| 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-2022-48751: net/smc: Transitional solution for clcsock race issue |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| net/smc: Transitional solution for clcsock race issue |
| |
| We encountered a crash in smc_setsockopt() and it is caused by |
| accessing smc->clcsock after clcsock was released. |
| |
| BUG: kernel NULL pointer dereference, address: 0000000000000020 |
| #PF: supervisor read access in kernel mode |
| #PF: error_code(0x0000) - not-present page |
| PGD 0 P4D 0 |
| Oops: 0000 [#1] PREEMPT SMP PTI |
| CPU: 1 PID: 50309 Comm: nginx Kdump: loaded Tainted: G E 5.16.0-rc4+ #53 |
| RIP: 0010:smc_setsockopt+0x59/0x280 [smc] |
| Call Trace: |
| <TASK> |
| __sys_setsockopt+0xfc/0x190 |
| __x64_sys_setsockopt+0x20/0x30 |
| do_syscall_64+0x34/0x90 |
| entry_SYSCALL_64_after_hwframe+0x44/0xae |
| RIP: 0033:0x7f16ba83918e |
| </TASK> |
| |
| This patch tries to fix it by holding clcsock_release_lock and |
| checking whether clcsock has already been released before access. |
| |
| In case that a crash of the same reason happens in smc_getsockopt() |
| or smc_switch_to_fallback(), this patch also checkes smc->clcsock |
| in them too. And the caller of smc_switch_to_fallback() will identify |
| whether fallback succeeds according to the return value. |
| |
| The Linux kernel CVE team has assigned CVE-2022-48751 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.1 with commit fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9 and fixed in 5.15.19 with commit 38f0bdd548fd2ef5d481b88d8a2bfef968452e34 |
| Issue introduced in 5.1 with commit fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9 and fixed in 5.16.5 with commit 4284225cd8001e134f5cf533a7cd244bbb654d0f |
| Issue introduced in 5.1 with commit fd57770dd198f5b2ddd5b9e6bf282cf98d63adb9 and fixed in 5.17 with commit c0bf3d8a943b6f2e912b7c1de03e2ef28e76f760 |
| Issue introduced in 4.19.299 with commit d1d004585b40c212b338fc8a40cbaaf230ea4703 |
| |
| 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-2022-48751 |
| 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: |
| net/smc/af_smc.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/38f0bdd548fd2ef5d481b88d8a2bfef968452e34 |
| https://git.kernel.org/stable/c/4284225cd8001e134f5cf533a7cd244bbb654d0f |
| https://git.kernel.org/stable/c/c0bf3d8a943b6f2e912b7c1de03e2ef28e76f760 |
