/* 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; }