/* 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. */ #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 <linux/capability.h> #include <linux/fs_struct.h> #include <linux/compat.h> #include "audit.h" /* flags stating the success for a syscall */ #define AUDITSC_INVALID 0 #define AUDITSC_SUCCESS 1 #define AUDITSC_FAILURE 2 /* AUDIT_NAMES is the number of slots we reserve in the audit_context * for saving names from getname(). If we get more names we will allocate * a name dynamically and also add those to the list anchored by names_list. */ #define AUDIT_NAMES 5 /* Indicates that audit should log the full pathname. */ #define AUDIT_NAME_FULL -1 /* no execve audit message should be longer than this (userspace limits) */ #define MAX_EXECVE_AUDIT_LEN 7500 /* number of audit rules */ int audit_n_rules; /* determines whether we collect data for signals sent */ int audit_signals; struct audit_cap_data { kernel_cap_t permitted; kernel_cap_t inheritable; union { unsigned int fE; /* effective bit of a file capability */ kernel_cap_t effective; /* effective set of a process */ }; }; /* When fs/namei.c:getname() is called, we store the pointer in name and * we don't let putname() free it (instead we free all of the saved * pointers at syscall exit time). * * Further, in fs/namei.c:path_lookup() we store the inode and device. */ struct audit_names { struct list_head list; /* audit_context->names_list */ const char *name; unsigned long ino; dev_t dev; umode_t mode; uid_t uid; gid_t gid; dev_t rdev; u32 osid; struct audit_cap_data fcap; unsigned int fcap_ver; int name_len; /* number of name's characters to log */ bool name_put; /* call __putname() for this name */ /* * This was an allocated audit_names and not from the array of * names allocated in the task audit context. Thus this name * should be freed on syscall exit */ bool should_free; }; 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_execve { struct audit_aux_data d; int argc; int envc; struct mm_struct *mm; }; struct audit_aux_data_pids { struct audit_aux_data d; pid_t target_pid[AUDIT_AUX_PIDS]; uid_t target_auid[AUDIT_AUX_PIDS]; uid_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_aux_data_capset { struct audit_aux_data d; pid_t pid; struct audit_cap_data cap; }; struct audit_tree_refs { struct audit_tree_refs *next; struct audit_chunk *c[31]; }; /* The per-task audit context. */ struct audit_context { int dummy; /* must be the first element */ int in_syscall; /* 1 if task is in a syscall */ enum audit_state state, current_state; unsigned int serial; /* serial number for record */ int major; /* syscall number */ struct timespec ctime; /* time of syscall entry */ unsigned long argv[4]; /* syscall arguments */ long return_code;/* syscall return code */ u64 prio; int return_valid; /* return code is valid */ /* * The names_list is the list of all audit_names collected during this * syscall. The first AUDIT_NAMES entries in the names_list will * actually be from the preallocated_names array for performance * reasons. Except during allocation they should never be referenced * through the preallocated_names array and should only be found/used * by running the names_list. */ struct audit_names preallocated_names[AUDIT_NAMES]; int name_count; /* total records in names_list */ struct list_head names_list; /* anchor for struct audit_names->list */ char * filterkey; /* key for rule that triggered record */ struct path pwd; struct audit_context *previous; /* For nested syscalls */ struct audit_aux_data *aux; struct audit_aux_data *aux_pids; struct sockaddr_storage *sockaddr; size_t sockaddr_len; /* Save things to print about task_struct */ pid_t pid, ppid; uid_t uid, euid, suid, fsuid; gid_t gid, egid, sgid, fsgid; unsigned long personality; int arch; pid_t target_pid; uid_t target_auid; uid_t target_uid; unsigned int target_sessionid; u32 target_sid; char target_comm[TASK_COMM_LEN]; struct audit_tree_refs *trees, *first_trees; struct list_head killed_trees; int tree_count; int type; union { struct { int nargs; long args[6]; } socketcall; struct { uid_t uid; gid_t gid; umode_t mode; u32 osid; int has_perm; uid_t perm_uid; gid_t perm_gid; umode_t perm_mode; unsigned long qbytes; } ipc; struct { mqd_t mqdes; struct mq_attr mqstat; } mq_getsetattr; struct { mqd_t mqdes; int sigev_signo; } mq_notify; struct { mqd_t mqdes; size_t msg_len; unsigned int msg_prio; struct timespec abs_timeout; } mq_sendrecv; struct { int oflag; umode_t mode; struct mq_attr attr; } mq_open; struct { pid_t pid; struct audit_cap_data cap; } capset; struct { int fd; int flags; } mmap; }; int fds[2]; #if AUDIT_DEBUG int put_count; int ino_count; #endif }; static inline int open_arg(int flags, int mask) { int n = ACC_MODE(flags); if (flags & (O_TRUNC | O_CREAT)) n |= AUDIT_PERM_WRITE; return n & mask; } 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_id(uid_t uid1, struct audit_names *name, unsigned long name_offset, struct audit_field *f, struct audit_context *ctx) { struct audit_names *n; unsigned long addr; uid_t uid2; int rc; BUILD_BUG_ON(sizeof(uid_t) != sizeof(gid_t)); if (name) { addr = (unsigned long)name; addr += name_offset; uid2 = *(uid_t *)addr; rc = audit_comparator(uid1, f->op, uid2); if (rc) return rc; } if (ctx) { list_for_each_entry(n, &ctx->names_list, list) { addr = (unsigned long)n; addr += name_offset; uid2 = *(uid_t *)addr; rc = audit_comparator(uid1, f->op, uid2); 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_id(cred->uid, name, offsetof(struct audit_names, uid), f, ctx); case AUDIT_COMPARE_GID_TO_OBJ_GID: return audit_compare_id(cred->gid, name, offsetof(struct audit_names, gid), f, ctx); case AUDIT_COMPARE_EUID_TO_OBJ_UID: return audit_compare_id(cred->euid, name, offsetof(struct audit_names, uid), f, ctx); case AUDIT_COMPARE_EGID_TO_OBJ_GID: return audit_compare_id(cred->egid, name, offsetof(struct audit_names, gid), f, ctx); case AUDIT_COMPARE_AUID_TO_OBJ_UID: return audit_compare_id(tsk->loginuid, name, offsetof(struct audit_names, uid), f, ctx); case AUDIT_COMPARE_SUID_TO_OBJ_UID: return audit_compare_id(cred->suid, name, offsetof(struct audit_names, uid), f, ctx); case AUDIT_COMPARE_SGID_TO_OBJ_GID: return audit_compare_id(cred->sgid, name, offsetof(struct audit_names, gid), f, ctx); case AUDIT_COMPARE_FSUID_TO_OBJ_UID: return audit_compare_id(cred->fsuid, name, offsetof(struct audit_names, uid), f, ctx); case AUDIT_COMPARE_FSGID_TO_OBJ_GID: return audit_compare_id(cred->fsgid, name, offsetof(struct audit_names, gid), f, ctx); /* uid comparisons */ case AUDIT_COMPARE_UID_TO_AUID: return audit_comparator(cred->uid, f->op, tsk->loginuid); case AUDIT_COMPARE_UID_TO_EUID: return audit_comparator(cred->uid, f->op, cred->euid); case AUDIT_COMPARE_UID_TO_SUID: return audit_comparator(cred->uid, f->op, cred->suid); case AUDIT_COMPARE_UID_TO_FSUID: return audit_comparator(cred->uid, f->op, cred->fsuid); /* auid comparisons */ case AUDIT_COMPARE_AUID_TO_EUID: return audit_comparator(tsk->loginuid, f->op, cred->euid); case AUDIT_COMPARE_AUID_TO_SUID: return audit_comparator(tsk->loginuid, f->op, cred->suid); case AUDIT_COMPARE_AUID_TO_FSUID: return audit_comparator(tsk->loginuid, f->op, cred->fsuid); /* euid comparisons */ case AUDIT_COMPARE_EUID_TO_SUID: return audit_comparator(cred->euid, f->op, cred->suid); case AUDIT_COMPARE_EUID_TO_FSUID: return audit_comparator(cred->euid, f->op, cred->fsuid); /* suid comparisons */ case AUDIT_COMPARE_SUID_TO_FSUID: return audit_comparator(cred->suid, f->op, cred->fsuid); /* gid comparisons */ case AUDIT_COMPARE_GID_TO_EGID: return audit_comparator(cred->gid, f->op, cred->egid); case AUDIT_COMPARE_GID_TO_SGID: return audit_comparator(cred->gid, f->op, cred->sgid); case AUDIT_COMPARE_GID_TO_FSGID: return audit_comparator(cred->gid, f->op, cred->fsgid); /* egid comparisons */ case AUDIT_COMPARE_EGID_TO_SGID: return audit_comparator(cred->egid, f->op, cred->sgid); case AUDIT_COMPARE_EGID_TO_FSGID: return audit_comparator(cred->egid, f->op, cred->fsgid); /* sgid comparison */ case AUDIT_COMPARE_SGID_TO_FSGID: return audit_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; switch (f->type) { case AUDIT_PID: result = audit_comparator(tsk->pid, f->op, f->val); break; case AUDIT_PPID: if (ctx) { if (!ctx->ppid) ctx->ppid = sys_getppid(); result = audit_comparator(ctx->ppid, f->op, f->val); } break; case AUDIT_UID: result = audit_comparator(cred->uid, f->op, f->val); break; case AUDIT_EUID: result = audit_comparator(cred->euid, f->op, f->val); break; case AUDIT_SUID: result = audit_comparator(cred->suid, f->op, f->val); break; case AUDIT_FSUID: result = audit_comparator(cred->fsuid, f->op, f->val); break; case AUDIT_GID: result = audit_comparator(cred->gid, f->op, f->val); break; case AUDIT_EGID: result = audit_comparator(cred->egid, f->op, f->val); break; case AUDIT_SGID: result = audit_comparator(cred->sgid, f->op, f->val); break; case AUDIT_FSGID: result = audit_comparator(cred->fsgid, f->op, f->val); 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 = (name->ino == 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_comparator(name->uid, f->op, f->val); } else if (ctx) { list_for_each_entry(n, &ctx->names_list, list) { if (audit_comparator(n->uid, f->op, f->val)) { ++result; break; } } } break; case AUDIT_OBJ_GID: if (name) { result = audit_comparator(name->gid, f->op, f->val); } else if (ctx) { list_for_each_entry(n, &ctx->names_list, list) { if (audit_comparator(n->gid, f->op, f->val)) { ++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_comparator(tsk->loginuid, 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; } /* 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)) { int word = AUDIT_WORD(ctx->major); int bit = AUDIT_BIT(ctx->major); list_for_each_entry_rcu(e, list, list) { if ((e->rule.mask[word] & bit) == bit && 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 word, bit; int h = audit_hash_ino((u32)n->ino); struct list_head *list = &audit_inode_hash[h]; struct audit_entry *e; enum audit_state state; word = AUDIT_WORD(ctx->major); bit = AUDIT_BIT(ctx->major); if (list_empty(list)) return 0; list_for_each_entry_rcu(e, list, list) { if ((e->rule.mask[word] & bit) == bit && 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(); } static inline struct audit_context *audit_get_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_free_names(struct audit_context *context) { struct audit_names *n, *next; #if AUDIT_DEBUG == 2 if (context->put_count + context->ino_count != context->name_count) { printk(KERN_ERR "%s:%d(:%d): major=%d in_syscall=%d" " name_count=%d put_count=%d" " ino_count=%d [NOT freeing]\n", __FILE__, __LINE__, context->serial, context->major, context->in_syscall, context->name_count, context->put_count, context->ino_count); list_for_each_entry(n, &context->names_list, list) { printk(KERN_ERR "names[%d] = %p = %s\n", i, n->name, n->name ?: "(null)"); } dump_stack(); return; } #endif #if AUDIT_DEBUG context->put_count = 0; context->ino_count = 0; #endif list_for_each_entry_safe(n, next, &context->names_list, list) { list_del(&n->list); if (n->name && n->name_put) __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 void audit_zero_context(struct audit_context *context, enum audit_state state) { memset(context, 0, sizeof(*context)); context->state = state; context->prio = state == AUDIT_RECORD_CONTEXT ? ~0ULL : 0; } static inline struct audit_context *audit_alloc_context(enum audit_state state) { struct audit_context *context; if (!