Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:59074 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753266AbdCHNOv (ORCPT ); Wed, 8 Mar 2017 08:14:51 -0500 Subject: Patch "ima: fix ima_d_path() possible race with rename" has been added to the 4.9-stable tree To: zohar@linux.vnet.ibm.com, gregkh@linuxfoundation.org, viro@zeniv.linux.org.uk Cc: , From: Date: Wed, 08 Mar 2017 14:13:39 +0100 Message-ID: <1488978819064@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled ima: fix ima_d_path() possible race with rename to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ima-fix-ima_d_path-possible-race-with-rename.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >From bc15ed663e7e53ee4dc3e60f8d09c93a0528c694 Mon Sep 17 00:00:00 2001 From: Mimi Zohar Date: Tue, 17 Jan 2017 06:45:41 -0500 Subject: ima: fix ima_d_path() possible race with rename From: Mimi Zohar commit bc15ed663e7e53ee4dc3e60f8d09c93a0528c694 upstream. On failure to return a pathname from ima_d_path(), a pointer to dname is returned, which is subsequently used in the IMA measurement list, the IMA audit records, and other audit logging. Saving the pointer to dname for later use has the potential to race with rename. Intead of returning a pointer to dname on failure, this patch returns a pointer to a copy of the filename. Reported-by: Al Viro Signed-off-by: Mimi Zohar Signed-off-by: Greg Kroah-Hartman --- security/integrity/ima/ima.h | 2 +- security/integrity/ima/ima_api.c | 20 ++++++++++++++++++-- security/integrity/ima/ima_main.c | 8 +++++--- 3 files changed, 24 insertions(+), 6 deletions(-) --- a/security/integrity/ima/ima.h +++ b/security/integrity/ima/ima.h @@ -173,7 +173,7 @@ int ima_store_template(struct ima_templa struct inode *inode, const unsigned char *filename, int pcr); void ima_free_template_entry(struct ima_template_entry *entry); -const char *ima_d_path(const struct path *path, char **pathbuf); +const char *ima_d_path(const struct path *path, char **pathbuf, char *filename); /* IMA policy related functions */ int ima_match_policy(struct inode *inode, enum ima_hooks func, int mask, --- a/security/integrity/ima/ima_api.c +++ b/security/integrity/ima/ima_api.c @@ -318,7 +318,17 @@ void ima_audit_measurement(struct integr iint->flags |= IMA_AUDITED; } -const char *ima_d_path(const struct path *path, char **pathbuf) +/* + * ima_d_path - return a pointer to the full pathname + * + * Attempt to return a pointer to the full pathname for use in the + * IMA measurement list, IMA audit records, and auditing logs. + * + * On failure, return a pointer to a copy of the filename, not dname. + * Returning a pointer to dname, could result in using the pointer + * after the memory has been freed. + */ +const char *ima_d_path(const struct path *path, char **pathbuf, char *namebuf) { char *pathname = NULL; @@ -331,5 +341,11 @@ const char *ima_d_path(const struct path pathname = NULL; } } - return pathname ?: (const char *)path->dentry->d_name.name; + + if (!pathname) { + strlcpy(namebuf, path->dentry->d_name.name, NAME_MAX); + pathname = namebuf; + } + + return pathname; } --- a/security/integrity/ima/ima_main.c +++ b/security/integrity/ima/ima_main.c @@ -83,6 +83,7 @@ static void ima_rdwr_violation_check(str const char **pathname) { struct inode *inode = file_inode(file); + char filename[NAME_MAX]; fmode_t mode = file->f_mode; bool send_tomtou = false, send_writers = false; @@ -102,7 +103,7 @@ static void ima_rdwr_violation_check(str if (!send_tomtou && !send_writers) return; - *pathname = ima_d_path(&file->f_path, pathbuf); + *pathname = ima_d_path(&file->f_path, pathbuf, filename); if (send_tomtou) ima_add_violation(file, *pathname, iint, @@ -161,6 +162,7 @@ static int process_measurement(struct fi struct integrity_iint_cache *iint = NULL; struct ima_template_desc *template_desc; char *pathbuf = NULL; + char filename[NAME_MAX]; const char *pathname = NULL; int rc = -ENOMEM, action, must_appraise; int pcr = CONFIG_IMA_MEASURE_PCR_IDX; @@ -239,8 +241,8 @@ static int process_measurement(struct fi goto out_digsig; } - if (!pathname) /* ima_rdwr_violation possibly pre-fetched */ - pathname = ima_d_path(&file->f_path, &pathbuf); + if (!pathbuf) /* ima_rdwr_violation possibly pre-fetched */ + pathname = ima_d_path(&file->f_path, &pathbuf, filename); if (action & IMA_MEASURE) ima_store_measurement(iint, file, pathname, Patches currently in stable-queue which might be from zohar@linux.vnet.ibm.com are queue-4.9/ima-fix-ima_d_path-possible-race-with-rename.patch