/* 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 <asm/atomic.h> #include <asm/types.h> #include <linux/fs.h> #include <linux/namei.h> #include <linux/mm.h> #include <linux/module.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/selinux.h> #include <linux/binfmts.h> #include <linux/syscalls.h> #include "audit.h" extern struct list_head audit_filter_list[]; /* No syscall auditing will take place unless audit_enabled != 0. */ extern int audit_enabled; /* AUDIT_NAMES is the number of slots we reserve in the audit_context * for saving names from getname(). */ #define AUDIT_NAMES 20 /* AUDIT_NAMES_RESERVED is the number of slots we reserve in the * audit_context from being used for nameless inodes from * path_lookup. */ #define AUDIT_NAMES_RESERVED 7 /* Indicates that audit should log the full pathname. */ #define AUDIT_NAME_FULL -1 /* number of audit rules */ int audit_n_rules; /* 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 { const char *name; int name_len; /* number of name's characters to log */ unsigned name_put; /* call __putname() for this name */ unsigned long ino; dev_t dev; umode_t mode; uid_t uid; gid_t gid; dev_t rdev; u32 osid; }; struct audit_aux_data { struct audit_aux_data *next; int type; }; #define AUDIT_AUX_IPCPERM 0 struct audit_aux_data_mq_open { struct audit_aux_data d; int oflag; mode_t mode; struct mq_attr attr; }; struct audit_aux_data_mq_sendrecv { struct audit_aux_data d; mqd_t mqdes; size_t msg_len; unsigned int msg_prio; struct timespec abs_timeout; }; struct audit_aux_data_mq_notify { struct audit_aux_data d; mqd_t mqdes; struct sigevent notification; }; struct audit_aux_data_mq_getsetattr { struct audit_aux_data d; mqd_t mqdes; struct mq_attr mqstat; }; struct audit_aux_data_ipcctl { struct audit_aux_data d; struct ipc_perm p; unsigned long qbytes; uid_t uid; gid_t gid; mode_t mode; u32 osid; }; struct audit_aux_data_execve { struct audit_aux_data d; int argc; int envc; char mem[0]; }; struct audit_aux_data_socketcall { struct audit_aux_data d; int nargs; unsigned long args[0]; }; struct audit_aux_data_sockaddr { struct audit_aux_data d; int len; char a[0]; }; struct audit_aux_data_path { struct audit_aux_data d; struct dentry *dentry; struct vfsmount *mnt; }; /* 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; unsigned int serial; /* serial number for record */ struct timespec ctime; /* time of syscall entry */ uid_t loginuid; /* login uid (identity) */ int major; /* syscall number */ unsigned long argv[4]; /* syscall arguments */ int return_valid; /* return code is valid */ long return_code;/* syscall return code */ int auditable; /* 1 if record should be written */ int name_count; struct audit_names names[AUDIT_NAMES]; char * filterkey; /* key for rule that triggered record */ struct dentry * pwd; struct vfsmount * pwdmnt; struct audit_context *previous; /* For nested syscalls */ struct audit_aux_data *aux; /* 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; #if AUDIT_DEBUG int put_count; int ino_count; #endif }; #define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE]) 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 = 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; } } /* 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. */ 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) { int i, j, need_sid = 1; u32 sid; for (i = 0; i < rule->field_count; i++) { struct audit_field *f = &rule->fields[i]; int result = 0; switch (f->type) { case AUDIT_PID: result = audit_comparator(tsk->pid, f->op, f->val); break; case AUDIT_PPID: if (ctx) result = audit_comparator(ctx->ppid, f->op, f->val); break; case AUDIT_UID: result = audit_comparator(tsk->uid, f->op, f->val); break; case AUDIT_EUID: result = audit_comparator(tsk->euid, f->op, f->val); break; case AUDIT_SUID: result = audit_comparator(tsk->suid, f->op, f->val); break; case AUDIT_FSUID: result = audit_comparator(tsk->fsuid, f->op, f->val); break; case AUDIT_GID: result = audit_comparator(tsk->gid, f->op, f->val); break; case AUDIT_EGID: result = audit_comparator(tsk->egid, f->op, f->val); break; case AUDIT_SGID: result = audit_comparator(tsk->sgid, f->op, f->val); break; case AUDIT_FSGID: result = audit_comparator(tsk->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) result = audit_comparator(MAJOR(name->dev), f->op, f->val); else if (ctx) { for (j = 0; j < ctx->name_count; j++) { if (audit_comparator(MAJOR(ctx->names[j].dev), f->op, f->val)) { ++result; break; } } } break; case AUDIT_DEVMINOR: if (name) result = audit_comparator(MINOR(name->dev), f->op, f->val); else if (ctx) { for (j = 0; j < ctx->name_count; j++) { if (audit_comparator(MINOR(ctx->names[j].dev), f->op, f->val)) { ++result; break; } } } break; case AUDIT_INODE: if (name) result = (name->ino == f->val); else if (ctx) { for (j = 0; j < ctx->name_count; j++) { if (audit_comparator(ctx->names[j].ino, f->op, f->val)) { ++result; break; } } } break; case AUDIT_WATCH: if (name && rule->watch->ino != (unsigned long)-1) result = (name->dev == rule->watch->dev && name->ino == rule->watch->ino); break; case AUDIT_LOGINUID: result = 0; if (ctx) result = audit_comparator(ctx->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->se_rule) { if (need_sid) { selinux_get_task_sid(tsk, &sid); need_sid = 0; } result = selinux_audit_rule_match(sid, f->type, f->op, f->se_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->se_rule) { /* Find files that match */ if (name) { result = selinux_audit_rule_match( name->osid, f->type, f->op, f->se_rule, ctx); } else if (ctx) { for (j = 0; j < ctx->name_count; j++) { if (selinux_audit_rule_match( ctx->names[j].osid, f->type, f->op, f->se_rule, ctx)) { ++result; break; } } } /* Find ipc objects that match */ if (ctx) { struct audit_aux_data *aux; for (aux = ctx->aux; aux; aux = aux->next) { if (aux->type == AUDIT_IPC) { struct audit_aux_data_ipcctl *axi = (void *)aux; if (selinux_audit_rule_match(axi->osid, f->type, f->op, f->se_rule, ctx)) { ++result; break; } } } } } 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; } if (!result) return 0; } if (rule->filterkey) ctx->filterkey = kstrdup(rule->filterkey, GFP_ATOMIC); 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) { 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)) { 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)) { rcu_read_unlock(); return state; } } } rcu_read_unlock(); return AUDIT_BUILD_CONTEXT; } /* 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(). */ enum audit_state audit_filter_inodes(struct task_struct *tsk, struct audit_context *ctx) { int i; struct audit_entry *e; enum audit_state state; if (audit_pid && tsk->tgid == audit_pid) return AUDIT_DISABLED; rcu_read_lock(); for (i = 0; i < ctx->name_count; i++) { int word = AUDIT_WORD(ctx->major); int bit = AUDIT_BIT(ctx->major); struct audit_names *n = &ctx->names[i]; int h = audit_hash_ino((u32)n->ino); struct list_head *list = &audit_inode_hash[h]; if (list_empty(list)) continue; list_for_each_entry_rcu(e, list, list) { if ((e->rule.mask[word] & bit) == bit && audit_filter_rules(tsk, &e->rule, ctx, n, &state)) { rcu_read_unlock(); return state; } } } rcu_read_unlock(); return AUDIT_BUILD_CONTEXT; } void audit_set_auditable(struct audit_context *ctx) { ctx->auditable = 1; } static inline struct audit_context *audit_get_context(struct task_struct *tsk, int return_valid, int return_code) { struct audit_context *context = tsk->audit_context; if (likely(!context)) return NULL; context->return_valid = return_valid; context->return_code = return_code; if (context->in_syscall && !context->dummy && !context->auditable) { enum audit_state state; state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]); if (state == AUDIT_RECORD_CONTEXT) { context->auditable = 1; goto get_context; } state = audit_filter_inodes(tsk, context); if (state == AUDIT_RECORD_CONTEXT) context->auditable = 1; } get_context: tsk->audit_context = NULL; return context; } static inline void audit_free_names(struct audit_context *context) { int i; #if AUDIT_DEBUG == 2 if (context->auditable ||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); for (i = 0; i < context->name_count; i++) { printk(KERN_ERR "names[%d] = %p = %s\n", i, context->names[i].name, context->names[i].name ?: "(null)"); } dump_stack(); return; } #endif #if AUDIT_DEBUG context->put_count = 0; context->ino_count = 0; #endif for (i = 0; i < context->name_count; i++) { if (context->names[i].name && context->names[i].name_put) __putname(context->names[i].name); } context->name_count = 0; if (context->pwd) dput(context->pwd); if (context->pwdmnt) mntput(context->pwdmnt); context->pwd = NULL; context->pwdmnt = NULL; } static inline void audit_free_aux(struct audit_context *context) { struct audit_aux_data *aux; while ((aux = context->aux)) { if (aux->type == AUDIT_AVC_PATH) { struct audit_aux_data_path *axi = (void *)aux; dput(axi->dentry); mntput(axi->mnt); } context->aux = aux->next; kfree(aux); } } static inline void audit_zero_context(struct audit_context *context, enum audit_state state) { uid_t loginuid = context->loginuid; memset(context, 0, sizeof(*context)); context->state = state; context->loginuid = loginuid; } 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); 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; if (likely(!audit_enabled)) return 0; /* Return if not auditing. */ state = audit_filter_task(tsk); if (likely(state == AUDIT_DISABLED)) return 0; if (!(context = audit_alloc_context(state))) { audit_log_lost("out of memory in audit_alloc"); return -ENOMEM; } /* Preserve login uid */ context->loginuid = -1; if (current->audit_context) context->loginuid = current->audit_context->loginuid; 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); audit_free_aux(context); kfree(context->filterkey); kfree(context); context = previous; } while (context); if (count >= 10) printk(KERN_ERR "audit: freed %d contexts\n", count); } static void audit_log_task_context(struct audit_buffer *ab) { char *ctx = NULL; ssize_t len = 0; len = security_getprocattr(current, "current", NULL, 0); if (len < 0) { if (len != -EINVAL) goto error_path; return; } ctx = kmalloc(len, GFP_KERNEL); if (!ctx) goto error_path; len = security_getprocattr(current, "current", ctx, len); if (len < 0 ) goto error_path; audit_log_format(ab, " subj=%s", ctx); return; error_path: kfree(ctx); audit_panic("error in audit_log_task_context"); return; } 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_dentry, vma->vm_file->f_vfsmnt); break; } vma = vma->vm_next; } up_read(&mm->mmap_sem); } audit_log_task_context(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; const char *tty; /* tsk == current */ context->pid = tsk->pid; context->ppid = sys_getppid(); /* sic. tsk == current in all cases */ context->uid = tsk->uid; context->gid = tsk->gid; context->euid = tsk->euid; context->suid = tsk->suid; context->fsuid = tsk->fsuid; context->egid = tsk->egid; context->sgid = tsk->sgid; context->fsgid = tsk->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); if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name) tty = tsk->signal->tty->name; else tty = "(none)"; 