| From bippy-1.1.0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@kernel.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2022-49804: s390: avoid using global register for current_stack_pointer |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| s390: avoid using global register for current_stack_pointer |
| |
| Commit 30de14b1884b ("s390: current_stack_pointer shouldn't be a |
| function") made current_stack_pointer a global register variable like |
| on many other architectures. Unfortunately on s390 it uncovers old |
| gcc bug which is fixed only since gcc-9.1 [gcc commit 3ad7fed1cc87 |
| ("S/390: Fix PR89775. Stackpointer save/restore instructions removed")] |
| and backported to gcc-8.4 and later. Due to this bug gcc versions prior |
| to 8.4 generate broken code which leads to stack corruptions. |
| |
| Current minimal gcc version required to build the kernel is declared |
| as 5.1. It is not possible to fix all old gcc versions, so work |
| around this problem by avoiding using global register variable for |
| current_stack_pointer. |
| |
| The Linux kernel CVE team has assigned CVE-2022-49804 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.18 with commit 30de14b1884ba609fc1acfba5b40309e3a6ccefe and fixed in 6.0.10 with commit a478952a8ac44e32316dc046a063a7dc34825aa6 |
| Issue introduced in 5.18 with commit 30de14b1884ba609fc1acfba5b40309e3a6ccefe and fixed in 6.1 with commit e3c11025bcd2142a61abe5806b2f86a0e78118df |
| |
| 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-2022-49804 |
| 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/include/asm/processor.h |
| |
| |
| 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/a478952a8ac44e32316dc046a063a7dc34825aa6 |
| https://git.kernel.org/stable/c/e3c11025bcd2142a61abe5806b2f86a0e78118df |
