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Violators will be prosecuted; Wed, 31 Aug 2016 04:10:38 +0530 X-IBM-Helo: d28dlp01.in.ibm.com X-IBM-MailFrom: zohar@linux.vnet.ibm.com X-IBM-RcptTo: linux-kernel@vger.kernel.org; linux-security-module@vger.kernel.org Received: from d28relay04.in.ibm.com (d28relay04.in.ibm.com [9.184.220.61]) by d28dlp01.in.ibm.com (Postfix) with ESMTP id B6C9EE005A; Wed, 31 Aug 2016 04:09:40 +0530 (IST) Received: from d28av01.in.ibm.com (d28av01.in.ibm.com [9.184.220.63]) by d28relay04.in.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u7UMebg122610116; Wed, 31 Aug 2016 04:10:37 +0530 Received: from d28av01.in.ibm.com (localhost [127.0.0.1]) by d28av01.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u7UMeXxM014944; Wed, 31 Aug 2016 04:10:37 +0530 Received: from localhost.localdomain.localdomain (dhcp-9-2-50-238.watson.ibm.com [9.2.50.238]) by d28av01.in.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id u7UMeG7O014112; Wed, 31 Aug 2016 04:10:31 +0530 From: Mimi Zohar To: linux-security-module Cc: Mimi Zohar , linux-ima-devel@lists.sourceforge.net, Dave Young , kexec@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Thiago Jung Bauermann , Andrew Morton Subject: [PATHC v2 3/9] ima: maintain memory size needed for serializing the measurement list Date: Tue, 30 Aug 2016 18:40:05 -0400 X-Mailer: git-send-email 2.1.0 In-Reply-To: <1472596811-9596-1-git-send-email-zohar@linux.vnet.ibm.com> References: <1472596811-9596-1-git-send-email-zohar@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 16083022-0060-0000-0000-0000011A09B2 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 16083022-0061-0000-0000-00000F3B69B4 Message-Id: <1472596811-9596-4-git-send-email-zohar@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2016-08-30_09:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=2 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1608300215 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP In preparation for serializing the binary_runtime_measurements, this patch maintains the amount of memory required. Signed-off-by: Mimi Zohar --- security/integrity/ima/Kconfig | 12 ++++++++++ security/integrity/ima/ima.h | 1 + security/integrity/ima/ima_queue.c | 49 ++++++++++++++++++++++++++++++++++++-- 3 files changed, 60 insertions(+), 2 deletions(-) diff --git a/security/integrity/ima/Kconfig b/security/integrity/ima/Kconfig index 5487827..1c5a1c2 100644 --- a/security/integrity/ima/Kconfig +++ b/security/integrity/ima/Kconfig @@ -27,6 +27,18 @@ config IMA to learn more about IMA. If unsure, say N. +config IMA_KEXEC + bool "Enable carrying the IMA measurement list across a soft boot" + depends on IMA && TCG_TPM && KEXEC_FILE + default n + help + TPM PCRs are only reset on a hard reboot. In order to validate + a TPM's quote after a soft boot, the IMA measurement list of the + running kernel must be saved and restored on boot. + + Depending on the IMA policy, the measurement list can grow to + be very large. + config IMA_MEASURE_PCR_IDX int depends on IMA diff --git a/security/integrity/ima/ima.h b/security/integrity/ima/ima.h index e7b3755..f9cd08e 100644 --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -133,6 +133,7 @@ void ima_print_digest(struct seq_file *m, u8 *digest, u32 size); struct ima_template_desc *ima_template_desc_current(void); int ima_restore_measurement_entry(struct ima_template_entry *entry); int ima_restore_measurement_list(loff_t bufsize, void *buf); +unsigned long ima_get_binary_runtime_size(void); int ima_init_template(void); #ifdef CONFIG_KEXEC_FILE diff --git a/security/integrity/ima/ima_queue.c b/security/integrity/ima/ima_queue.c index 12d1b04..8f0661b 100644 --- a/security/integrity/ima/ima_queue.c +++ b/security/integrity/ima/ima_queue.c @@ -29,6 +29,11 @@ #define AUDIT_CAUSE_LEN_MAX 32 LIST_HEAD(ima_measurements); /* list of all measurements */ +#ifdef CONFIG_IMA_KEXEC +static unsigned long binary_runtime_size; +#else +static unsigned long binary_runtime_size = ULONG_MAX; +#endif /* key: inode (before secure-hashing a file) */ struct ima_h_table ima_htable = { @@ -64,6 +69,24 @@ static struct ima_queue_entry *ima_lookup_digest_entry(u8 *digest_value, return ret; } +/* + * Calculate the memory required for serializing a single + * binary_runtime_measurement list entry, which contains a + * couple of variable length fields (e.g template name and data). + */ +static int get_binary_runtime_size(struct ima_template_entry *entry) +{ + int size = 0; + + size += sizeof(u32); /* pcr */ + size += sizeof(entry->digest); + size += sizeof(int); /* template name size field */ + size += strlen(entry->template_desc->name); + size += sizeof(entry->template_data_len); + size += entry->template_data_len; + return size; +} + /* ima_add_template_entry helper function: * - Add template entry to the measurement list and hash table, for * all entries except those carried across kexec. @@ -90,9 +113,26 @@ static int ima_add_digest_entry(struct ima_template_entry *entry, int flags) key = ima_hash_key(entry->digest); hlist_add_head_rcu(&qe->hnext, &ima_htable.queue[key]); } + + if (binary_runtime_size != ULONG_MAX) { + int size; + + size = get_binary_runtime_size(entry); + binary_runtime_size = (binary_runtime_size < ULONG_MAX - size) ? + binary_runtime_size + size : ULONG_MAX; + } return 0; } +/* + * Return the amount of memory required for serializing the + * entire binary_runtime_measurement list. + */ +unsigned long ima_get_binary_runtime_size(void) +{ + return binary_runtime_size; +}; + static int ima_pcr_extend(const u8 *hash, int pcr) { int result = 0; @@ -106,8 +146,13 @@ static int ima_pcr_extend(const u8 *hash, int pcr) return result; } -/* Add template entry to the measurement list and hash table, - * and extend the pcr. +/* + * Add template entry to the measurement list and hash table, and + * extend the pcr. + * + * On systems which support carrying the IMA measurement list across + * kexec, maintain the total memory size required for serializing the + * binary_runtime_measurements. */ int ima_add_template_entry(struct ima_template_entry *entry, int violation, const char *op, struct inode *inode,