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Diffstat (limited to 'kernel/auditsc.c')
| -rw-r--r-- | kernel/auditsc.c | 2426 |
1 files changed, 2426 insertions, 0 deletions
diff --git a/kernel/auditsc.c b/kernel/auditsc.c new file mode 100644 index 000000000..9fb9d1cb8 --- /dev/null +++ b/kernel/auditsc.c @@ -0,0 +1,2426 @@ +/* auditsc.c -- System-call auditing support + * Handles all system-call specific auditing features. + * + * Copyright 2003-2004 Red Hat Inc., Durham, North Carolina. + * Copyright 2005 Hewlett-Packard Development Company, L.P. + * Copyright (C) 2005, 2006 IBM Corporation + * All Rights Reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + * Written by Rickard E. (Rik) Faith <faith@redhat.com> + * + * Many of the ideas implemented here are from Stephen C. Tweedie, + * especially the idea of avoiding a copy by using getname. + * + * The method for actual interception of syscall entry and exit (not in + * this file -- see entry.S) is based on a GPL'd patch written by + * okir@suse.de and Copyright 2003 SuSE Linux AG. + * + * POSIX message queue support added by George Wilson <ltcgcw@us.ibm.com>, + * 2006. + * + * The support of additional filter rules compares (>, <, >=, <=) was + * added by Dustin Kirkland <dustin.kirkland@us.ibm.com>, 2005. + * + * Modified by Amy Griffis <amy.griffis@hp.com> to collect additional + * filesystem information. + * + * Subject and object context labeling support added by <danjones@us.ibm.com> + * and <dustin.kirkland@us.ibm.com> for LSPP certification compliance. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/init.h> +#include <asm/types.h> +#include <linux/atomic.h> +#include <linux/fs.h> +#include <linux/namei.h> +#include <linux/mm.h> +#include <linux/export.h> +#include <linux/slab.h> +#include <linux/mount.h> +#include <linux/socket.h> +#include <linux/mqueue.h> +#include <linux/audit.h> +#include <linux/personality.h> +#include <linux/time.h> +#include <linux/netlink.h> +#include <linux/compiler.h> +#include <asm/unistd.h> +#include <linux/security.h> +#include <linux/list.h> +#include <linux/tty.h> +#include <linux/binfmts.h> +#include <linux/highmem.h> +#include <linux/syscalls.h> +#include <asm/syscall.h> +#include <linux/capability.h> +#include <linux/fs_struct.h> +#include <linux/compat.h> +#include <linux/ctype.h> +#include <linux/string.h> +#include <uapi/linux/limits.h> + +#include "audit.h" + +/* flags stating the success for a syscall */ +#define AUDITSC_INVALID 0 +#define AUDITSC_SUCCESS 1 +#define AUDITSC_FAILURE 2 + +/* no execve audit message should be longer than this (userspace limits) */ +#define MAX_EXECVE_AUDIT_LEN 7500 + +/* max length to print of cmdline/proctitle value during audit */ +#define MAX_PROCTITLE_AUDIT_LEN 128 + +/* number of audit rules */ +int audit_n_rules; + +/* determines whether we collect data for signals sent */ +int audit_signals; + +struct audit_aux_data { + struct audit_aux_data *next; + int type; +}; + +#define AUDIT_AUX_IPCPERM 0 + +/* Number of target pids per aux struct. */ +#define AUDIT_AUX_PIDS 16 + +struct audit_aux_data_pids { + struct audit_aux_data d; + pid_t target_pid[AUDIT_AUX_PIDS]; + kuid_t target_auid[AUDIT_AUX_PIDS]; + kuid_t target_uid[AUDIT_AUX_PIDS]; + unsigned int target_sessionid[AUDIT_AUX_PIDS]; + u32 target_sid[AUDIT_AUX_PIDS]; + char target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN]; + int pid_count; +}; + +struct audit_aux_data_bprm_fcaps { + struct audit_aux_data d; + struct audit_cap_data fcap; + unsigned int fcap_ver; + struct audit_cap_data old_pcap; + struct audit_cap_data new_pcap; +}; + +struct audit_tree_refs { + struct audit_tree_refs *next; + struct audit_chunk *c[31]; +}; + +static int audit_match_perm(struct audit_context *ctx, int mask) +{ + unsigned n; + if (unlikely(!ctx)) + return 0; + n = ctx->major; + + switch (audit_classify_syscall(ctx->arch, n)) { + case 0: /* native */ + if ((mask & AUDIT_PERM_WRITE) && + audit_match_class(AUDIT_CLASS_WRITE, n)) + return 1; + if ((mask & AUDIT_PERM_READ) && + audit_match_class(AUDIT_CLASS_READ, n)) + return 1; + if ((mask & AUDIT_PERM_ATTR) && + audit_match_class(AUDIT_CLASS_CHATTR, n)) + return 1; + return 0; + case 1: /* 32bit on biarch */ + if ((mask & AUDIT_PERM_WRITE) && + audit_match_class(AUDIT_CLASS_WRITE_32, n)) + return 1; + if ((mask & AUDIT_PERM_READ) && + audit_match_class(AUDIT_CLASS_READ_32, n)) + return 1; + if ((mask & AUDIT_PERM_ATTR) && + audit_match_class(AUDIT_CLASS_CHATTR_32, n)) + return 1; + return 0; + case 2: /* open */ + return mask & ACC_MODE(ctx->argv[1]); + case 3: /* openat */ + return mask & ACC_MODE(ctx->argv[2]); + case 4: /* socketcall */ + return ((mask & AUDIT_PERM_WRITE) && ctx->argv[0] == SYS_BIND); + case 5: /* execve */ + return mask & AUDIT_PERM_EXEC; + default: + return 0; + } +} + +static int audit_match_filetype(struct audit_context *ctx, int val) +{ + struct audit_names *n; + umode_t mode = (umode_t)val; + + if (unlikely(!ctx)) + return 0; + + list_for_each_entry(n, &ctx->names_list, list) { + if ((n->ino != -1) && + ((n->mode & S_IFMT) == mode)) + return 1; + } + + return 0; +} + +/* + * We keep a linked list of fixed-sized (31 pointer) arrays of audit_chunk *; + * ->first_trees points to its beginning, ->trees - to the current end of data. + * ->tree_count is the number of free entries in array pointed to by ->trees. + * Original condition is (NULL, NULL, 0); as soon as it grows we never revert to NULL, + * "empty" becomes (p, p, 31) afterwards. We don't shrink the list (and seriously, + * it's going to remain 1-element for almost any setup) until we free context itself. + * References in it _are_ dropped - at the same time we free/drop aux stuff. + */ + +#ifdef CONFIG_AUDIT_TREE +static void audit_set_auditable(struct audit_context *ctx) +{ + if (!ctx->prio) { + ctx->prio = 1; + ctx->current_state = AUDIT_RECORD_CONTEXT; + } +} + +static int put_tree_ref(struct audit_context *ctx, struct audit_chunk *chunk) +{ + struct audit_tree_refs *p = ctx->trees; + int left = ctx->tree_count; + if (likely(left)) { + p->c[--left] = chunk; + ctx->tree_count = left; + return 1; + } + if (!p) + return 0; + p = p->next; + if (p) { + p->c[30] = chunk; + ctx->trees = p; + ctx->tree_count = 30; + return 1; + } + return 0; +} + +static int grow_tree_refs(struct audit_context *ctx) +{ + struct audit_tree_refs *p = ctx->trees; + ctx->trees = kzalloc(sizeof(struct audit_tree_refs), GFP_KERNEL); + if (!ctx->trees) { + ctx->trees = p; + return 0; + } + if (p) + p->next = ctx->trees; + else + ctx->first_trees = ctx->trees; + ctx->tree_count = 31; + return 1; +} +#endif + +static void unroll_tree_refs(struct audit_context *ctx, + struct audit_tree_refs *p, int count) +{ +#ifdef CONFIG_AUDIT_TREE + struct audit_tree_refs *q; + int n; + if (!p) { + /* we started with empty chain */ + p = ctx->first_trees; + count = 31; + /* if the very first allocation has failed, nothing to do */ + if (!p) + return; + } + n = count; + for (q = p; q != ctx->trees; q = q->next, n = 31) { + while (n--) { + audit_put_chunk(q->c[n]); + q->c[n] = NULL; + } + } + while (n-- > ctx->tree_count) { + audit_put_chunk(q->c[n]); + q->c[n] = NULL; + } + ctx->trees = p; + ctx->tree_count = count; +#endif +} + +static void free_tree_refs(struct audit_context *ctx) +{ + struct audit_tree_refs *p, *q; + for (p = ctx->first_trees; p; p = q) { + q = p->next; + kfree(p); + } +} + +static int match_tree_refs(struct audit_context *ctx, struct audit_tree *tree) +{ +#ifdef CONFIG_AUDIT_TREE + struct audit_tree_refs *p; + int n; + if (!tree) + return 0; + /* full ones */ + for (p = ctx->first_trees; p != ctx->trees; p = p->next) { + for (n = 0; n < 31; n++) + if (audit_tree_match(p->c[n], tree)) + return 1; + } + /* partial */ + if (p) { + for (n = ctx->tree_count; n < 31; n++) + if (audit_tree_match(p->c[n], tree)) + return 1; + } +#endif + return 0; +} + +static int audit_compare_uid(kuid_t uid, + struct audit_names *name, + struct audit_field *f, + struct audit_context *ctx) +{ + struct audit_names *n; + int rc; + + if (name) { + rc = audit_uid_comparator(uid, f->op, name->uid); + if (rc) + return