From patchwork Wed Nov 22 14:15:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yafang Shao X-Patchwork-Id: 13464944 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="T+zK/skz" Received: from mail-pf1-x434.google.com (mail-pf1-x434.google.com [IPv6:2607:f8b0:4864:20::434]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D3FCE101; Wed, 22 Nov 2023 06:16:24 -0800 (PST) Received: by mail-pf1-x434.google.com with SMTP id d2e1a72fcca58-6cb9dd2ab56so3026856b3a.3; Wed, 22 Nov 2023 06:16:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1700662584; x=1701267384; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=B/MT70BN3YE30s8hUB70yCLmTZgANuDoSG8Z4XUzLV4=; b=T+zK/skzhDiebKP4Rt3BTLsdRCSKtV8NZ3RNSY1sGbnA0CERKiJ+IVZ1Ul/kHFXbqe Bwz7IySrK6Q/LwHMgyvW8L9CvUKRIo/sZvoaxuOgoAvDfQPiKeKAyueR8z2cg8q7iu63 uUwjojG641ZxDgAFSZB9D1S4ga78cxQt5crhqCh5bJLzoEU50dBWafUpk+L3VZ5IgJlm jLAXyOP3g8zUfugxJHdIy3omzQn8p+99EPbwScSMWMfMlBdrjfagpOU+YeaWZedwMLVi k6Lb4kbcs4b4yKTkOrJ8pXnHIs2b+Xm68AX6eqaT2m6StAdHSYbkmuaToR3DieWoB+sF UEzQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1700662584; x=1701267384; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=B/MT70BN3YE30s8hUB70yCLmTZgANuDoSG8Z4XUzLV4=; b=fIo06SHPjQP8g1wFL+wDa2FdrW5xQMS+WzzCNf7k/uomhWmHa7kaCFzAldWXzNns3s WVwjMapOJ6Z+EdXgi4lE4RLFWZwYLQMEnhSxM4wClPUffhivBrMJuJEBkFxQsOtTirEV EvKBTcXXOFQjPbOQdQ9mNQAcfzWjYA/VLzZz5w2HSS+L5+Zo7j7n1MRg+I48TFh5wicI yVTH3JhdTGLaCYTAaEJHyWutgW2fCogbdkgUCgzawQk1TLck8Fbs7ZZUT4ELONNduoZj 10hOthkFxyuhmsT052GxYFq22NE6amnLWE827PuG7hPSkzZm2dcZgqkWg53iDxZxZZFH qSiQ== X-Gm-Message-State: AOJu0YymEXdcdhZWQYMgNMS09XYMCBl4hosm8PxLFO8G6M9c+u35Z99C 2Erx8YKElrqXT+LbMYn5nFk= X-Google-Smtp-Source: AGHT+IHBbCOf8ziLWGyNkSYBub43r5HaSVROiW9/4GVd+5hMyRcAH/fQNAV5DPcevfm6AUJFh0U55A== X-Received: by 2002:a05:6a20:54a4:b0:18b:4c44:d09 with SMTP id i36-20020a056a2054a400b0018b4c440d09mr1612194pzk.0.1700662584215; Wed, 22 Nov 2023 06:16:24 -0800 (PST) Received: from vultr.guest ([2001:19f0:ac01:a71:5400:4ff:fea8:5687]) by smtp.gmail.com with ESMTPSA id p18-20020a63fe12000000b0058988954686sm9356260pgh.90.2023.11.22.06.16.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 22 Nov 2023 06:16:23 -0800 (PST) From: Yafang Shao To: akpm@linux-foundation.org, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com, omosnace@redhat.com, mhocko@suse.com Cc: linux-mm@kvack.org, linux-security-module@vger.kernel.org, bpf@vger.kernel.org, ligang.bdlg@bytedance.com, Yafang Shao Subject: [RFC PATCH v2 4/6] mm, security: Add lsm hook for memory policy adjustment Date: Wed, 22 Nov 2023 14:15:57 +0000 Message-Id: <20231122141559.4228-5-laoar.shao@gmail.com> X-Mailer: git-send-email 2.39.3 In-Reply-To: <20231122141559.4228-1-laoar.shao@gmail.com> References: <20231122141559.4228-1-laoar.shao@gmail.com> Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In a containerized environment, independent memory binding by a user can lead to unexpected system issues or disrupt tasks being run by other users on the same server. If a user genuinely requires memory binding, we will allocate dedicated servers to them by leveraging kubelet deployment. At present, users have the capability to bind their memory to a specific node without explicit agreement or authorization