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", context->argv[0], context->argv[1], context->argv[2], context->argv[3], context->name_count, context->ppid, context->pid, context->loginuid, context->uid, context->gid, context->euid, context->suid, context->fsuid, context->egid, context->sgid, context->fsgid, tty); audit_log_task_info(ab, tsk); if (context->filterkey) { audit_log_format(ab, " key="); audit_log_untrustedstring(ab, context->filterkey); } else audit_log_format(ab, " key=(null)"); 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_MQ_OPEN: { struct audit_aux_data_mq_open *axi = (void *)aux; audit_log_format(ab, "oflag=0x%x mode=%#o mq_flags=0x%lx mq_maxmsg=%ld " "mq_msgsize=%ld mq_curmsgs=%ld", axi->oflag, axi->mode, axi->attr.mq_flags, axi->attr.mq_maxmsg, axi->attr.mq_msgsize, axi->attr.mq_curmsgs); break; } case AUDIT_MQ_SENDRECV: { struct audit_aux_data_mq_sendrecv *axi = (void *)aux; audit_log_format(ab, "mqdes=%d msg_len=%zd msg_prio=%u " "abs_timeout_sec=%ld abs_timeout_nsec=%ld", axi->mqdes, axi->msg_len, axi->msg_prio, axi->abs_timeout.tv_sec, axi->abs_timeout.tv_nsec); break; } case AUDIT_MQ_NOTIFY: { struct audit_aux_data_mq_notify *axi = (void *)aux; audit_log_format(ab, "mqdes=%d sigev_signo=%d", axi->mqdes, axi->notification.sigev_signo); break; } case AUDIT_MQ_GETSETATTR: { struct audit_aux_data_mq_getsetattr *axi = (void *)aux; audit_log_format(ab, "mqdes=%d mq_flags=0x%lx mq_maxmsg=%ld mq_msgsize=%ld " "mq_curmsgs=%ld ", axi->mqdes, axi->mqstat.mq_flags, axi->mqstat.mq_maxmsg, axi->mqstat.mq_msgsize, axi->mqstat.mq_curmsgs); break; } case AUDIT_IPC: { struct audit_aux_data_ipcctl *axi = (void *)aux; audit_log_format(ab, "ouid=%u ogid=%u mode=%x", axi->uid, axi->gid, axi->mode); if (axi->osid != 0) { char *ctx = NULL; u32 len; if (selinux_sid_to_string( axi->osid, &ctx, &len)) { audit_log_format(ab, " osid=%u", axi->osid); call_panic = 1; } else audit_log_format(ab, " obj=%s", ctx); kfree(ctx); } break; } case AUDIT_IPC_SET_PERM: { struct audit_aux_data_ipcctl *axi = (void *)aux; audit_log_format(ab, "qbytes=%lx ouid=%u ogid=%u mode=%x", axi->qbytes, axi->uid, axi->gid, axi->mode); break; } case AUDIT_EXECVE: { struct audit_aux_data_execve *axi = (void *)aux; int i; const char *p; for (i = 0, p = axi->mem; i < axi->argc; i++) { audit_log_format(ab, "a%d=", i); p = audit_log_untrustedstring(ab, p); audit_log_format(ab, "\n"); } break; } case AUDIT_SOCKETCALL: { int i; struct audit_aux_data_socketcall *axs = (void *)aux; audit_log_format(ab, "nargs=%d", axs->nargs); for (i=0; i<axs->nargs; i++) audit_log_format(ab, " a%d=%lx", i, axs->args[i]); break; } case AUDIT_SOCKADDR: { struct audit_aux_data_sockaddr *axs = (void *)aux; audit_log_format(ab, "saddr="); audit_log_hex(ab, axs->a, axs->len); break; } case AUDIT_AVC_PATH: { struct audit_aux_data_path *axi = (void *)aux; audit_log_d_path(ab, "path=", axi->dentry, axi->mnt); break; } } audit_log_end(ab); } if (context->pwd && context->pwdmnt) { ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD); if (ab) { audit_log_d_path(ab, "cwd=", context->pwd, context->pwdmnt); audit_log_end(ab); } } for (i = 0; i < context->name_count; i++) { struct audit_names *n = &context->names[i]; ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH); if (!ab) continue; /* audit_panic has been called */ audit_log_format(ab, "item=%d", i); 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, context->pwdmnt); break; default: /* log the name's directory component */ audit_log_format(ab, " name="); audit_log_n_untrustedstring(ab, n->name_len, n->name); } } else audit_log_format(ab, " name=(null)"); if (n->ino != (unsigned long)-1) { audit_log_format(ab, " inode=%lu" " dev=%02x:%02x mode=%#o" " 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 (selinux_sid_to_string( n->osid, &ctx, &len)) { audit_log_format(ab, " osid=%u", n->osid); call_panic = 2; } else audit_log_format(ab, " obj=%s", ctx); kfree(ctx); } 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 (likely(!