rc; + } + + if (ctx) { + list_for_each_entry(n, &ctx->names_list, list) { + rc = audit_uid_comparator(uid, f->op, n->uid); + if (rc) + return rc; + } + } + return 0; +} + +static int audit_compare_gid(kgid_t gid, + struct audit_names *name, + struct audit_field *f, + struct audit_context *ctx) +{ + struct audit_names *n; + int rc; + + if (name) { + rc = audit_gid_comparator(gid, f->op, name->gid); + if (rc) + return rc; + } + + if (ctx) { + list_for_each_entry(n, &ctx->names_list, list) { + rc = audit_gid_comparator(gid, f->op, n->gid); + if (rc) + return rc; + } + } + return 0; +} + +static int audit_field_compare(struct task_struct *tsk, + const struct cred *cred, + struct audit_field *f, + struct audit_context *ctx, + struct audit_names *name) +{ + switch (f->val) { + /* process to file object comparisons */ + case AUDIT_COMPARE_UID_TO_OBJ_UID: + return audit_compare_uid(cred->uid, name, f, ctx); + case AUDIT_COMPARE_GID_TO_OBJ_GID: + return audit_compare_gid(cred->gid, name, f, ctx); + case AUDIT_COMPARE_EUID_TO_OBJ_UID: + return audit_compare_uid(cred->euid, name, f, ctx); + case AUDIT_COMPARE_EGID_TO_OBJ_GID: + return audit_compare_gid(cred->egid, name, f, ctx); + case AUDIT_COMPARE_AUID_TO_OBJ_UID: + return audit_compare_uid(tsk->loginuid, name, f, ctx); + case AUDIT_COMPARE_SUID_TO_OBJ_UID: + return audit_compare_uid(cred->suid, name, f, ctx); + case AUDIT_COMPARE_SGID_TO_OBJ_GID: + return audit_compare_gid(cred->sgid, name, f, ctx); + case AUDIT_COMPARE_FSUID_TO_OBJ_UID: + return audit_compare_uid(cred->fsuid, name, f, ctx); + case AUDIT_COMPARE_FSGID_TO_OBJ_GID: + return audit_compare_gid(cred->fsgid, name, f, ctx); + /* uid comparisons */ + case AUDIT_COMPARE_UID_TO_AUID: + return audit_uid_comparator(cred->uid, f->op, tsk->loginuid); + case AUDIT_COMPARE_UID_TO_EUID: + return audit_uid_comparator(cred->uid, f->op, cred->euid); + case AUDIT_COMPARE_UID_TO_SUID: + return audit_uid_comparator(cred->uid, f->op, cred->suid); + case AUDIT_COMPARE_UID_TO_FSUID: + return audit_uid_comparator(cred->uid, f->op, cred->fsuid); + /* auid comparisons */ + case AUDIT_COMPARE_AUID_TO_EUID: + return audit_uid_comparator(tsk->loginuid, f->op, cred->euid); + case AUDIT_COMPARE_AUID_TO_SUID: + return audit_uid_comparator(tsk->loginuid, f->op, cred->suid); + case AUDIT_COMPARE_AUID_TO_FSUID: + return audit_uid_comparator(tsk->loginuid, f->op, cred->fsuid); + /* euid comparisons */ + case AUDIT_COMPARE_EUID_TO_SUID: + return audit_uid_comparator(cred->euid, f->op, cred->suid); + case AUDIT_COMPARE_EUID_TO_FSUID: + return audit_uid_comparator(cred->euid, f->op, cred->fsuid); + /* suid comparisons */ + case AUDIT_COMPARE_SUID_TO_FSUID: + return audit_uid_comparator(cred->suid, f->op, cred->fsuid); + /* gid comparisons */ + case AUDIT_COMPARE_GID_TO_EGID: + return audit_gid_comparator(cred->gid, f->op, cred->egid); + case AUDIT_COMPARE_GID_TO_SGID: + return audit_gid_comparator(cred->gid, f->op, cred->sgid); + case AUDIT_COMPARE_GID_TO_FSGID: + return audit_gid_comparator(cred->gid, f->op, cred->fsgid); + /* egid comparisons */ + case AUDIT_COMPARE_EGID_TO_SGID: + return audit_gid_comparator(cred->egid, f->op, cred->sgid); + case AUDIT_COMPARE_EGID_TO_FSGID: + return audit_gid_comparator(cred->egid, f->op, cred->fsgid); + /* sgid comparison */ + case AUDIT_COMPARE_SGID_TO_FSGID: + return audit_gid_comparator(cred->sgid, f->op, cred->fsgid); + default: + WARN(1, "Missing AUDIT_COMPARE define. Report as a bug\n"); + return 0; + } + return 0; +} + +/* Determine if any context name data matches a rule's watch data */ +/* Compare a task_struct with an audit_rule. Return 1 on match, 0 + * otherwise. + * + * If task_creation is true, this is an explicit indication that we are + * filtering a task rule at task creation time. This and tsk == current are + * the only situations where tsk->cred may be accessed without an rcu read lock. + */ +static int audit_filter_rules(struct task_struct *tsk, + struct audit_krule *rule, + struct audit_context *ctx, + struct audit_names *name, + enum audit_state *state, + bool task_creation) +{ + const struct cred *cred; + int i, need_sid = 1; + u32 sid; + + cred = rcu_dereference_check(tsk->cred, tsk == current || task_creation); + + for (i = 0; i < rule->field_count; i++) { + struct audit_field *f = &rule->fields[i]; + struct audit_names *n; + int result = 0; + pid_t pid; + + switch (f->type) { + case AUDIT_PID: + pid = task_pid_nr(tsk); + result = audit_comparator(pid, f->op, f->val); + break; + case AUDIT_PPID: + if (ctx) { + if (!ctx->ppid) + ctx->ppid = task_ppid_nr(tsk); + result = audit_comparator(ctx->ppid, f->op, f->val); + } + break; + case AUDIT_UID: + result = audit_uid_comparator(cred->uid, f->op, f->uid); + break; + case AUDIT_EUID: + result = audit_uid_comparator(cred->euid, f->op, f->uid); + break; + case AUDIT_SUID: + result = audit_uid_comparator(cred->suid, f->op, f->uid); + break; + case AUDIT_FSUID: + result = audit_uid_comparator(cred->fsuid, f->op, f->uid); + break; + case AUDIT_GID: + result = audit_gid_comparator(cred->gid, f->op, f->gid); + if (f->op == Audit_equal) { + if (!result) + result = in_group_p(f->gid); + } else if (f->op == Audit_not_equal) { + if (result) + result = !in_group_p(f->gid); + } + break; + case AUDIT_EGID: + result = audit_gid_comparator(cred->egid, f->op, f->gid); + if (f->op == Audit_equal) { + if (!result) + result = in_egroup_p(f->gid); + } else if (f->op == Audit_not_equal) { + if (result) + result = !in_egroup_p(f->gid); + } + break; + case AUDIT_SGID: + result = audit_gid_comparator(cred->sgid, f->op, f->gid); + break; + case AUDIT_FSGID: + result = audit_gid_comparator(cred->fsgid, f->op, f->gid); + break; + case AUDIT_PERS: + result = audit_comparator(tsk->personality, f->op, f->val); + break; + case AUDIT_ARCH: + if (ctx) + result = audit_comparator(ctx->arch, f->op, f->val); + break; + + case AUDIT_EXIT: + if (ctx && ctx->return_valid) + result = audit_comparator(ctx->return_code, f->op, f->val); + break; + case AUDIT_SUCCESS: + if (ctx && ctx->return_valid) { + if (f->val) + result = audit_comparator(ctx->return_valid, f->op, AUDITSC_SUCCESS); + else + result = audit_comparator(ctx->return_valid, f->op, AUDITSC_FAILURE); + } + break; + case AUDIT_DEVMAJOR: + if (name) { + if (audit_comparator(MAJOR(name->dev), f->op, f->val) || + audit_comparator(MAJOR(name->rdev), f->op, f->val)) + ++result; + } else if (ctx) { + list_for_each_entry(n, &ctx->names_list, list) { + if (audit_comparator(MAJOR(n->dev), f->op, f->val) || + audit_comparator(MAJOR(n->rdev), f->op, f->val)) { + ++result; + break; + } + } + } + break; + case AUDIT_DEVMINOR: + if (name) { + if (audit_comparator(MINOR(name->dev), f->op, f->val) || + audit_comparator(MINOR(name->rdev), f->op, f->val)) + ++result; + } else if (ctx) { + list_for_each_entry(n, &ctx->names_list, list) { + if (audit_comparator(MINOR(n->dev), f->op, f->val) || + audit_comparator(MINOR(n->rdev), f->op, f->val)) { + ++result; + break; + } + } + } + break; + case AUDIT_INODE: + if (name) + result = audit_comparator(name->ino, f->op, f->val); + else if (ctx) { + list_for_each_entry(n, &ctx->names_list, list) { + if (audit_comparator(n->ino, f->op, f->val)) { + ++result; + break; + } + } + } + break; + case AUDIT_OBJ_UID: + if (name) { + result = audit_uid_comparator(name->uid, f->op, f->uid); + } else if (ctx) { + list_for_each_entry(n, &ctx->names_list, list) { + if (audit_uid_comparator(n->uid, f->op, f->uid)) { + ++result; + break; + } + } + } + break; + case AUDIT_OBJ_GID: + if (name) { + result = audit_gid_comparator(name->gid, f->op, f->gid); + } else if (ctx) { + list_for_each_entry(n, &ctx->names_list, list) { + if (audit_gid_comparator(n->gid, f->op, f->gid)) { + ++result; + break; + } + } + } + break; + case AUDIT_WATCH: + if (name) + result = audit_watch_compare(rule->watch, name->ino, name->dev); + break; + case AUDIT_DIR: + if (ctx) + result = match_tree_refs(ctx, rule->tree); + break; + case AUDIT_LOGINUID: + result = 0; + 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: + case AUDIT_SUBJ_SEN: + case AUDIT_SUBJ_CLR: + /* NOTE: this may return negative values