(context = kmalloc(sizeof(*context), GFP_KERNEL))) return NULL; audit_zero_context(context, state); 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) 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) { struct audit_context *previous; int count = 0; do { previous = context->previous; if (previous || (count && count < 10)) { ++count; printk(KERN_ERR "audit(:%d): major=%d name_count=%d:" " freeing multiple contexts (%d)\n", context->serial, context->major, context->name_count, count); } audit_free_names(context); unroll_tree_refs(context, NULL, 0); free_tree_refs(context); audit_free_aux(context); kfree(context->filterkey); kfree(context->sockaddr); kfree(context); context = previous; } while (context); if (count >= 10) printk(KERN_ERR "audit: freed %d contexts\n", count); } void audit_log_task_context(struct audit_buffer *ab) { char *ctx = NULL; unsigned len; int error; u32 sid; security_task_getsecid(current, &sid); if (!sid) return; error = security_secid_to_secctx(sid, &ctx, &len); if (error) { if (error != -EINVAL) goto error_path; return; } audit_log_format(ab, " subj=%s", ctx); security_release_secctx(ctx, len); return; error_path: audit_panic("error in audit_log_task_context"); return; } EXPORT_SYMBOL(audit_log_task_context); static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk) { char name[sizeof(tsk->comm)]; struct mm_struct *mm = tsk->mm; struct vm_area_struct *vma; /* tsk == current */ get_task_comm(name, tsk); audit_log_format(ab, " comm="); audit_log_untrustedstring(ab, name); if (mm) { down_read(&mm->mmap_sem); vma = mm->mmap; while (vma) { if ((vma->vm_flags & VM_EXECUTABLE) && vma->vm_file) { audit_log_d_path(ab, " exe=", &vma->vm_file->f_path); break; } vma = vma->vm_next; } up_read(&mm->mmap_sem); } audit_log_task_context(ab); } static int audit_log_pid_context(struct audit_context *context, pid_t pid, uid_t auid, uid_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, auid, uid, sessionid); 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, struct audit_aux_data_execve *axi) { int i, len; size_t len_sent = 0; const char __user *p; char *buf; if (axi->mm != current->mm) return; /* execve failed, no additional info */ p = (const char __user *)axi->mm->arg_start; audit_log_format(*ab, "argc=%d", axi->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\n"); return; } for (i = 0; i < axi->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 audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap) { int i; audit_log_format(ab, " %s=", prefix); CAP_FOR_EACH_U32(i) { audit_log_format(ab, "%08x", cap->cap[(_KERNEL_CAPABILITY_U32S-1) - i]); } } static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name) { kernel_cap_t *perm = &name->fcap.permitted; kernel_cap_t *inh = &name->fcap.inheritable; int log = 0; if (!cap_isclear(*perm)) { audit_log_cap(ab, "cap_fp", perm); log = 1; } if (!cap_isclear(*inh)) { audit_log_cap(ab, "cap_fi", inh); log = 1; } if (log) audit_log_format(ab, " cap_fe=%d cap_fver=%x", name->fcap.fE, name->fcap_ver); } 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", context->ipc.uid, 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); 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); if (!ab) return; } 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; } } audit_log_end(ab); } static void audit_log_name(struct audit_context *context, struct audit_names *n, int record_num, int *call_panic) { struct audit_buffer *ab; ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH); if (!ab) return; /* audit_panic has been called */ audit_log_format(ab, "item=%d", record_num); if (n->name) { switch (n->name_len) { case AUDIT_NAME_FULL: /* log the full path */ audit_log_format(ab, " name="); audit_log_untrustedstring(ab, n->name); break; case 0: /* name was specified as a relative path and the * directory component is the cwd */ audit_log_d_path(ab, " name=", &context->pwd); break; default: /* log the name's directory component */ audit_log_format(ab, " name="); audit_log_n_untrustedstring(ab, n->name, n->name_len); } } else audit_log_format(ab, " name=(null)"); if (n->ino != (unsigned long)-1) { audit_log_format(ab, " inode=%lu" " dev=%02x:%02x mode=%#ho" " ouid=%u ogid=%u rdev=%02x:%02x", n->ino, MAJOR(n->dev), MINOR(n->dev), n->mode, n->uid, n->gid, MAJOR(n->rdev), MINOR(n->rdev)); } if (n->osid != 0) { char *ctx = NULL; u32 len; if (security_secid_to_secctx( n->osid, &ctx, &len)) { audit_log_format(ab, " osid=%u", n->osid); *call_panic = 2; } else { audit_log_format(ab, " obj=%s", ctx); security_release_secctx(ctx, len); } } audit_log_fcaps(ab, n); audit_log_end(ab); } static