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->auditable) audit_log_exit(context, tsk); audit_free_context(context); } /** * audit_syscall_entry - fill in an audit record at syscall entry * @tsk: task being audited * @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; BUG_ON(!context); /* * 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_SETUP_CONTEXT || state == AUDIT_BUILD_CONTEXT)) state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_ENTRY]); if (likely(state == AUDIT_DISABLED)) return; context->serial = 0; context->ctime = CURRENT_TIME; context->in_syscall = 1; context->auditable = !!(state == AUDIT_RECORD_CONTEXT); } /** * audit_syscall_exit - deallocate audit context after a system call * @tsk: task being audited * @valid: success/failure flag * @return_code: syscall return value * * 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 write an audit * message), then write out the syscall information. In call cases, * free the names stored from getname(). */ void audit_syscall_exit(int valid, long return_code) { struct task_struct *tsk = current; struct audit_context *context; context = audit_get_context(tsk, valid, return_code); if (likely(!context)) return; if (context->in_syscall && context->auditable) audit_log_exit(context, tsk); context->in_syscall = 0; context->auditable = 0; 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); audit_free_aux(context); kfree(context->filterkey); context->filterkey = NULL; tsk->audit_context = context; } } /** * 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; if (IS_ERR(name) || !name) return; 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; } BUG_ON(context->name_count >= AUDIT_NAMES); context->names[context->name_count].name = name; context->names[context->name_count].name_len = AUDIT_NAME_FULL; context->names[context->name_count].name_put = 1; context->names[context->name_count].ino = (unsigned long)-1; ++context->name_count; if (!context->pwd) { read_lock(¤t->fs->lock); context->pwd = dget(current->fs->pwd); context->pwdmnt = mntget(current->fs->pwdmnt); read_unlock(¤t->fs->lock); } } /* 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) { int i; for (i = 0; i < context->name_count; i++) printk(KERN_ERR "name[%d] = %p = %s\n", i, context->names[i].name, context->names[i].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 } /* Copy inode data into an audit_names. */ static void audit_copy_inode(struct audit_names *name, 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; selinux_get_inode_sid(inode, &name->osid); } /** * audit_inode - store the inode and device from a lookup * @name: name being audited * @inode: inode being audited * * Called from fs/namei.c:path_lookup(). */ void __audit_inode(const char *name, const struct inode *inode) { int idx; struct audit_context *context = current->audit_context; if (!context->in_syscall) return; if (context->name_count && context->names[context->name_count-1].name && context->names[context->name_count-1].name == name) idx = context->name_count - 1; else if (context->name_count > 1 && context->names[context->name_count-2].name && context->names[context->name_count-2].name == name) idx = context->name_count - 2; else { /* FIXME: how much do we care about inodes that have no * associated name? */ if (context->name_count >= AUDIT_NAMES - AUDIT_NAMES_RESERVED) return; idx = context->name_count++; context->names[idx].name = NULL; #if AUDIT_DEBUG ++context->ino_count; #endif } audit_copy_inode(&context->names[idx], inode); } /** * audit_inode_child - collect inode info for created/removed objects * @dname: inode's