From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E3B0DC433FE for ; Thu, 16 Sep 2021 18:06:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BC54C611CA for ; Thu, 16 Sep 2021 18:06:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346044AbhIPSIQ (ORCPT ); Thu, 16 Sep 2021 14:08:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40452 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1351505AbhIPSGV (ORCPT ); Thu, 16 Sep 2021 14:06:21 -0400 Received: from mail-qv1-xf49.google.com (mail-qv1-xf49.google.com [IPv6:2607:f8b0:4864:20::f49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E8621C061D6C for ; Thu, 16 Sep 2021 09:37:29 -0700 (PDT) Received: by mail-qv1-xf49.google.com with SMTP id r3-20020a0cc403000000b00377a3318261so59374628qvi.11 for ; Thu, 16 Sep 2021 09:37:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=sBm/kHNsJOwk5GfFSoVxh83u5s0/i8ma9jvWkgSwVDk=; b=q7TdV5nqyczGXKbDqK5IDRxzCdI5uOWbNjmqKEblwGVPIUd7/rLYzYGuoU9+4UMuXM TfOY5CKLh+FugU5A/lRxwJDyvdOgGMzc5jIDKFcYdx6wBhkn6JWKMbKcua31Pe9ESdoh Q05R0T3MrLUJGPe07AuurLURngQSxJHl6+fOXiAlH259Zm6f+nCrCPpj0KeHoIIE6vUN hhuo7b1wnzJCfdCKhP5JJf6cAhBlJPV/EW5oO0UOIX+/GDgQVXj8M0JzU9+gdTpr4HNG eWFdo1dTzisoRAqPlaTABMbsDwqjHcuSFMxS4OJQrSmS4RdS5qnTZE2joweuoD1EjhRP 4yJQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=sBm/kHNsJOwk5GfFSoVxh83u5s0/i8ma9jvWkgSwVDk=; b=yK8jfjY+kpOKrvFANB8Ic+fuK//c+h9OGSOtEEByG1Cu+Wy3lzuVP4ClbNvFerNEM9 6w8cjEjylYyqwRMjWskQDHhbOM3awhJo/Jwpp7H07GgGS562KGCyWn7wH1eKwcpBvXgx Oay3qefFv/Nndz9xFZkT4rxnVpQQowLtGblt50S3VNfsiRELMJVt5Rev7Ar/s2BXA13v rfrmiwLi1nTOt352TiVlOjhcJLwOVU3BoTAAODqIs7yi+1lRjYf56sbiv0pqL9dkQaPe /KDeEulVGpMtpLCJ94mLrP983QTy3h5/NOlQjC8dmH1VzgWaNNJdOY8rndz4oHyIL3Nw ycmw== X-Gm-Message-State: AOAM530Ud+AopmYgsHrsWm1GIUPjICK2K5ehwM7hmGEUGWVyIrAGzA3i yH0/PcGPxNfjKmwLFd4oGS2uIMVGJhYpA3oh X-Google-Smtp-Source: ABdhPJxE5nz90QMz6Xzc7bna2lWCZZomuSyI5AGtTrduj1/XGylKS5eKSRFy9SiFmO8ShPGinLF0SyBqMXiycn9B X-Received: from clapinski.waw.corp.google.com ([2a00:79e0:2:11:1fc6:3621:21bf:1e5a]) (user=mclapinski job=sendgmr) by 2002:ad4:4a93:: with SMTP id h19mr6265953qvx.41.1631810249185; Thu, 16 Sep 2021 09:37:29 -0700 (PDT) Date: Thu, 16 Sep 2021 18:37:17 +0200 Message-Id: <20210916163717.3179496-1-mclapinski@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.33.0.309.g3052b89438-goog Subject: [PATCH] ipc: check checkpoint_restore_ns_capable() to modify C/R proc files From: Michal Clapinski To: Andrew Morton Cc: linux-kernel@vger.kernel.org, Michal Clapinski Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This commit removes the requirement to be root to modify sem_next_id, msg_next_id and shm_next_id and