indicating + a temporary error. We simply treat this as a + match for now to avoid losing information that + may be wanted. An error message will also be + logged upon error */ + if (f->lsm_rule) { + if (need_sid) { + security_task_getsecid(tsk, &sid); + need_sid = 0; + } + result = security_audit_rule_match(sid, f->type, + f->op, + f->lsm_rule, + ctx); + } + break; + case AUDIT_OBJ_USER: + case AUDIT_OBJ_ROLE: + case AUDIT_OBJ_TYPE: + case AUDIT_OBJ_LEV_LOW: + case AUDIT_OBJ_LEV_HIGH: + /* The above note for AUDIT_SUBJ_USER...AUDIT_SUBJ_CLR + also applies here */ + if (f->lsm_rule) { + /* Find files that match */ + if (name) { + result = security_audit_rule_match( + name->osid, f->type, f->op, + f->lsm_rule, ctx); + } else if (ctx) { + list_for_each_entry(n, &ctx->names_list, list) { + if (security_audit_rule_match(n->osid, f->type, + f->op, f->lsm_rule, + ctx)) { + ++result; + break; + } + } + } + /* Find ipc objects that match */ + if (!ctx || ctx->type != AUDIT_IPC) + break; + if (security_audit_rule_match(ctx->ipc.osid, + f->type, f->op, + f->lsm_rule, ctx)) + ++result; + } + break; + case AUDIT_ARG0: + case AUDIT_ARG1: + case AUDIT_ARG2: + case AUDIT_ARG3: + if (ctx) + result = audit_comparator(ctx->argv[f->type-AUDIT_ARG0], f->op, f->val); + break; + case AUDIT_FILTERKEY: + /* ignore this field for filtering */ + result = 1; + break; + case AUDIT_PERM: + result = audit_match_perm(ctx, f->val); + break; + case AUDIT_FILETYPE: + result = audit_match_filetype(ctx, f->val); + break; + case AUDIT_FIELD_COMPARE: + result = audit_field_compare(tsk, cred, f, ctx, name); + break; + } + if (!result) + return 0; + } + + if (ctx) { + if (rule->prio <= ctx->prio) + return 0; + if (rule->filterkey) { + kfree(ctx->filterkey); + ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC); + } + ctx->prio = rule->prio; + } + switch (rule->action) { + case AUDIT_NEVER: *state = AUDIT_DISABLED; break; + case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break; + } + return 1; +} + +/* At process creation time, we can determine if system-call auditing is + * completely disabled for this task. Since we only have the task + * structure at this point, we can only check uid and gid. + */ +static enum audit_state audit_filter_task(struct task_struct *tsk, char **key) +{ + struct audit_entry *e; + enum audit_state state; + + rcu_read_lock(); + list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TASK], list) { + if (audit_filter_rules(tsk, &e->rule, NULL, NULL, + &state, true)) { + if (state == AUDIT_RECORD_CONTEXT) + *key = kstrdup(e->rule.filterkey, GFP_ATOMIC); + rcu_read_unlock(); + return state; + } + } + rcu_read_unlock(); + return AUDIT_BUILD_CONTEXT; +} + +static int audit_in_mask(const struct audit_krule *rule, unsigned long val) +{ + int word, bit; + + if (val > 0xffffffff) + return false; + + word = AUDIT_WORD(val); + if (word >= AUDIT_BITMASK_SIZE) + return false; + + bit = AUDIT_BIT(val); + + return rule->mask[word] & bit; +} + +/* At syscall entry and exit time, this filter is called if the + * audit_state is not low enough that auditing cannot take place, but is + * also not high enough that we already know we have to write an audit + * record (i.e., the state is AUDIT_SETUP_CONTEXT or AUDIT_BUILD_CONTEXT). + */ +static enum audit_state audit_filter_syscall(struct task_struct *tsk, + struct audit_context *ctx, + struct list_head *list) +{ + struct audit_entry *e; + enum audit_state state; + + if (audit_pid && tsk->tgid == audit_pid) + return AUDIT_DISABLED; + + rcu_read_lock(); + if (!list_empty(list)) { + list_for_each_entry_rcu(e, list, list) { + if (audit_in_mask(&e->rule, ctx->major) && + audit_filter_rules(tsk, &e->rule, ctx, NULL, + &state, false)) { + rcu_read_unlock(); + ctx->current_state = state; + return state; + } + } + } + rcu_read_unlock(); + return AUDIT_BUILD_CONTEXT; +} + +/* + * Given an audit_name check the inode hash table to see if they match. + * Called holding the rcu read lock to protect the use of audit_inode_hash + */ +static int audit_filter_inode_name(struct task_struct *tsk, + struct audit_names *n, + struct audit_context *ctx) { + int h = audit_hash_ino((u32)n->ino); + struct list_head *list = &audit_inode_hash[h]; + struct audit_entry *e; + enum audit_state state; + + if (list_empty(list)) + return 0; + + list_for_each_entry_rcu(e, list, list) { + if (audit_in_mask(&e->rule, ctx->major) && + audit_filter_rules(tsk, &e->rule, ctx, n, &state, false)) { + ctx->current_state = state; + return 1; + } + } + + return 0; +} + +/* At syscall exit time, this filter is called if any audit_names have been + * collected during syscall processing. We only check rules in sublists at hash + * buckets applicable to the inode numbers in audit_names. + * Regarding audit_state, same rules apply as for audit_filter_syscall(). + */ +void audit_filter_inodes(struct task_struct *tsk, struct audit_context *ctx) +{ + struct audit_names *n; + + if (audit_pid && tsk->tgid == audit_pid) + return; + + rcu_read_lock(); + + list_for_each_entry(n, &ctx->names_list, list) { + if (audit_filter_inode_name(tsk, n, ctx)) + break; + } + rcu_read_unlock(); +} + +/* Transfer the audit context pointer to the caller, clearing it in the tsk's struct */ +static inline struct audit_context *audit_take_context(struct task_struct *tsk, + int return_valid, + long return_code) +{ + struct audit_context *context = tsk->audit_context; + + if (!context) + return NULL; + context->return_valid = return_valid; + + /* + * we need to fix up the return code in the audit logs if the actual + * return codes are later going to be fixed up by the arch specific + * signal handlers + * + * This is actually a test for: + * (rc == ERESTARTSYS ) || (rc == ERESTARTNOINTR) || + * (rc == ERESTARTNOHAND) || (rc == ERESTART_RESTARTBLOCK) + * + * but is faster than a bunch of || + */ + if (unlikely(return_code <= -ERESTARTSYS) && + (return_code >= -ERESTART_RESTARTBLOCK) && + (return_code != -ENOIOCTLCMD)) + context->return_code = -EINTR; + else + context->return_code = return_code; + + if (context->in_syscall && !context->dummy) { + audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]); + audit_filter_inodes(tsk, context); + } + + tsk->audit_context = NULL; + return context; +} + +static inline void audit_proctitle_free(struct audit_context *context) +{ + kfree(context->proctitle.value); + context->proctitle.value = NULL; + context->proctitle.len = 0; +} + +static inline void audit_free_names(struct audit_context *context) +{ + struct audit_names *n, *next; + + list_for_each_entry_safe(n, next, &context->names_list, list) { + list_del(&n->list); + if (n->name) + putname(n->name); + if (n->should_free) + kfree(n); + } + context->name_count = 0; + path_put(&context->pwd); + context->pwd.dentry = NULL; + context->pwd.mnt = NULL; +} + +static inline void audit_free_aux(struct audit_context *context) +{ + struct audit_aux_data *aux; + + while ((aux = context->aux)) { + context->aux = aux->next; + kfree(aux); + } + while ((aux = context->aux_pids)) { + context->aux_pids = aux->next; + kfree(aux); + } +} + +static inline struct audit_context *audit_alloc_context(enum audit_state state) +{ + struct audit_context *context; + + context = kzalloc(sizeof(*context), GFP_KERNEL); + if (!context) + return NULL; + context->state = state; + context->prio = state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0; + INIT_LIST_HEAD(&context->killed_trees); + INIT_LIST_HEAD(&context->names_list); + return context; +} + +/** + * audit_alloc - allocate an audit context block for a task + * @tsk: task + * + * Filter on the task information and allocate a per-task audit context + * if necessary. Doing so turns on system call auditing for the + * specified task. This is called from copy_process, so no lock is + * needed. + */ +int audit_alloc(struct task_struct *tsk) +{ + struct audit_context *context; + enum audit_state state; + char *key = NULL; + + if (likely(!audit_ever_enabled)) + return 0; /* Return if not auditing. */ + + state = audit_filter_task(tsk, &key); + if (state == AUDIT_DISABLED) { + clear_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT); + return 0; + } + + if (!