void audit_log_exit(struct audit_context *context, struct task_struct *tsk) { const struct cred *cred; int i, call_panic = 0; struct audit_buffer *ab; struct audit_aux_data *aux; const char *tty; struct audit_names *n; /* tsk == current */ context->pid = tsk->pid; if (!context->ppid) context->ppid = sys_getppid(); cred = current_cred(); context->uid = cred->uid; context->gid = cred->gid; context->euid = cred->euid; context->suid = cred->suid; context->fsuid = cred->fsuid; context->egid = cred->egid; context->sgid = cred->sgid; context->fsgid = cred->fsgid; 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); spin_lock_irq(&tsk->sighand->siglock); if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name) tty = tsk->signal->tty->name; else tty = "(none)"; spin_unlock_irq(&tsk->sighand->siglock); audit_log_format(ab, " a0=%lx a1=%lx a2=%lx a3=%lx items=%d" " ppid=%d pid=%d auid=%u uid=%u gid=%u" " euid=%u suid=%u fsuid=%u" " egid=%u sgid=%u fsgid=%u tty=%s ses=%u", context->argv[0], context->argv[1], context->argv[2], context->argv[3], context->name_count, context->ppid, context->pid, tsk->loginuid, context->uid, context->gid, context->euid, context->suid, context->fsuid, context->egid, context->sgid, context->fsgid, tty, tsk->sessionid); 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_EXECVE: { struct audit_aux_data_execve *axi = (void *)aux; audit_log_execve_info(context, &ab, axi); break; } 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) audit_log_name(context, n, i++, &call_panic); /* 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_get_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 * @arch: architecture type * @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 arch, 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; /* * This happens only on certain architectures that make system * calls in kernel_thread via the entry.S interface, instead of * with direct calls. (If you are porting to a new * architecture, hitting this condition can indicate that you * got the _exit/_leave calls backward in entry.S.) * * i386 no * x86_64 no * ppc64 yes (see arch/powerpc/platforms/iseries/misc.S) * * This also happens with vm86 emulation in a non-nested manner * (entries without exits), so this case must be caught. */ if (context->in_syscall) { struct audit_context *newctx; #if AUDIT_DEBUG printk(KERN_ERR "audit(:%d) pid=%d in syscall=%d;" " entering syscall=%d\n", context->serial, tsk->pid, context->major, major); #endif newctx = audit_alloc_context(context->state); if (newctx) { newctx->previous = context; context = newctx; tsk->audit_context = newctx; } else { /* If we can't alloc a new context, the best we * can do is to leak memory (any pending putname * will be lost). The only other alternative is * to abandon auditing. */ audit_zero_context(context, context->state); } } BUG_ON(context->in_syscall || context->name_count); if (!audit_enabled) return; context->arch = 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_get_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); if (context->previous) { struct audit_context *new_context = context->previous; context->previous = NULL; audit_free_context(context); tsk->audit_context = new_context; } else { 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))) { printk(KERN_WARNING "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->d_inode; 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 */ printk(KERN_WARNING "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) { 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; list_add_tail(&aname->list, &context->names_list); context->name_count++; #if AUDIT_DEBUG context->ino_count++; #endif return aname; } /** * 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(const char *name) { struct audit_context *context = current->audit_context; struct audit_names *n; if (!context->in_syscall) { #if AUDIT_DEBUG == 2 printk(KERN_ERR "%s:%d(:%d): ignoring getname(%p)\n", __FILE__, __LINE__, context->serial, name); dump_stack(); #endif