| 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-2023-52598: s390/ptrace: handle setting of fpc register correctly |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| s390/ptrace: handle setting of fpc register correctly |
| |
| If the content of the floating point control (fpc) register of a traced |
| process is modified with the ptrace interface the new value is tested for |
| validity by temporarily loading it into the fpc register. |
| |
| This may lead to corruption of the fpc register of the tracing process: |
| if an interrupt happens while the value is temporarily loaded into the |
| fpc register, and within interrupt context floating point or vector |
| registers are used, the current fp/vx registers are saved with |
| save_fpu_regs() assuming they belong to user space and will be loaded into |
| fp/vx registers when returning to user space. |
| |
| test_fp_ctl() restores the original user space fpc register value, however |
| it will be discarded, when returning to user space. |
| |
| In result the tracer will incorrectly continue to run with the value that |
| was supposed to be used for the traced process. |
| |
| Fix this by saving fpu register contents with save_fpu_regs() before using |
| test_fp_ctl(). |
| |
| The Linux kernel CVE team has assigned CVE-2023-52598 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 4.19.307 with commit 6ccf904aac0292e1f6b1a1be6c407c414f7cf713 |
| Fixed in 5.4.269 with commit 6d0822f2cc9b153bf2df49a84599195a2e0d21a8 |
| Fixed in 5.10.210 with commit 856caf2730ea18cb39e95833719c02a02447dc0a |
| Fixed in 5.15.149 with commit 28a1f492cb527f64593457a0a0f0d809b3f36c25 |
| Fixed in 6.1.77 with commit 7a4d6481fbdd661f9e40e95febb95e3dee82bad3 |
| Fixed in 6.6.16 with commit 02c6bbfb08bad78dd014e24c7b893723c15ec7a1 |
| Fixed in 6.7.4 with commit bdce67df7f12fb0409fbc604ce7c4254703f56d4 |
| Fixed in 6.8 with commit 8b13601d19c541158a6e18b278c00ba69ae37829 |
| |
| 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-2023-52598 |
| 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: |
| arch/s390/kernel/ptrace.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/6ccf904aac0292e1f6b1a1be6c407c414f7cf713 |
| https://git.kernel.org/stable/c/6d0822f2cc9b153bf2df49a84599195a2e0d21a8 |
| https://git.kernel.org/stable/c/856caf2730ea18cb39e95833719c02a02447dc0a |
| https://git.kernel.org/stable/c/28a1f492cb527f64593457a0a0f0d809b3f36c25 |
| https://git.kernel.org/stable/c/7a4d6481fbdd661f9e40e95febb95e3dee82bad3 |
| https://git.kernel.org/stable/c/02c6bbfb08bad78dd014e24c7b893723c15ec7a1 |
| https://git.kernel.org/stable/c/bdce67df7f12fb0409fbc604ce7c4254703f56d4 |
| https://git.kernel.org/stable/c/8b13601d19c541158a6e18b278c00ba69ae37829 |