(context = audit_alloc_context(state))) { + kfree(key); + audit_log_lost("out of memory in audit_alloc"); + return -ENOMEM; + } + context->filterkey = key; + + tsk->audit_context = context; + set_tsk_thread_flag(tsk, TIF_SYSCALL_AUDIT); + return 0; +} + +static inline void audit_free_context(struct audit_context *context) +{ + audit_free_names(context); + unroll_tree_refs(context, NULL, 0); + free_tree_refs(context); + audit_free_aux(context); + kfree(context->filterkey); + kfree(context->sockaddr); + audit_proctitle_free(context); + kfree(context); +} + +static int audit_log_pid_context(struct audit_context *context, pid_t pid, + kuid_t auid, kuid_t uid, unsigned int sessionid, + u32 sid, char *comm) +{ + struct audit_buffer *ab; + char *ctx = NULL; + u32 len; + int rc = 0; + + ab = audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID); + if (!ab) + return rc; + + audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid, + from_kuid(&init_user_ns, auid), + from_kuid(&init_user_ns, uid), sessionid); + if (sid) { + if (security_secid_to_secctx(sid, &ctx, &len)) { + audit_log_format(ab, " obj=(none)"); + rc = 1; + } else { + audit_log_format(ab, " obj=%s", ctx); + security_release_secctx(ctx, len); + } + } + audit_log_format(ab, " ocomm="); + audit_log_untrustedstring(ab, comm); + audit_log_end(ab); + + return rc; +} + +/* + * to_send and len_sent accounting are very loose estimates. We aren't + * really worried about a hard cap to MAX_EXECVE_AUDIT_LEN so much as being + * within about 500 bytes (next page boundary) + * + * why snprintf? an int is up to 12 digits long. if we just assumed when + * logging that a[%d]= was going to be 16 characters long we would be wasting + * space in every audit message. In one 7500 byte message we can log up to + * about 1000 min size arguments. That comes down to about 50% waste of space + * if we didn't do the snprintf to find out how long arg_num_len was. + */ +static int audit_log_single_execve_arg(struct audit_context *context, + struct audit_buffer **ab, + int arg_num, + size_t *len_sent, + const char __user *p, + char *buf) +{ + char arg_num_len_buf[12]; + const char __user *tmp_p = p; + /* how many digits are in arg_num? 5 is the length of ' a=""' */ + size_t arg_num_len = snprintf(arg_num_len_buf, 12, "%d", arg_num) + 5; + size_t len, len_left, to_send; + size_t max_execve_audit_len = MAX_EXECVE_AUDIT_LEN; + unsigned int i, has_cntl = 0, too_long = 0; + int ret; + + /* strnlen_user includes the null we don't want to send */ + len_left = len = strnlen_user(p, MAX_ARG_STRLEN) - 1; + + /* + * We just created this mm, if we can't find the strings + * we just copied into it something is _very_ wrong. Similar + * for strings that are too long, we should not have created + * any. + */ + if (unlikely((len == -1) || len > MAX_ARG_STRLEN - 1)) { + WARN_ON(1); + send_sig(SIGKILL, current, 0); + return -1; + } + + /* walk the whole argument looking for non-ascii chars */ + do { + if (len_left > MAX_EXECVE_AUDIT_LEN) + to_send = MAX_EXECVE_AUDIT_LEN; + else + to_send = len_left; + ret = copy_from_user(buf, tmp_p, to_send); + /* + * There is no reason for this copy to be short. We just + * copied them here, and the mm hasn't been exposed to user- + * space yet. + */ + if (ret) { + WARN_ON(1); + send_sig(SIGKILL, current, 0); + return -1; + } + buf[to_send] = '\0'; + has_cntl = audit_string_contains_control(buf, to_send); + if (has_cntl) { + /* + * hex messages get logged as 2 bytes, so we can only + * send half as much in each message + */ + max_execve_audit_len = MAX_EXECVE_AUDIT_LEN / 2; + break; + } + len_left -= to_send; + tmp_p += to_send; + } while (len_left > 0); + + len_left = len; + + if (len > max_execve_audit_len) + too_long = 1; + + /* rewalk the argument actually logging the message */ + for (i = 0; len_left > 0; i++) { + int room_left; + + if (len_left > max_execve_audit_len) + to_send = max_execve_audit_len; + else + to_send = len_left; + + /* do we have space left to send this argument in this ab? */ + room_left = MAX_EXECVE_AUDIT_LEN - arg_num_len - *len_sent; + if (has_cntl) + room_left -= (to_send * 2); + else + room_left -= to_send; + if (room_left < 0) { + *len_sent = 0; + audit_log_end(*ab); + *ab = audit_log_start(context, GFP_KERNEL, AUDIT_EXECVE); + if (!*ab) + return 0; + } + + /* + * first record needs to say how long the original string was + * so we can be sure nothing was lost. + */ + if ((i == 0) && (too_long)) + audit_log_format(*ab, " a%d_len=%zu", arg_num, + has_cntl ? 2*len : len); + + /* + * normally arguments are small enough to fit and we already + * filled buf above when we checked for control characters + * so don't bother with another copy_from_user + */ + if (len >= max_execve_audit_len) + ret = copy_from_user(buf, p, to_send); + else + ret = 0; + if (ret) { + WARN_ON(1); + send_sig(SIGKILL, current, 0); + return -1; + } + buf[to_send] = '\0'; + + /* actually log it */ + audit_log_format(*ab, " a%d", arg_num); + if (too_long) + audit_log_format(*ab, "[%d]", i); + audit_log_format(*ab, "="); + if (has_cntl) + audit_log_n_hex(*ab, buf, to_send); + else + audit_log_string(*ab, buf); + + p += to_send; + len_left -= to_send; + *len_sent += arg_num_len; + if (has_cntl) + *len_sent += to_send * 2; + else + *len_sent += to_send; + } + /* include the null we didn't log */ + return len + 1; +} + +static void audit_log_execve_info(struct audit_context *context, + struct audit_buffer **ab) +{ + int i, len; + size_t len_sent = 0; + const char __user *p; + char *buf; + + p = (const char __user *)current->mm->arg_start; + + audit_log_format(*ab, "argc=%d", context->execve.argc); + + /* + * we need some kernel buffer to hold the userspace args. Just + * allocate one big one rather than allocating one of the right size + * for every single argument inside audit_log_single_execve_arg() + * should be <8k allocation so should be pretty safe. + */ + buf = kmalloc(MAX_EXECVE_AUDIT_LEN + 1, GFP_KERNEL); + if (!buf) { + audit_panic("out of memory for argv string"); + return; + } + + for (i = 0; i < context->execve.argc; i++) { + len = audit_log_single_execve_arg(context, ab, i, + &len_sent, p, buf); + if (len <= 0) + break; + p += len; + } + kfree(buf); +} + +static void show_special(struct audit_context *context, int *call_panic) +{ + struct audit_buffer *ab; + int i; + + ab = audit_log_start(context, GFP_KERNEL, context->type); + if (!ab) + return; + + switch (context->type) { + case AUDIT_SOCKETCALL: { + int nargs = context->socketcall.nargs; + audit_log_format(ab, "nargs=%d", nargs); + for (i = 0; i < nargs; i++) + audit_log_format(ab, " a%d=%lx", i, + context->socketcall.args[i]); + break; } + case AUDIT_IPC: { + u32 osid = context->ipc.osid; + + audit_log_format(ab, "ouid=%u ogid=%u mode=%#ho", + from_kuid(&init_user_ns, context->ipc.uid), + from_kgid(&init_user_ns, context->ipc.gid), + context->ipc.mode); + if (osid) { + char *ctx = NULL; + u32 len; + if (security_secid_to_secctx(osid, &ctx, &len)) { + audit_log_format(ab, " osid=%u", osid); + *call_panic = 1; + } else { + audit_log_format(ab, " obj=%s", ctx); + security_release_secctx(ctx, len); + } + } + if (context->ipc.has_perm) { + audit_log_end(ab); + ab = audit_log_start(context, GFP_KERNEL, + AUDIT_IPC_SET_PERM); + if (unlikely(!ab)) + return; + audit_log_format(ab, + "qbytes=%lx ouid=%u ogid=%u mode=%#ho", + context->ipc.qbytes, + context->ipc.perm_uid, + context->ipc.perm_gid, + context->ipc.perm_mode); + } + break; } + case AUDIT_MQ_OPEN: { + audit_log_format(ab, + "oflag=0x%x mode=%#ho mq_flags=0x%lx mq_maxmsg=%ld " + "mq_msgsize=%ld mq_curmsgs=%ld", + context->mq_open.oflag, context->mq_open.mode, + context->mq_open.attr.mq_flags, + context->mq_open.attr.mq_maxmsg, + context->mq_open.attr.mq_msgsize, + context->mq_open.attr.mq_curmsgs); + break; } + case AUDIT_MQ_SENDRECV: { + audit_log_format(ab, + "mqdes=%d msg_len=%zd msg_prio=%u " + "abs_timeout_sec=%ld abs_timeout_nsec=%ld", + context->mq_sendrecv.mqdes, + context->mq_sendrecv.msg_len, + context->mq_sendrecv.msg_prio, + context->mq_sendrecv.abs_timeout.tv_sec, + context->mq_sendrecv.abs_timeout.tv_nsec); + break; } + case