return; } n = audit_alloc_name(context); if (!n) return; n->name = name; n->name_len = AUDIT_NAME_FULL; n->name_put = true; if (!context->pwd.dentry) get_fs_pwd(current->fs, &context->pwd); } /* audit_putname - intercept a putname request * @name: name to intercept and delay for putname * * If we have stored the name from getname in the audit context, * then we delay the putname until syscall exit. * Called from include/linux/fs.h:putname(). */ void audit_putname(const char *name) { struct audit_context *context = current->audit_context; BUG_ON(!context); if (!context->in_syscall) { #if AUDIT_DEBUG == 2 printk(KERN_ERR "%s:%d(:%d): __putname(%p)\n", __FILE__, __LINE__, context->serial, name); if (context->name_count) { struct audit_names *n; int i; list_for_each_entry(n, &context->names_list, list) printk(KERN_ERR "name[%d] = %p = %s\n", i, n->name, n->name ?: "(null)"); } #endif __putname(name); } #if AUDIT_DEBUG else { ++context->put_count; if (context->put_count > context->name_count) { printk(KERN_ERR "%s:%d(:%d): major=%d" " in_syscall=%d putname(%p) name_count=%d" " put_count=%d\n", __FILE__, __LINE__, context->serial, context->major, context->in_syscall, name, context->name_count, context->put_count); dump_stack(); } } #endif } static inline int audit_copy_fcaps(struct audit_names *name, const struct dentry *dentry) { struct cpu_vfs_cap_data caps; int rc; if (!dentry) return 0; rc = get_vfs_caps_from_disk(dentry, &caps); if (rc) return rc; name->fcap.permitted = caps.permitted; name->fcap.inheritable = caps.inheritable; name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE); name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >> VFS_CAP_REVISION_SHIFT; return 0; } /* Copy inode data into an audit_names. */ static void audit_copy_inode(struct audit_names *name, const struct dentry *dentry, const struct inode *inode) { name->ino = inode->i_ino; name->dev = inode->i_sb->s_dev; name->mode = inode->i_mode; name->uid = inode->i_uid; name->gid = inode->i_gid; name->rdev = inode->i_rdev; security_inode_getsecid(inode, &name->osid); audit_copy_fcaps(name, dentry); } /** * audit_inode - store the inode and device from a lookup * @name: name being audited * @dentry: dentry being audited * * Called from fs/namei.c:path_lookup(). */ void __audit_inode(const char *name, const struct dentry *dentry) { struct audit_context *context = current->audit_context; const struct inode *inode = dentry->d_inode; struct audit_names *n; if (!context->in_syscall) return; list_for_each_entry_reverse(n, &context->names_list, list) { if (n->name && (n->name == name)) goto out; } /* unable to find the name from a previous getname() */ n = audit_alloc_name(context); if (!n) return; out: handle_path(dentry); audit_copy_inode(n, dentry, inode); } /** * audit_inode_child - collect inode info for created/removed objects * @dentry: dentry being audited * @parent: inode of dentry parent * * 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 dentry *dentry, const struct inode *parent) { struct audit_context *context = current->audit_context; const char *found_parent = NULL, *found_child = NULL; const struct inode *inode = dentry->d_inode; const char *dname = dentry->d_name.name; struct audit_names *n; int dirlen = 0; if (!context->in_syscall) return; if (inode) handle_one(inode); /* parent is more likely, look for it first */ list_for_each_entry(n, &context->names_list, list) { if (!n->name) continue; if (n->ino == parent->i_ino && !audit_compare_dname_path(dname, n->name, &dirlen)) { n->name_len = dirlen; /* update parent data in place */ found_parent = n->name; goto add_names; } } /* no matching parent, look for matching child */ list_for_each_entry(n, &context->names_list, list) { if (!n->name) continue; /* strcmp() is the more likely scenario */ if (!strcmp(dname, n->name) || !audit_compare_dname_path(dname, n->name, &dirlen)) { if (inode) audit_copy_inode(n, NULL, inode); else n->ino = (unsigned long)-1; found_child = n->name; goto add_names; } } add_names: if (!found_parent) { n = audit_alloc_name(context); if (!n) return; audit_copy_inode(n, NULL, parent); } if (!found_child) { n = audit_alloc_name(context); if (!n) 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) { n->name = found_parent; n->name_len = AUDIT_NAME_FULL; /* don't call __putname() */ n->name_put = false; } if (inode) audit_copy_inode(n, NULL, inode); } } 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); /** * 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(uid_t loginuid) { struct task_struct *task = current; struct audit_context *context = task->audit_context; unsigned int sessionid; #ifdef CONFIG_AUDIT_LOGINUID_IMMUTABLE if (task->loginuid != -1) return -EPERM; #else /* CONFIG_AUDIT_LOGINUID_IMMUTABLE */ if (!capable(CAP_AUDIT_CONTROL)) return -EPERM; #endif /* CONFIG_AUDIT_LOGINUID_IMMUTABLE */ sessionid = atomic_inc_return(&session_id); if (context && context->in_syscall) { struct audit_buffer *ab; ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN); if (ab) { audit_log_format(ab, "login pid=%d uid=%u " "old auid=%u new auid=%u" " old ses=%u new ses=%u", task->pid, task_uid(task), task->loginuid, loginuid, task->sessionid, sessionid); audit_log_end(ab); } } task->sessionid = sessionid; task->loginuid = loginuid; return 0; } /** * __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; } int __audit_bprm(struct linux_binprm *bprm) { struct audit_aux_data_execve *ax; struct audit_context *context = current->audit_context; ax = kmalloc(sizeof(*ax), GFP_KERNEL); if (!ax) return -ENOMEM; ax->argc = bprm->argc; ax->envc = bprm->envc; ax->mm = bprm->mm; ax->d.type = AUDIT_EXECVE; ax->d.next = context->aux; context->aux = (void *)ax; return 0; } /** * audit_socketcall - record audit data for sys_socketcall * @nargs: number of args * @args: args array * */ void __audit_socketcall(int nargs, unsigned long *args) { struct audit_context *context = current->audit_context; context->type = AUDIT_SOCKETCALL; context->socketcall.nargs = nargs; memcpy(context->socketcall.args, args, nargs * sizeof(unsigned long)); } /** * __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 = t->pid; 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; uid_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 = tsk->pid; if (tsk->loginuid != -1) 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 = t->tgid; 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] = t->tgid; 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; struct dentry *dentry; 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; dentry = dget(bprm->file->f_dentry); get_vfs_caps_from_disk(dentry, &vcaps); dput(dentry); 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 * @pid: target pid of the capset call * @new: the new credentials * @old: the old (current) credentials * * Record the aguments userspace sent to sys_capset for later printing by the * audit system if applicable */ void __audit_log_capset(pid_t pid, const struct cred *new, const struct cred *old) { struct audit_context *context = current->audit_context; context->capset.pid = pid; 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_abend(struct audit_buffer *ab, char *reason, long signr) { uid_t auid, uid; gid_t gid; unsigned int sessionid; 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", auid, uid, gid, sessionid); audit_log_task_context(ab); audit_log_format(ab, " pid=%d comm=", current->pid); audit_log_untrustedstring(ab, current->comm); audit_log_format(ab, " reason="); audit_log_string(ab, reason); audit_log_format(ab, " sig=%ld", signr); } /** * 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); audit_log_abend(ab, "memory violation", 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_ANOM_ABEND); audit_log_abend(ab, "seccomp", signr); audit_log_format(ab, " syscall=%ld", syscall); audit_log_format(ab, " compat=%d", is_compat_task()); audit_log_format(ab, " ip=0x%lx", KSTK_EIP(current)); audit_log_format(ab, " code=0x%x", 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; }