |
| explicitly allow it in order to avoid crashing tracked processes. |
| |
| Pass this systemcall through seccomp without depending on configuration. |
| |
| Note: uretprobe is currently only x86_64 and isn't expected to ever be |
| supported in i386. |
| |
| [kees: minimized changes for easier backporting, tweaked commit log] |
| |
| The Linux kernel CVE team has assigned CVE-2025-21834 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.11 with commit ff474a78cef5cb5f32be52fe25b78441327a2e7c and fixed in 6.12.14 with commit 5a262628f4cf2437d863fe41f9d427177b87664c |
| Issue introduced in 6.11 with commit ff474a78cef5cb5f32be52fe25b78441327a2e7c and fixed in 6.13.3 with commit fa80018aa5be10c35e9fa896b7b4061a8dce3eed |
| Issue introduced in 6.11 with commit ff474a78cef5cb5f32be52fe25b78441327a2e7c and fixed in 6.14 with commit cf6cb56ef24410fb5308f9655087f1eddf4452e6 |
| |
| 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-2025-21834 |
| 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: |
| kernel/seccomp.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/5a262628f4cf2437d863fe41f9d427177b87664c |
| https://git.kernel.org/stable/c/fa80018aa5be10c35e9fa896b7b4061a8dce3eed |
| https://git.kernel.org/stable/c/cf6cb56ef24410fb5308f9655087f1eddf4452e6 |