from us. Consequently, a new LSM hook is introduced to mitigate this. This implementation allows us to exercise fine-grained control over memory policy adjustments within our container environment Signed-off-by: Yafang Shao --- include/linux/lsm_hook_defs.h | 3 +++ include/linux/security.h | 9 +++++++++ mm/mempolicy.c | 8 ++++++++ security/security.c | 13 +++++++++++++ 4 files changed, 33 insertions(+) diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index ff217a5ce552..558012719f98 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -419,3 +419,6 @@ LSM_HOOK(int, 0, uring_override_creds, const struct cred *new) LSM_HOOK(int, 0, uring_sqpoll, void) LSM_HOOK(int, 0, uring_cmd, struct io_uring_cmd *ioucmd) #endif /* CONFIG_IO_URING */ + +LSM_HOOK(int, 0, set_mempolicy, unsigned long mode, unsigned short mode_flags, + nodemask_t *nmask, unsigned int flags) diff --git a/include/linux/security.h b/include/linux/security.h index 1d1df326c881..cc4a19a0888c 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -484,6 +484,8 @@ int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen); int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen); int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen); int security_locked_down(enum lockdown_reason what); +int security_set_mempolicy(unsigned long mode, unsigned short mode_flags, + nodemask_t *nmask, unsigned int flags); #else /* CONFIG_SECURITY */ static inline int call_blocking_lsm_notifier(enum lsm_event event, void *data) @@ -1395,6 +1397,13 @@ static inline int security_locked_down(enum lockdown_reason what) { return 0; } + +static inline int +security_set_mempolicy(unsigned long mode, unsigned short mode_flags, + nodemask_t *nmask, unsigned int flags) +{ + return 0; +} #endif /* CONFIG_SECURITY */ #if defined(CONFIG_SECURITY) && defined(CONFIG_WATCH_QUEUE) diff --git a/mm/mempolicy.c b/mm/mempolicy.c index ded2e0e62e24..aa09198cbd29 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1490,6 +1490,10 @@ static long kernel_mbind(unsigned long start, unsigned long len, if (err) return err; + err = security_set_mempolicy(lmode, mode_flags, &nodes, flags); + if (err) + return err; + return do_mbind(start, len, lmode, mode_flags, &nodes, flags); } @@ -1584,6 +1588,10 @@ static long kernel_set_mempolicy(int mode, const unsigned long __user *nmask, if (err) return err; + err = security_set_mempolicy(lmode, mode_flags, &nodes, 0); + if (err) + return err; + return do_set_mempolicy(lmode, mode_flags, &nodes); } diff --git a/security/security.c b/security/security.c index dcb3e7014f9b..685ad7993753 100644 --- a/security/security.c +++ b/security/security.c @@ -5337,3 +5337,16 @@ int security_uring_cmd(struct io_uring_cmd *ioucmd) return call_int_hook(uring_cmd, 0, ioucmd); } #endif /* CONFIG_IO_URING */ + +/** + * security_set_mempolicy() - Check if memory policy can be adjusted + * @mode: The memory policy mode to be set + * @mode_flags: optional mode flags + * @nmask: modemask to which the mode applies + * @flags: mode flags for mbind(2) only + */ +int security_set_mempolicy(unsigned long mode, unsigned short mode_flags, + nodemask_t *nmask, unsigned int flags) +{ + return call_int_hook(set_mempolicy, 0, mode, mode_flags, nmask, flags); +}