AUDIT_MQ_NOTIFY: { + audit_log_format(ab, "mqdes=%d sigev_signo=%d", + context->mq_notify.mqdes, + context->mq_notify.sigev_signo); + break; } + case AUDIT_MQ_GETSETATTR: { + struct mq_attr *attr = &context->mq_getsetattr.mqstat; + audit_log_format(ab, + "mqdes=%d mq_flags=0x%lx mq_maxmsg=%ld mq_msgsize=%ld " + "mq_curmsgs=%ld ", + context->mq_getsetattr.mqdes, + attr->mq_flags, attr->mq_maxmsg, + attr->mq_msgsize, attr->mq_curmsgs); + break; } + case AUDIT_CAPSET: { + audit_log_format(ab, "pid=%d", context->capset.pid); + audit_log_cap(ab, "cap_pi", &context->capset.cap.inheritable); + audit_log_cap(ab, "cap_pp", &context->capset.cap.permitted); + audit_log_cap(ab, "cap_pe", &context->capset.cap.effective); + break; } + case AUDIT_MMAP: { + audit_log_format(ab, "fd=%d flags=0x%x", context->mmap.fd, + context->mmap.flags); + break; } + case AUDIT_EXECVE: { + audit_log_execve_info(context, &ab); + break; } + } + audit_log_end(ab); +} + +static inline int audit_proctitle_rtrim(char *proctitle, int len) +{ + char *end = proctitle + len - 1; + while (end > proctitle && !isprint(*end)) + end--; + + /* catch the case where proctitle is only 1 non-print character */ + len = end - proctitle + 1; + len -= isprint(proctitle[len-1]) == 0; + return len; +} + +static void audit_log_proctitle(struct task_struct *tsk, + struct audit_context *context) +{ + int res; + char *buf; + char *msg = "(null)"; + int len = strlen(msg); + struct audit_buffer *ab; + + ab = audit_log_start(context, GFP_KERNEL, AUDIT_PROCTITLE); + if (!ab) + return; /* audit_panic or being filtered */ + + audit_log_format(ab, "proctitle="); + + /* Not cached */ + if (!context->proctitle.value) { + buf = kmalloc(MAX_PROCTITLE_AUDIT_LEN, GFP_KERNEL); + if (!buf) + goto out; + /* Historically called this from procfs naming */ + res = get_cmdline(tsk, buf, MAX_PROCTITLE_AUDIT_LEN); + if (res == 0) { + kfree(buf); + goto out; + } + res = audit_proctitle_rtrim(buf, res); + if (res == 0) { + kfree(buf); + goto out; + } + context->proctitle.value = buf; + context->proctitle.len = res; + } + msg = context->proctitle.value; + len = context->proctitle.len; +out: + audit_log_n_untrustedstring(ab, msg, len); + audit_log_end(ab); +} + +static void audit_log_exit(struct audit_context *context, struct task_struct *tsk) +{ + int i, call_panic = 0; + struct audit_buffer *ab; + struct audit_aux_data *aux; + struct audit_names *n; + + /* tsk == current */ + context->personality = tsk->personality; + + ab = audit_log_start(context, GFP_KERNEL, AUDIT_SYSCALL); + if (!ab) + return; /* audit_panic has been called */ + audit_log_format(ab, "arch=%x syscall=%d", + context->arch, context->major); + if (context->personality != PER_LINUX) + audit_log_format(ab, " per=%lx", context->personality); + if (context->return_valid) + audit_log_format(ab, " success=%s exit=%ld", + (context->return_valid==AUDITSC_SUCCESS)?"yes":"no", + context->return_code); + + audit_log_format(ab, + " a0=%lx a1=%lx a2=%lx a3=%lx items=%d", + context->argv[0], + context->argv[1], + context->argv[2], + context->argv[3], + context->name_count); + + audit_log_task_info(ab, tsk); + audit_log_key(ab, context->filterkey); + audit_log_end(ab); + + for (aux = context->aux; aux; aux = aux->next) { + + ab = audit_log_start(context, GFP_KERNEL, aux->type); + if (!ab) + continue; /* audit_panic has been called */ + + switch (aux->type) { + + case AUDIT_BPRM_FCAPS: { + struct audit_aux_data_bprm_fcaps *axs = (void *)aux; + audit_log_format(ab, "fver=%x", axs->fcap_ver); + audit_log_cap(ab, "fp", &axs->fcap.permitted); + audit_log_cap(ab, "fi", &axs->fcap.inheritable); + audit_log_format(ab, " fe=%d", axs->fcap.fE); + audit_log_cap(ab, "old_pp", &axs->old_pcap.permitted); + audit_log_cap(ab, "old_pi", &axs->old_pcap.inheritable); + audit_log_cap(ab, "old_pe", &axs->old_pcap.effective); + audit_log_cap(ab, "new_pp", &axs->new_pcap.permitted); + audit_log_cap(ab, "new_pi", &axs->new_pcap.inheritable); + audit_log_cap(ab, "new_pe", &axs->new_pcap.effective); + break; } + + } + audit_log_end(ab); + } + + if (context->type) + show_special(context, &call_panic); + + if (context->fds[0] >= 0) { + ab = audit_log_start(context, GFP_KERNEL, AUDIT_FD_PAIR); + if (ab) { + audit_log_format(ab, "fd0=%d fd1=%d", + context->fds[0], context->fds[1]); + audit_log_end(ab); + } + } + + if (context->sockaddr_len) { + ab = audit_log_start(context, GFP_KERNEL, AUDIT_SOCKADDR); + if (ab) { + audit_log_format(ab, "saddr="); + audit_log_n_hex(ab, (void *)context->sockaddr, + context->sockaddr_len); + audit_log_end(ab); + } + } + + for (aux = context->aux_pids; aux; aux = aux->next) { + struct audit_aux_data_pids *axs = (void *)aux; + + for (i = 0; i < axs->pid_count; i++) + if (audit_log_pid_context(context, axs->target_pid[i], + axs->target_auid[i], + axs->target_uid[i], + axs->target_sessionid[i], + axs->target_sid[i], + axs->target_comm[i])) + call_panic = 1; + } + + if (context->target_pid && + audit_log_pid_context(context, context->target_pid, + context->target_auid, context->target_uid, + context->target_sessionid, + context->target_sid, context->target_comm)) + call_panic = 1; + + if (context->pwd.dentry && context->pwd.mnt) { + ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD); + if (ab) { + audit_log_d_path(ab, " cwd=", &context->pwd); + audit_log_end(ab); + } + } + + i = 0; + list_for_each_entry(n, &context->names_list, list) { + if (n->hidden) + continue; + audit_log_name(context, n, NULL, i++, &call_panic); + } + + audit_log_proctitle(tsk, context); + + /* Send end of event record to help user space know we are finished */ + ab = audit_log_start(context, GFP_KERNEL, AUDIT_EOE); + if (ab) + audit_log_end(ab); + if (call_panic) + audit_panic("error converting sid to string"); +} + +/** + * audit_free - free a per-task audit context + * @tsk: task whose audit context block to free + * + * Called from copy_process and do_exit + */ +void __audit_free(struct task_struct *tsk) +{ + struct audit_context *context; + + context = audit_take_context(tsk, 0, 0); + if (!context) + return; + + /* Check for system calls that do not go through the exit + * function (e.g., exit_group), then free context block. + * We use GFP_ATOMIC here because we might be doing this + * in the context of the idle thread */ + /* that can happen only if we are called from do_exit() */ + if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT) + audit_log_exit(context, tsk); + if (!list_empty(&context->killed_trees)) + audit_kill_trees(&context->killed_trees); + + audit_free_context(context); +} + +/** + * audit_syscall_entry - fill in an audit record at syscall entry + * @major: major syscall type (function) + * @a1: additional syscall register 1 + * @a2: additional syscall register 2 + * @a3: additional syscall register 3 + * @a4: additional syscall register 4 + * + * Fill in audit context at syscall entry. This only happens if the + * audit context was created when the task was created and the state or + * filters demand the audit context be built. If the state from the + * per-task filter or from the per-syscall filter is AUDIT_RECORD_CONTEXT, + * then the record will be written at syscall exit time (otherwise, it + * will only be written if another part of the kernel requests that it + * be written). + */ +void __audit_syscall_entry(int major, unsigned long a1, unsigned long a2, + unsigned long a3, unsigned long a4) +{ + struct task_struct *tsk = current; + struct audit_context *context = tsk->audit_context; + enum audit_state state; + + if (!context) + return; + + BUG_ON(context->in_syscall || context->name_count); + + if (!audit_enabled) + return; + + context->arch = syscall_get_arch(); + context->major = major; + context->argv[0] = a1; + context->argv[1] = a2; + context->argv[2] = a3; + context->argv[3] = a4; + + state = context->state; + context->dummy = !audit_n_rules; + if (!context->dummy && state == AUDIT_BUILD_CONTEXT) { + context->prio = 0; + state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_ENTRY]); + } + if (state == AUDIT_DISABLED) + return; + + context->serial = 0; + context->ctime = CURRENT_TIME; + context->in_syscall = 1; + context->current_state = state; + context->ppid = 0; +} + +/** + * audit_syscall_exit - deallocate audit context after a system call + * @success: success value of the syscall + * @return_code: return value of the syscall + * + * Tear down after system call. If the audit context has been marked as + * auditable (either because of the AUDIT_RECORD_CONTEXT state from + * filtering, or because some other part of the kernel wrote an audit + * message), then write out the syscall information. In call cases, + * free the names stored from getname(). + */ +void __audit_syscall_exit(int success, long return_code) +{ + struct task_struct *tsk = current; + struct audit_context *context; + + if (success) + success = AUDITSC_SUCCESS; + else + success = AUDITSC_FAILURE; + + context = audit_take_context(tsk, success, return_code); + if (!context) + return; + + if (context->in_syscall && context->current_state == AUDIT_RECORD_CONTEXT) + audit_log_exit(context, tsk); + + context->in_syscall = 0; + context->prio = context->state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0; + + if (!list_empty(&context->killed_trees)) + audit_kill_trees(&context->killed_trees); + + audit_free_names(context); + unroll_tree_refs(context, NULL, 0); + audit_free_aux(context); + context->aux = NULL; + context->aux_pids = NULL; + context->target_pid = 0; + context->target_sid = 0; + context->sockaddr_len = 0; + context->type = 0; + context->fds[0] = -1; + if (context->state != AUDIT_RECORD_CONTEXT) { + kfree(context->filterkey); + context->filterkey = NULL; + } + tsk->audit_context = context; +} + +static inline void handle_one(const struct inode *inode) +{ +#ifdef CONFIG_AUDIT_TREE + struct audit_context *context; + struct audit_tree_refs *p; + struct audit_chunk *chunk; + int count; + if (likely(hlist_empty(&inode->i_fsnotify_marks))) + return; + context = current->audit_context; + p = context->trees; + count = context->tree_count; + rcu_read_lock(); + chunk = audit_tree_lookup(inode); + rcu_read_unlock(); + if (!chunk) + return; + if (likely(put_tree_ref(context, chunk))) + return; + if (unlikely(!grow_tree_refs(context))) { + pr_warn("out of memory, audit has lost a tree reference\n"); + audit_set_auditable(context); + audit_put_chunk(chunk); + unroll_tree_refs(context, p, count); + return; + } + put_tree_ref(context, chunk); +#endif +} + +static void handle_path(const struct dentry *dentry) +{ +#ifdef CONFIG_AUDIT_TREE + struct audit_context *context; + struct audit_tree_refs *p; + const struct dentry *d, *parent; + struct audit_chunk *drop; + unsigned long seq; + int count; + + context = current->audit_context; + p = context->trees; + count = context->tree_count; +retry: + drop = NULL; + d = dentry; + rcu_read_lock(); + seq = read_seqbegin(&rename_lock); + for(;;) { + struct inode *inode = d_backing_inode(d); + if (inode && unlikely(!hlist_empty(&inode->i_fsnotify_marks))) { + struct audit_chunk *chunk; + chunk = audit_tree_lookup(inode); + if (chunk) { + if (unlikely(!put_tree_ref(context, chunk))) { + drop = chunk; + break; + } + } + } + parent = d->d_parent; + if (parent == d) + break; + d = parent; + } + if (unlikely(read_seqretry(&rename_lock, seq) || drop)) { /* in this order */ + rcu_read_unlock(); + if (!drop) { + /* just a race with rename */ + unroll_tree_refs(context, p, count); + goto retry; + } + audit_put_chunk(drop); + if (grow_tree_refs(context)) { + /* OK, got more space */ + unroll_tree_refs(context, p, count); + goto retry; + } + /* too bad */ + pr_warn("out of memory, audit has lost a tree reference\n"); + unroll_tree_refs(context, p, count); + audit_set_auditable(context); + return; + } + rcu_read_unlock(); +#endif +} + +static struct audit_names *audit_alloc_name(struct audit_context *context, + unsigned char type) +{ + struct audit_names *aname; + + if (context->name_count < AUDIT_NAMES) { + aname = &context->preallocated_names[context->name_count]; + memset(aname, 0, sizeof(*aname)); + } else { + aname = kzalloc(sizeof(*aname), GFP_NOFS); + if (!aname) + return NULL; + aname->should_free = true; + } + + aname->ino = (unsigned long)-1; + aname->type = type; + list_add_tail(&aname->list, &context->names_list); + + context->name_count++; + return aname; +} + +/** + * audit_reusename - fill out filename with info from existing entry + * @uptr: userland ptr to pathname + * + * Search the audit_names list for the current audit context. If there is an + * existing entry with a matching "uptr" then return the filename + * associated with that audit_name. If not, return NULL. + */ +struct filename * +__audit_reusename(const __user char *uptr) +{ + struct audit_context *context = current->audit_context; + struct audit_names *n; + + list_for_each_entry(n, &context->names_list, list) { + if (!n->name) + continue; + if (n->name->uptr == uptr) { + n->name->refcnt++; + return n->name; + } + } + return NULL; +} + +/** + * audit_getname - add a name to the list + * @name: name to add + * + * Add a name to the list of audit names for this context. + * Called from fs/namei.c:getname(). + */ +void __audit_getname(struct filename *name) +{ + struct audit_context *context = current->audit_context; + struct audit_names *n; + + if (!context->in_syscall) + return; + + n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN); + if (!n) + return; + + n->name = name; + n->name_len = AUDIT_NAME_FULL; + name->aname = n; + name->refcnt++; + + if (!context->pwd.dentry) + get_fs_pwd(current->fs, &context->pwd); +} + +/** + * __audit_inode - store the inode and device from a lookup + * @name: name being audited + * @dentry: dentry being audited + * @flags: attributes for this particular entry + */ +void __audit_inode(struct filename *name, const struct dentry *dentry, + unsigned int flags) +{ + struct audit_context *context = current->audit_context; + const struct inode *inode = d_backing_inode(dentry); + struct audit_names *n; + bool parent = flags & AUDIT_INODE_PARENT; + + if (!context->in_syscall) + return; + + if (!name) + goto out_alloc; + + /* + * If we have a pointer to an audit_names entry already, then we can + * just use it directly if the type is correct. + */ + n = name->aname; + if (n) { + if (parent) { + if (n->type == AUDIT_TYPE_PARENT || + n->type == AUDIT_TYPE_UNKNOWN) + goto out; + } else { + if (n->type != AUDIT_TYPE_PARENT) + goto out; + } + } + + list_for_each_entry_reverse(n, &context->names_list, list) { + if (n->ino) { + /* valid inode number, use that for the comparison */ + if (n->ino != inode->i_ino || + n->dev != inode->i_sb->s_dev) + continue; + } else if (n->name) { + /* inode number has not been set, check the name */ + if (strcmp(n->name->name, name->name)) + continue; + } else + /* no inode and no name (?!) ... this is odd ... */ + continue; + + /* match the correct record type */ + if (parent) { + if (n->type == AUDIT_TYPE_PARENT || + n->type == AUDIT_TYPE_UNKNOWN) + goto out; + } else { + if (n->type != AUDIT_TYPE_PARENT) + goto out; + } + } + +out_alloc: + /* unable to find an entry with both a matching name and type */ + n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN); + if (!n) + return; + if (name) { + n->name = name; + name->refcnt++; + } + +out: + if (parent) { + n->name_len = n->name ? parent_len(n->name->name) : AUDIT_NAME_FULL; + n->type = AUDIT_TYPE_PARENT; + if (flags & AUDIT_INODE_HIDDEN) + n->hidden = true; + } else { + n->name_len = AUDIT_NAME_FULL; + n->type = AUDIT_TYPE_NORMAL; + } + handle_path(dentry); + audit_copy_inode(n, dentry, inode); +} + +void __audit_file(const struct file *file) +{ + __audit_inode(NULL, file->f_path.dentry, 0); +} + +/** + * __audit_inode_child - collect inode info for created/removed objects + * @parent: inode of dentry parent + * @dentry: dentry being audited + * @type: AUDIT_TYPE_* value that we're looking for + * + * For syscalls that create or remove filesystem objects, audit_inode + * can only collect information for the filesystem object's parent. + * This call updates the audit context with the child's information. + * Syscalls that create a new filesystem