checks checkpoint_restore_ns_capable instead. Since those files are specific to the IPC namespace, there is no reason they should require root privileges. This is similar to ns_last_pid, which also only checks checkpoint_restore_ns_capable. Signed-off-by: Michal Clapinski --- ipc/ipc_sysctl.c | 28 ++++++++++++++++++++++------ 1 file changed, 22 insertions(+), 6 deletions(-) diff --git a/ipc/ipc_sysctl.c b/ipc/ipc_sysctl.c index 3f312bf2b116..f8e27203ca49 100644 --- a/ipc/ipc_sysctl.c +++ b/ipc/ipc_sysctl.c @@ -104,6 +104,19 @@ static int proc_ipc_sem_dointvec(struct ctl_table *table, int write, return ret; } +#ifdef CONFIG_CHECKPOINT_RESTORE +static int proc_ipc_dointvec_minmax_checkpoint_restore(struct ctl_table *table, + int write, void *buffer, size_t *lenp, loff_t *ppos) +{ + struct user_namespace *user_ns = current->nsproxy->ipc_ns->user_ns; + + if (write && !checkpoint_restore_ns_capable(user_ns)) + return -EPERM; + + return proc_ipc_dointvec_minmax(table, write, buffer, lenp, ppos); +} +#endif + #else #define proc_ipc_doulongvec_minmax NULL #define proc_ipc_dointvec NULL @@ -111,6 +124,9 @@ static int proc_ipc_sem_dointvec(struct ctl_table *table, int write, #define proc_ipc_dointvec_minmax_orphans NULL #define proc_ipc_auto_msgmni NULL #define proc_ipc_sem_dointvec NULL +#ifdef CONFIG_CHECKPOINT_RESTORE +#define proc_ipc_dointvec_minmax_checkpoint_restore NULL +#endif /* CONFIG_CHECKPOINT_RESTORE */ #endif int ipc_mni = IPCMNI; @@ -198,8 +214,8 @@ static struct ctl_table ipc_kern_table[] = { .procname = "sem_next_id", .data = &init_ipc_ns.ids[IPC_SEM_IDS].next_id, .maxlen = sizeof(init_ipc_ns.ids[IPC_SEM_IDS].next_id), - .mode = 0644, - .proc_handler = proc_ipc_dointvec_minmax, + .mode = 0666, + .proc_handler = proc_ipc_dointvec_minmax_checkpoint_restore, .extra1 = SYSCTL_ZERO, .extra2 = SYSCTL_INT_MAX, }, @@ -207,8 +223,8 @@ static struct ctl_table ipc_kern_table[] = { .procname = "msg_next_id", .data = &init_ipc_ns.ids[IPC_MSG_IDS].next_id, .maxlen = sizeof(init_ipc_ns.ids[IPC_MSG_IDS].next_id), - .mode = 0644, - .proc_handler = proc_ipc_dointvec_minmax, + .mode = 0666, + .proc_handler = proc_ipc_dointvec_minmax_checkpoint_restore, .extra1 = SYSCTL_ZERO, .extra2 = SYSCTL_INT_MAX, }, @@ -216,8 +232,8 @@ static struct ctl_table ipc_kern_table[] = { .procname = "shm_next_id", .data = &init_ipc_ns.ids[IPC_SHM_IDS].next_id, .maxlen = sizeof(init_ipc_ns.ids[IPC_SHM_IDS].next_id), - .mode = 0644, - .proc_handler = proc_ipc_dointvec_minmax, + .mode = 0666, + .proc_handler = proc_ipc_dointvec_minmax_checkpoint_restore, .extra1 = SYSCTL_ZERO, .extra2 = SYSCTL_INT_MAX, }, -- 2.33.0.309.g3052b89438-goog