Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932081Ab3EQViM (ORCPT ); Fri, 17 May 2013 17:38:12 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:54421 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757374Ab3EQViJ (ORCPT ); Fri, 17 May 2013 17:38:09 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Steve Grubb , "Eric W. Biederman" , Richard Guy Briggs , Eric Paris Subject: [ 101/102] audit: Make testing for a valid loginuid explicit. Date: Fri, 17 May 2013 14:36:56 -0700 Message-Id: <20130517213254.887451162@linuxfoundation.org> X-Mailer: git-send-email 1.8.3.rc0.20.gb99dd2e In-Reply-To: <20130517213244.277411019@linuxfoundation.org> References: <20130517213244.277411019@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4953 Lines: 155 3.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Eric W. Biederman" commit 780a7654cee8d61819512385e778e4827db4bfbc upstream. audit rule additions containing "-F auid!=4294967295" were failing with EINVAL because of a regression caused by e1760bd. Apparently some userland audit rule sets want to know if loginuid uid has been set and are using a test for auid != 4294967295 to determine that. In practice that is a horrible way to ask if a value has been set, because it relies on subtle implementation details and will break every time the uid implementation in the kernel changes. So add a clean way to test if the audit loginuid has been set, and silently convert the old idiom to the cleaner and more comprehensible new idiom. RGB notes: In upstream, audit_rule_to_entry has been refactored out. This is patch is already upstream in functionally the same form in commit 780a7654cee8d61819512385e778e4827db4bfbc . The decimal constant was cast to unsigned to quiet GCC 4.6 32-bit architecture warnings. Reported-By: Steve Grubb Signed-off-by: "Eric W. Biederman" Tested-by: Richard Guy Briggs Signed-off-by: Eric Paris Backported-by: Richard Guy Briggs Signed-off-by: Greg Kroah-Hartman --- include/linux/audit.h | 5 +++++ include/uapi/linux/audit.h | 1 + kernel/auditfilter.c | 31 ++++++++++++++++++++++++++++++- kernel/auditsc.c | 5 ++++- 4 files changed, 40 insertions(+), 2 deletions(-) --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -390,6 +390,11 @@ static inline void audit_ptrace(struct t #define audit_signals 0 #endif /* CONFIG_AUDITSYSCALL */ +static inline bool audit_loginuid_set(struct task_struct *tsk) +{ + return uid_valid(audit_get_loginuid(tsk)); +} + #ifdef CONFIG_AUDIT /* These are defined in audit.c */ /* Public API */ --- a/include/uapi/linux/audit.h +++ b/include/uapi/linux/audit.h @@ -246,6 +246,7 @@ #define AUDIT_OBJ_TYPE 21 #define AUDIT_OBJ_LEV_LOW 22 #define AUDIT_OBJ_LEV_HIGH 23 +#define AUDIT_LOGINUID_SET 24 /* These are ONLY useful when checking * at syscall exit time (AUDIT_AT_EXIT). */ --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -345,6 +345,12 @@ static struct audit_entry *audit_rule_to f->uid = INVALID_UID; f->gid = INVALID_GID; + /* Support legacy tests for a valid loginuid */ + if ((f->type == AUDIT_LOGINUID) && (f->val == 4294967295U)) { + f->type = AUDIT_LOGINUID_SET; + f->val = 0; + } + err = -EINVAL; if (f->op == Audit_bad) goto exit_free; @@ -352,6 +358,12 @@ static struct audit_entry *audit_rule_to switch(f->type) { default: goto exit_free; + case AUDIT_LOGINUID_SET: + if ((f->val != 0) && (f->val != 1)) + goto exit_free; + if (f->op != Audit_not_equal && f->op != Audit_equal) + goto exit_free; + break; case AUDIT_UID: case AUDIT_EUID: case AUDIT_SUID: @@ -459,7 +471,20 @@ static struct audit_entry *audit_data_to f->gid = INVALID_GID; f->lsm_str = NULL; f->lsm_rule = NULL; - switch(f->type) { + + /* Support legacy tests for a valid loginuid */ + if ((f->type == AUDIT_LOGINUID) && (f->val == 4294967295U)) { + f->type = AUDIT_LOGINUID_SET; + f->val = 0; + } + + switch (f->type) { + case AUDIT_LOGINUID_SET: + if ((f->val != 0) && (f->val != 1)) + goto exit_free; + if (f->op != Audit_not_equal && f->op != Audit_equal) + goto exit_free; + break; case AUDIT_UID: case AUDIT_EUID: case AUDIT_SUID: @@ -1378,6 +1403,10 @@ static int audit_filter_user_rules(struc result = audit_uid_comparator(audit_get_loginuid(current), f->op, f->uid); break; + case AUDIT_LOGINUID_SET: + result = audit_comparator(audit_loginuid_set(current), + f->op, f->val); + break; case AUDIT_SUBJ_USER: case AUDIT_SUBJ_ROLE: case AUDIT_SUBJ_TYPE: --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -742,6 +742,9 @@ static int audit_filter_rules(struct tas if (ctx) result = audit_uid_comparator(tsk->loginuid, f->op, f->uid); break; + case AUDIT_LOGINUID_SET: + result = audit_comparator(audit_loginuid_set(tsk), f->op, f->val); + break; case AUDIT_SUBJ_USER: case AUDIT_SUBJ_ROLE: case AUDIT_SUBJ_TYPE: @@ -2309,7 +2312,7 @@ int audit_set_loginuid(kuid_t loginuid) unsigned int sessionid; #ifdef CONFIG_AUDIT_LOGINUID_IMMUTABLE - if (uid_valid(task->loginuid)) + if (audit_loginuid_set(task)) return -EPERM; #else /* CONFIG_AUDIT_LOGINUID_IMMUTABLE */ if (!capable(CAP_AUDIT_CONTROL)) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/