object must be hooked after + * the object is created. Syscalls that remove a filesystem object + * must be hooked prior, in order to capture the target inode during + * unsuccessful attempts. + */ +void __audit_inode_child(const struct inode *parent, + const struct dentry *dentry, + const unsigned char type) +{ + struct audit_context *context = current->audit_context; + const struct inode *inode = d_backing_inode(dentry); + const char *dname = dentry->d_name.name; + struct audit_names *n, *found_parent = NULL, *found_child = NULL; + + if (!context->in_syscall) + return; + + if (inode) + handle_one(inode); + + /* look for a parent entry first */ + list_for_each_entry(n, &context->names_list, list) { + if (!n->name || + (n->type != AUDIT_TYPE_PARENT && + n->type != AUDIT_TYPE_UNKNOWN)) + continue; + + if (n->ino == parent->i_ino && n->dev == parent->i_sb->s_dev && + !audit_compare_dname_path(dname, + n->name->name, n->name_len)) { + if (n->type == AUDIT_TYPE_UNKNOWN) + n->type = AUDIT_TYPE_PARENT; + found_parent = n; + break; + } + } + + /* is there a matching child entry? */ + list_for_each_entry(n, &context->names_list, list) { + /* can only match entries that have a name */ + if (!n->name || + (n->type != type && n->type != AUDIT_TYPE_UNKNOWN)) + continue; + + if (!strcmp(dname, n->name->name) || + !audit_compare_dname_path(dname, n->name->name, + found_parent ? + found_parent->name_len : + AUDIT_NAME_FULL)) { + if (n->type == AUDIT_TYPE_UNKNOWN) + n->type = type; + found_child = n; + break; + } + } + + if (!found_parent) { + /* create a new, "anonymous" parent record */ + n = audit_alloc_name(context, AUDIT_TYPE_PARENT); + if (!n) + return; + audit_copy_inode(n, NULL, parent); + } + + if (!found_child) { + found_child = audit_alloc_name(context, type); + if (!found_child) + return; + + /* Re-use the name belonging to the slot for a matching parent + * directory. All names for this context are relinquished in + * audit_free_names() */ + if (found_parent) { + found_child->name = found_parent->name; + found_child->name_len = AUDIT_NAME_FULL; + found_child->name->refcnt++; + } + } + + if (inode) + audit_copy_inode(found_child, dentry, inode); + else + found_child->ino = (unsigned long)-1; +} +EXPORT_SYMBOL_GPL(__audit_inode_child); + +/** + * auditsc_get_stamp - get local copies of audit_context values + * @ctx: audit_context for the task + * @t: timespec to store time recorded in the audit_context + * @serial: serial value that is recorded in the audit_context + * + * Also sets the context as auditable. + */ +int auditsc_get_stamp(struct audit_context *ctx, + struct timespec *t, unsigned int *serial) +{ + if (!ctx->in_syscall) + return 0; + if (!ctx->serial) + ctx->serial = audit_serial(); + t->tv_sec = ctx->ctime.tv_sec; + t->tv_nsec = ctx->ctime.tv_nsec; + *serial = ctx->serial; + if (!ctx->prio) { + ctx->prio = 1; + ctx->current_state = AUDIT_RECORD_CONTEXT; + } + return 1; +} + +/* global counter which is incremented every time something logs in */ +static atomic_t session_id = ATOMIC_INIT(0); + +static int audit_set_loginuid_perm(kuid_t loginuid) +{ + /* if we are unset, we don't need privs */ + if (!audit_loginuid_set(current)) + return 0; + /* if AUDIT_FEATURE_LOGINUID_IMMUTABLE means never ever allow a change*/ + if (is_audit_feature_set(AUDIT_FEATURE_LOGINUID_IMMUTABLE)) + return -EPERM; + /* it is set, you need permission */ + if (!capable(CAP_AUDIT_CONTROL)) + return -EPERM; + /* reject if this is not an unset and we don't allow that */ + if (is_audit_feature_set(AUDIT_FEATURE_ONLY_UNSET_LOGINUID) && uid_valid(loginuid)) + return -EPERM; + return 0; +} + +static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid, + unsigned int oldsessionid, unsigned int sessionid, + int rc) +{ + struct audit_buffer *ab; + uid_t uid, oldloginuid, loginuid; + + if (!audit_enabled) + return; + + uid = from_kuid(&init_user_ns, task_uid(current)); + oldloginuid = from_kuid(&init_user_ns, koldloginuid); + loginuid = from_kuid(&init_user_ns, kloginuid), + + ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN); + if (!ab) + return; + audit_log_format(ab, "pid=%d uid=%u", task_pid_nr(current), uid); + audit_log_task_context(ab); + audit_log_format(ab, " old-auid=%u auid=%u old-ses=%u ses=%u res=%d", + oldloginuid, loginuid, oldsessionid, sessionid, !rc); + audit_log_end(ab); +} + +/** + * audit_set_loginuid - set current task's audit_context loginuid + * @loginuid: loginuid value + * + * Returns 0. + * + * Called (set) from fs/proc/base.c::proc_loginuid_write(). + */ +int audit_set_loginuid(kuid_t loginuid) +{ + struct task_struct *task = current; + unsigned int oldsessionid, sessionid = (unsigned int)-1; + kuid_t oldloginuid; + int rc; + + oldloginuid = audit_get_loginuid(current); + oldsessionid = audit_get_sessionid(current); + + rc = audit_set_loginuid_perm(loginuid); + if (rc) + goto out; + + /* are we setting or clearing? */ + if (uid_valid(loginuid)) + sessionid = (unsigned int)atomic_inc_return(&session_id); + + task->sessionid = sessionid; + task->loginuid = loginuid; +out: + audit_log_set_loginuid(oldloginuid, loginuid, oldsessionid, sessionid, rc); + return rc; +} + +/** + * __audit_mq_open - record audit data for a POSIX MQ open + * @oflag: open flag + * @mode: mode bits + * @attr: queue attributes + * + */ +void __audit_mq_open(int oflag, umode_t mode, struct mq_attr *attr) +{ + struct audit_context *context = current->audit_context; + + if (attr) + memcpy(&context->mq_open.attr, attr, sizeof(struct mq_attr)); + else + memset(&context->mq_open.attr, 0, sizeof(struct mq_attr)); + + context->mq_open.oflag = oflag; + context->mq_open.mode = mode; + + context->type = AUDIT_MQ_OPEN; +} + +/** + * __audit_mq_sendrecv - record audit data for a POSIX MQ timed send/receive + * @mqdes: MQ descriptor + * @msg_len: Message length + * @msg_prio: Message priority + * @abs_timeout: Message timeout in absolute time + * + */ +void __audit_mq_sendrecv(mqd_t mqdes, size_t msg_len, unsigned int msg_prio, + const struct timespec *abs_timeout) +{ + struct audit_context *context = current->audit_context; + struct timespec *p = &context->mq_sendrecv.abs_timeout; + + if (abs_timeout) + memcpy(p, abs_timeout, sizeof(struct timespec)); + else + memset(p, 0, sizeof(struct timespec)); + + context->mq_sendrecv.mqdes = mqdes; + context->mq_sendrecv.msg_len = msg_len; + context->mq_sendrecv.msg_prio = msg_prio; + + context->type = AUDIT_MQ_SENDRECV; +} + +/** + * __audit_mq_notify - record audit data for a POSIX MQ notify + * @mqdes: MQ descriptor + * @notification: Notification event + * + */ + +void __audit_mq_notify(mqd_t mqdes, const struct sigevent *notification) +{ + struct audit_context *context = current->audit_context; + + if (notification) + context->mq_notify.sigev_signo = notification->sigev_signo; + else + context->mq_notify.sigev_signo = 0; + + context->mq_notify.mqdes = mqdes; + context->type = AUDIT_MQ_NOTIFY; +} + +/** + * __audit_mq_getsetattr - record audit data for a POSIX MQ get/set attribute + * @mqdes: MQ descriptor + * @mqstat: MQ flags + * + */ +void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat) +{ + struct audit_context *context = current->audit_context; + context->mq_getsetattr.mqdes = mqdes; + context->mq_getsetattr.mqstat = *mqstat; + context->type = AUDIT_MQ_GETSETATTR; +} + +/** + * audit_ipc_obj - record audit data for ipc object + * @ipcp: ipc permissions + * + */ +void __audit_ipc_obj(struct kern_ipc_perm *ipcp) +{ + struct audit_context *context = current->audit_context; + context->ipc.uid = ipcp->uid; + context->ipc.gid = ipcp->gid; + context->ipc.mode = ipcp->mode; + context->ipc.has_perm = 0; + security_ipc_getsecid(ipcp, &context->ipc.osid); + context->type = AUDIT_IPC; +} + +/** + * audit_ipc_set_perm - record audit data for new ipc permissions + * @qbytes: msgq bytes + * @uid: msgq user id + * @gid: msgq group id + * @mode: msgq mode (permissions) + * + * Called only after audit_ipc_obj(). + */ +void __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, umode_t mode) +{ + struct audit_context *context = current->audit_context; + + context->ipc.qbytes = qbytes; + context->ipc.perm_uid = uid; + context->ipc.perm_gid = gid; + context->ipc.perm_mode = mode; + context->ipc.has_perm = 1; +} + +void __audit_bprm(struct linux_binprm *bprm) +{ + struct audit_context *context = current->audit_context; + + context->type = AUDIT_EXECVE; + context->execve.argc = bprm->argc; +} + + +/** + * audit_socketcall - record audit data for sys_socketcall + * @nargs: number of args, which should not be more than AUDITSC_ARGS. + * @args: args array + * + */ +int __audit_socketcall(int nargs, unsigned long *args) +{ + struct audit_context *context = current->audit_context; + + if (nargs <= 0 || nargs > AUDITSC_ARGS || !args) + return -EINVAL; + context->type = AUDIT_SOCKETCALL; + context->socketcall.nargs = nargs; + memcpy(context->socketcall.args, args, nargs * sizeof(unsigned long)); + return 0; +} + +/** + * __audit_fd_pair - record audit data for pipe and socketpair + * @fd1: the first file descriptor + * @fd2: the second file descriptor + * + */ +void __audit_fd_pair(int fd1, int fd2) +{ + struct audit_context *context = current->audit_context; + context->fds[0] = fd1; + context->fds[1] = fd2; +} + +/** + * audit_sockaddr - record audit data for sys_bind, sys_connect, sys_sendto + * @len: data length in user space + * @a: data address in kernel space + * + * Returns 0 for success or NULL context or < 0 on error. + */ +int __audit_sockaddr(int len, void *a) +{ + struct audit_context *context = current->audit_context; + + if (!context->sockaddr) { + void *p = kmalloc(sizeof(struct sockaddr_storage), GFP_KERNEL); + if (!p) + return -ENOMEM; + context->sockaddr = p; + } + + context->sockaddr_len = len; + memcpy(context->sockaddr, a, len); + return 0; +} + +void __audit_ptrace(struct task_struct *t) +{ + struct audit_context *context = current->audit_context; + + context->target_pid = task_pid_nr(t); + context->target_auid = audit_get_loginuid(t); + context->target_uid = task_uid(t); + context->target_sessionid = audit_get_sessionid(t); + security_task_getsecid(t, &context->target_sid); + memcpy(context->target_comm, t->comm, TASK_COMM_LEN); +} + +/** + * audit_signal_info - record signal info for shutting down audit subsystem + * @sig: signal value + * @t: task being signaled + * + * If the audit subsystem is being terminated, record the task (pid) + * and uid that is doing that. + */ +int __audit_signal_info(int sig, struct task_struct *t) +{ + struct audit_aux_data_pids *axp; + struct task_struct *tsk = current; + struct audit_context *ctx = tsk->audit_context; + kuid_t uid = current_uid(), t_uid = task_uid(t); + + if (audit_pid && t->tgid == audit_pid) { + if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1 || sig == SIGUSR2) { + audit_sig_pid = task_pid_nr(tsk); + if (uid_valid(tsk->loginuid)) + audit_sig_uid = tsk->loginuid; + else + audit_sig_uid = uid; + security_task_getsecid(tsk, &audit_sig_sid); + } + if (!audit_signals || audit_dummy_context()) + return 0; + } + + /* optimize the common case by putting first signal recipient directly + * in audit_context */ + if (!ctx->target_pid) { + ctx->target_pid = task_tgid_nr(t); + ctx->target_auid = audit_get_loginuid(t); + ctx->target_uid = t_uid; + ctx->target_sessionid = audit_get_sessionid(t); + security_task_getsecid(t, &ctx->target_sid); + memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN); + return 0; + } + + axp = (void *)ctx->aux_pids; + if (!axp || axp->pid_count == AUDIT_AUX_PIDS) { + axp = kzalloc(sizeof(*axp), GFP_ATOMIC); + if (!axp) + return -ENOMEM; + + axp->d.type = AUDIT_OBJ_PID; + axp->d.next = ctx->aux_pids; + ctx->aux_pids = (void *)axp; + } + BUG_ON(axp->pid_count >= AUDIT_AUX_PIDS); + + axp->target_pid[axp->pid_count] = task_tgid_nr(t); + axp->target_auid[axp->pid_count] = audit_get_loginuid(t); + axp->target_uid[axp->pid_count] = t_uid; + axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t); + security_task_getsecid(t, &axp->target_sid[axp->pid_count]); + memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN); + axp->pid_count++; + + return 0; +} + +/** + * __audit_log_bprm_fcaps - store information about a loading bprm and relevant fcaps + * @bprm: pointer to the bprm being processed + * @new: the proposed new credentials + * @old: the old credentials + * + * Simply check if the proc already has the caps given by the file and if not + * store the priv escalation info for later auditing at the end of the syscall + * + * -Eric + */ +int __audit_log_bprm_fcaps(struct linux_binprm *bprm, + const struct cred *new, const struct cred *old) +{ + struct audit_aux_data_bprm_fcaps *ax; + struct audit_context *context = current->audit_context; + struct cpu_vfs_cap_data vcaps; + + ax = kmalloc(sizeof(*ax), GFP_KERNEL); + if (!ax) + return -ENOMEM; + + ax->d.type = AUDIT_BPRM_FCAPS; + ax->d.next = context->aux; + context->aux = (void *)ax; + + get_vfs_caps_from_disk(bprm->file->f_path.dentry, &vcaps); + + ax->fcap.permitted = vcaps.permitted; + ax->fcap.inheritable = vcaps.inheritable; + ax->fcap.fE = !!(vcaps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE); + ax->fcap_ver = (vcaps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT; + + ax->old_pcap.permitted = old->cap_permitted; + ax->old_pcap.inheritable = old->cap_inheritable; + ax->old_pcap.effective = old->cap_effective; + + ax->new_pcap.permitted = new->cap_permitted; + ax->new_pcap.inheritable = new->cap_inheritable; + ax->new_pcap.effective = new->cap_effective; + return 0; +} + +/** + * __audit_log_capset - store information about the arguments to the capset syscall + * @new: the new credentials + * @old: the old (current) credentials + * + * Record the arguments userspace sent to sys_capset for later printing by the + * audit system if applicable + */ +void __audit_log_capset(const struct cred *new, const struct cred *old) +{ + struct audit_context *context = current->audit_context; + context->capset.pid = task_pid_nr(current); + context->capset.cap.effective = new->cap_effective; + context->capset.cap.inheritable = new->cap_effective; + context->capset.cap.permitted = new->cap_permitted; + context->type = AUDIT_CAPSET; +} + +void __audit_mmap_fd(int fd, int flags) +{ + struct audit_context *context = current->audit_context; + context->mmap.fd = fd; + context->mmap.flags = flags; + context->type = AUDIT_MMAP; +} + +static void audit_log_task(struct audit_buffer *ab) +{ + kuid_t auid, uid; + kgid_t gid; + unsigned int sessionid; + char comm[sizeof(current->comm)]; + + auid = audit_get_loginuid(current); + sessionid = audit_get_sessionid(current); + current_uid_gid(&uid, &gid); + + audit_log_format(ab, "auid=%u uid=%u gid=%u ses=%u", + from_kuid(&init_user_ns, auid), + from_kuid(&init_user_ns, uid), + from_kgid(&init_user_ns, gid), + sessionid); + audit_log_task_context(ab); + audit_log_format(ab, " pid=%d comm=", task_pid_nr(current)); + audit_log_untrustedstring(ab, get_task_comm(comm, current)); + audit_log_d_path_exe(ab, current->mm); +} + +/** + * audit_core_dumps - record information about processes that end abnormally + * @signr: signal value + * + * If a process ends with a core dump, something fishy is going on and we + * should record the event for investigation. + */ +void audit_core_dumps(long signr) +{ + struct audit_buffer *ab; + + if (!audit_enabled) + return; + + if (signr == SIGQUIT) /* don't care for those */ + return; + + ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND); + if (unlikely(!ab)) + return; + audit_log_task(ab); + audit_log_format(ab, " sig=%ld", signr); + audit_log_end(ab); +} + +void __audit_seccomp(unsigned long syscall, long signr, int code) +{ + struct audit_buffer *ab; + + ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_SECCOMP); + if (unlikely(!ab)) + return; + audit_log_task(ab); + audit_log_format(ab, " sig=%ld arch=%x syscall=%ld compat=%d ip=0x%lx code=0x%x", + signr, syscall_get_arch(), syscall, is_compat_task(), + KSTK_EIP(current), code); + audit_log_end(ab); +} + +struct list_head *audit_killed_trees(void) +{ + struct audit_context *ctx = current->audit_context; + if (likely(!ctx || !ctx->in_syscall)) + return NULL; + return &ctx->killed_trees; +} |