dentry name * @inode: inode 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 char *dname, const struct inode *inode, const struct inode *parent) { int idx; struct audit_context *context = current->audit_context; const char *found_name = NULL; int dirlen = 0; if (!context->in_syscall) return; /* determine matching parent */ if (!dname) goto update_context; for (idx = 0; idx < context->name_count; idx++) if (context->names[idx].ino == parent->i_ino) { const char *name = context->names[idx].name; if (!name) continue; if (audit_compare_dname_path(dname, name, &dirlen) == 0) { context->names[idx].name_len = dirlen; found_name = name; break; } } update_context: idx = context->name_count++; #if AUDIT_DEBUG context->ino_count++; #endif /* Re-use the name belonging to the slot for a matching parent directory. * All names for this context are relinquished in audit_free_names() */ context->names[idx].name = found_name; context->names[idx].name_len = AUDIT_NAME_FULL; context->names[idx].name_put = 0; /* don't call __putname() */ if (!inode) context->names[idx].ino = (unsigned long)-1; else audit_copy_inode(&context->names[idx], inode); /* A parent was not found in audit_names, so copy the inode data for the * provided parent. */ if (!found_name) { idx = context->name_count++; #if AUDIT_DEBUG context->ino_count++; #endif audit_copy_inode(&context->names[idx], parent); } } /** * audit_inode_update - update inode info for last collected name * @inode: inode being audited * * When open() is called on an existing object with the O_CREAT flag, the inode * data audit initially collects is incorrect. This additional hook ensures * audit has the inode data for the actual object to be opened. */ void __audit_inode_update(const struct inode *inode) { struct audit_context *context = current->audit_context; int idx; if (!context->in_syscall || !inode) return; if (context->name_count == 0) { context->name_count++; #if AUDIT_DEBUG context->ino_count++; #endif } idx = context->name_count - 1; audit_copy_inode(&context->names[idx], inode); } /** * 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. */ void auditsc_get_stamp(struct audit_context *ctx, struct timespec *t, unsigned int *serial) { if (!ctx->serial) ctx->serial = audit_serial(); t->tv_sec = ctx->ctime.tv_sec; t->tv_nsec = ctx->ctime.tv_nsec; *serial = ctx->serial; ctx->auditable = 1; } /** * audit_set_loginuid - set a task's audit_context loginuid * @task: task whose audit context is being modified * @loginuid: loginuid value * * Returns 0. * * Called (set) from fs/proc/base.c::proc_loginuid_write(). */ int audit_set_loginuid(struct task_struct *task, uid_t loginuid) { struct audit_context *context = task->audit_context; if (context) { /* Only log if audit is enabled */ if (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", task->pid, task->uid, context->loginuid, loginuid); audit_log_end(ab); } } context->loginuid = loginuid; } return 0; } /** * audit_get_loginuid - get the loginuid for an audit_context * @ctx: the audit_context * * Returns the context's loginuid or -1 if @ctx is NULL. */ uid_t audit_get_loginuid(struct audit_context *ctx) { return ctx ? ctx->loginuid : -1; } /** * __audit_mq_open - record audit data for a POSIX MQ open * @oflag: open flag * @mode: mode bits * @u_attr: queue attributes * * Returns 0 for success or NULL context or < 0 on error. */ int __audit_mq_open(int oflag, mode_t mode, struct mq_attr __user *u_attr) { struct audit_aux_data_mq_open *ax; struct audit_context *context = current->audit_context; if (!audit_enabled) return 0; if (likely(!context)) return 0; ax = kmalloc(sizeof(*ax), GFP_ATOMIC); if (!ax) return -ENOMEM; if (u_attr != NULL) { if (copy_from_user(&ax->attr, u_attr, sizeof(ax->attr))) { kfree(ax); return -EFAULT; } } else memset(&ax->attr, 0, sizeof(ax->attr)); ax->oflag = oflag; ax->mode = mode; ax->d.type = AUDIT_MQ_OPEN; ax->d.next = context->aux; context->aux = (void *)ax; return 0; } /** * __audit_mq_timedsend - record audit data for a POSIX MQ timed send * @mqdes: MQ descriptor * @msg_len: Message length * @msg_prio: Message priority * @u_abs_timeout: Message timeout in absolute time * * Returns 0 for success or NULL context or < 0 on error. */ int __audit_mq_timedsend(mqd_t mqdes, size_t msg_len, unsigned int msg_prio, const struct timespec __user *u_abs_timeout) { struct audit_aux_data_mq_sendrecv *ax; struct audit_context *context = current->audit_context; if (!audit_enabled) return 0; if (likely(!context)) return 0; ax = kmalloc(sizeof(*ax), GFP_ATOMIC); if (!ax) return -ENOMEM; if (u_abs_timeout != NULL) { if (copy_from_user(&ax->abs_timeout, u_abs_timeout, sizeof(ax->abs_timeout))) { kfree(ax); return -EFAULT; } } else memset(&ax->abs_timeout, 0, sizeof(ax->abs_timeout)); ax->mqdes = mqdes; ax->msg_len = msg_len; ax->msg_prio = msg_prio; ax->d.type = AUDIT_MQ_SENDRECV; ax->d.next = context->aux; context->aux = (void *)ax; return 0; } /** * __audit_mq_timedreceive - record audit data for a POSIX MQ timed receive * @mqdes: MQ descriptor * @msg_len: Message length * @u_msg_prio: Message priority * @u_abs_timeout: Message timeout in absolute time * * Returns 0 for success or NULL context or < 0 on error. */ int __audit_mq_timedreceive(mqd_t mqdes, size_t msg_len, unsigned int __user *u_msg_prio, const struct timespec __user *u_abs_timeout) { struct audit_aux_data_mq_sendrecv *ax; struct audit_context *context = current->audit_context; if (!audit_enabled) return 0; if (likely(!context)) return 0; ax = kmalloc(sizeof(*ax), GFP_ATOMIC); if (!ax) return -ENOMEM; if (u_msg_prio != NULL) { if (get_user(ax->msg_prio, u_msg_prio)) { kfree(ax); return -EFAULT; } } else ax->msg_prio = 0; if (u_abs_timeout != NULL) { if (copy_from_user(&ax->abs_timeout, u_abs_timeout, sizeof(ax->abs_timeout))) { kfree(ax); return -EFAULT; } } else memset(&ax->abs_timeout, 0, sizeof(ax->abs_timeout)); ax->mqdes = mqdes; ax->msg_len = msg_len; ax->d.type = AUDIT_MQ_SENDRECV; ax->d.next = context->aux; context->aux = (void *)ax; return 0; } /** * __audit_mq_notify - record audit data for a POSIX MQ notify * @mqdes: MQ descriptor * @u_notification: Notification event * * Returns 0 for success or NULL context or < 0 on error. */ int __audit_mq_notify(mqd_t mqdes, const struct sigevent __user *u_notification) { struct audit_aux_data_mq_notify *ax; struct audit_context *context = current->audit_context; if (!audit_enabled) return 0; if (likely(!context)) return 0; ax = kmalloc(sizeof(*ax), GFP_ATOMIC); if (!ax) return -ENOMEM; if (u_notification != NULL) { if (copy_from_user(&ax->notification, u_notification, sizeof(ax->notification))) { kfree(ax); return -EFAULT; } } else memset(&ax->notification, 0, sizeof(ax->notification)); ax->mqdes = mqdes; ax->d.type = AUDIT_MQ_NOTIFY; ax->d.next = context->aux; context->aux = (void *)ax; return 0; } /** * __audit_mq_getsetattr - record audit data for a POSIX MQ get/set attribute * @mqdes: MQ descriptor * @mqstat: MQ flags * * Returns 0 for success or NULL context or < 0 on error. */ int __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat) { struct audit_aux_data_mq_getsetattr *ax; struct audit_context *context = current->audit_context; if (!audit_enabled) return 0; if (likely(!context)) return 0; ax = kmalloc(sizeof(*ax), GFP_ATOMIC); if (!ax) return -ENOMEM; ax->mqdes = mqdes; ax->mqstat = *mqstat; ax->d.type = AUDIT_MQ_GETSETATTR; ax->d.next = context->aux; context->aux = (void *)ax; return 0; } /** * audit_ipc_obj - record audit data for ipc object * @ipcp: ipc permissions * * Returns 0 for success or NULL context or < 0 on error. */ int __audit_ipc_obj(struct kern_ipc_perm *ipcp) { struct audit_aux_data_ipcctl *ax; struct audit_context *context = current->audit_context; ax = kmalloc(sizeof(*ax), GFP_ATOMIC); if (!ax) return -ENOMEM; ax->uid = ipcp->uid; ax->gid = ipcp->gid; ax->mode = ipcp->mode; selinux_get_ipc_sid(ipcp, &ax->osid); ax->d.type = AUDIT_IPC; ax->d.next = context->aux; context->aux = (void *)ax; return 0; } /** * 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) * * Returns 0 for success or NULL context or < 0 on error. */ int __audit_ipc_set_perm(unsigned long qbytes, uid_t uid, gid_t gid, mode_t mode) { struct audit_aux_data_ipcctl *ax; struct audit_context *context = current->audit_context; ax = kmalloc(sizeof(*ax), GFP_ATOMIC); if (!ax) return -ENOMEM; ax->qbytes = qbytes; ax->uid = uid; ax->gid = gid; ax->mode = mode; ax->d.type = AUDIT_IPC_SET_PERM; ax->d.next = context->aux; context->aux = (void *)ax; return 0; } int audit_bprm(struct linux_binprm *bprm) { struct audit_aux_data_execve *ax; struct audit_context *context = current->audit_context; unsigned long p, next; void *to; if (likely(!audit_enabled || !context || context->dummy)) return 0; ax = kmalloc(sizeof(*ax) + PAGE_SIZE * MAX_ARG_PAGES - bprm->p, GFP_KERNEL); if (!ax) return -ENOMEM; ax->argc = bprm->argc; ax->envc = bprm->envc; for (p = bprm->p, to = ax->mem; p < MAX_ARG_PAGES*PAGE_SIZE; p = next) { struct page *page = bprm->page[p / PAGE_SIZE]; void *kaddr = kmap(page); next = (p + PAGE_SIZE) & ~(PAGE_SIZE - 1); memcpy(to, kaddr + (p & (PAGE_SIZE - 1)), next - p); to += next - p; kunmap(page); } 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 * * Returns 0 for success or NULL context or < 0 on error. */ int audit_socketcall(int nargs, unsigned long *args) { struct audit_aux_data_socketcall *ax; struct audit_context *context = current->audit_context; if (likely(!context || context->dummy)) return 0; ax = kmalloc(sizeof(*ax) + nargs * sizeof(unsigned long), GFP_KERNEL); if (!ax) return -ENOMEM; ax->nargs = nargs; memcpy(ax->args, args, nargs * sizeof(unsigned long)); ax->d.type = AUDIT_SOCKETCALL; ax->d.next = context->aux; context->aux = (void *)ax; return 0; } /** * 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_aux_data_sockaddr *ax; struct audit_context *context = current->audit_context; if (likely(!context || context->dummy)) return 0; ax = kmalloc(sizeof(*ax) + len, GFP_KERNEL); if (!ax) return -ENOMEM; ax->len = len; memcpy(ax->a, a, len); ax->d.type = AUDIT_SOCKADDR; ax->d.next = context->aux; context->aux = (void *)ax; return 0; } /** * audit_avc_path - record the granting or denial of permissions * @dentry: dentry to record * @mnt: mnt to record * * Returns 0 for success or NULL context or < 0 on error. * * Called from security/selinux/avc.c::avc_audit() */ int audit_avc_path(struct dentry *dentry, struct vfsmount *mnt) { struct audit_aux_data_path *ax; struct audit_context *context = current->audit_context; if (likely(!context)) return 0; ax = kmalloc(sizeof(*ax), GFP_ATOMIC); if (!ax) return -ENOMEM; ax->dentry = dget(dentry); ax->mnt = mntget(mnt); ax->d.type = AUDIT_AVC_PATH; ax->d.next = context->aux; context->aux = (void *)ax; return 0; } /** * 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. */ void __audit_signal_info(int sig, struct task_struct *t) { extern pid_t audit_sig_pid; extern uid_t audit_sig_uid; extern u32 audit_sig_sid; if (sig == SIGTERM || sig == SIGHUP || sig == SIGUSR1) { struct task_struct *tsk = current; struct audit_context *ctx = tsk->audit_context; audit_sig_pid = tsk->pid; if (ctx) audit_sig_uid = ctx->loginuid; else audit_sig_uid = tsk->uid; selinux_get_task_sid(tsk, &audit_sig_sid); } }