X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=kernel%2Fauditsc.c;h=88696f639aab890140657aba7fcd2956ddfe6623;hb=108150ea78003044e41150c75259447b2c0953b6;hp=74c2ae804ca8baec16a9ee1af48581d087b605e4;hpb=bfb4496e7239c9132d732a65cdcf3d6a7431ad1a;p=linux-2.6 diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 74c2ae804c..88696f639a 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -39,6 +39,9 @@ #include #include #include +#include +#include +#include #include /* 0 = no checking @@ -95,6 +98,7 @@ struct audit_names { uid_t uid; gid_t gid; dev_t rdev; + unsigned flags; }; struct audit_aux_data { @@ -145,6 +149,8 @@ struct audit_context { int auditable; /* 1 if record should be written */ int name_count; struct audit_names names[AUDIT_NAMES]; + struct dentry * pwd; + struct vfsmount * pwdmnt; struct audit_context *previous; /* For nested syscalls */ struct audit_aux_data *aux; @@ -165,9 +171,16 @@ struct audit_context { /* There are three lists of rules -- one to search at task creation * time, one to search at syscall entry time, and another to search at * syscall exit time. */ -static LIST_HEAD(audit_tsklist); -static LIST_HEAD(audit_entlist); -static LIST_HEAD(audit_extlist); +static struct list_head audit_filter_list[AUDIT_NR_FILTERS] = { + LIST_HEAD_INIT(audit_filter_list[0]), + LIST_HEAD_INIT(audit_filter_list[1]), + LIST_HEAD_INIT(audit_filter_list[2]), + LIST_HEAD_INIT(audit_filter_list[3]), + LIST_HEAD_INIT(audit_filter_list[4]), +#if AUDIT_NR_FILTERS != 5 +#error Fix audit_filter_list initialiser +#endif +}; struct audit_entry { struct list_head list; @@ -177,9 +190,36 @@ struct audit_entry { extern int audit_pid; +/* Copy rule from user-space to kernel-space. Called from + * audit_add_rule during AUDIT_ADD. */ +static inline int audit_copy_rule(struct audit_rule *d, struct audit_rule *s) +{ + int i; + + if (s->action != AUDIT_NEVER + && s->action != AUDIT_POSSIBLE + && s->action != AUDIT_ALWAYS) + return -1; + if (s->field_count < 0 || s->field_count > AUDIT_MAX_FIELDS) + return -1; + if ((s->flags & ~AUDIT_FILTER_PREPEND) >= AUDIT_NR_FILTERS) + return -1; + + d->flags = s->flags; + d->action = s->action; + d->field_count = s->field_count; + for (i = 0; i < d->field_count; i++) { + d->fields[i] = s->fields[i]; + d->values[i] = s->values[i]; + } + for (i = 0; i < AUDIT_BITMASK_SIZE; i++) d->mask[i] = s->mask[i]; + return 0; +} + /* Check to see if two rules are identical. It is called from + * audit_add_rule during AUDIT_ADD and * audit_del_rule during AUDIT_DEL. */ -static int audit_compare_rule(struct audit_rule *a, struct audit_rule *b) +static inline int audit_compare_rule(struct audit_rule *a, struct audit_rule *b) { int i; @@ -208,19 +248,37 @@ static int audit_compare_rule(struct audit_rule *a, struct audit_rule *b) /* Note that audit_add_rule and audit_del_rule are called via * audit_receive() in audit.c, and are protected by * audit_netlink_sem. */ -static inline int audit_add_rule(struct audit_entry *entry, - struct list_head *list) +static inline int audit_add_rule(struct audit_rule *rule, + struct list_head *list) { - if (entry->rule.flags & AUDIT_PREPEND) { - entry->rule.flags &= ~AUDIT_PREPEND; + struct audit_entry *entry; + + /* Do not use the _rcu iterator here, since this is the only + * addition routine. */ + list_for_each_entry(entry, list, list) { + if (!audit_compare_rule(rule, &entry->rule)) { + return -EEXIST; + } + } + + if (!(entry = kmalloc(sizeof(*entry), GFP_KERNEL))) + return -ENOMEM; + if (audit_copy_rule(&entry->rule, rule)) { + kfree(entry); + return -EINVAL; + } + + if (entry->rule.flags & AUDIT_FILTER_PREPEND) { + entry->rule.flags &= ~AUDIT_FILTER_PREPEND; list_add_rcu(&entry->list, list); } else { list_add_tail_rcu(&entry->list, list); } + return 0; } -static void audit_free_rule(struct rcu_head *head) +static inline void audit_free_rule(struct rcu_head *head) { struct audit_entry *e = container_of(head, struct audit_entry, rcu); kfree(e); @@ -243,82 +301,82 @@ static inline int audit_del_rule(struct audit_rule *rule, return 0; } } - return -EFAULT; /* No matching rule */ + return -ENOENT; /* No matching rule */ } -/* Copy rule from user-space to kernel-space. Called during - * AUDIT_ADD. */ -static int audit_copy_rule(struct audit_rule *d, struct audit_rule *s) +static int audit_list_rules(void *_dest) { + int pid, seq; + int *dest = _dest; + struct audit_entry *entry; int i; - if (s->action != AUDIT_NEVER - && s->action != AUDIT_POSSIBLE - && s->action != AUDIT_ALWAYS) - return -1; - if (s->field_count < 0 || s->field_count > AUDIT_MAX_FIELDS) - return -1; + pid = dest[0]; + seq = dest[1]; + kfree(dest); - d->flags = s->flags; - d->action = s->action; - d->field_count = s->field_count; - for (i = 0; i < d->field_count; i++) { - d->fields[i] = s->fields[i]; - d->values[i] = s->values[i]; + down(&audit_netlink_sem); + + /* The *_rcu iterators not needed here because we are + always called with audit_netlink_sem held. */ + for (i=0; irule, sizeof(entry->rule)); } - for (i = 0; i < AUDIT_BITMASK_SIZE; i++) d->mask[i] = s->mask[i]; + audit_send_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0); + + up(&audit_netlink_sem); return 0; } int audit_receive_filter(int type, int pid, int uid, int seq, void *data, uid_t loginuid) { - u32 flags; - struct audit_entry *entry; + struct task_struct *tsk; + int *dest; int err = 0; + unsigned listnr; switch (type) { case AUDIT_LIST: - /* The *_rcu iterators not needed here because we are - always called with audit_netlink_sem held. */ - list_for_each_entry(entry, &audit_tsklist, list) - audit_send_reply(pid, seq, AUDIT_LIST, 0, 1, - &entry->rule, sizeof(entry->rule)); - list_for_each_entry(entry, &audit_entlist, list) - audit_send_reply(pid, seq, AUDIT_LIST, 0, 1, - &entry->rule, sizeof(entry->rule)); - list_for_each_entry(entry, &audit_extlist, list) - audit_send_reply(pid, seq, AUDIT_LIST, 0, 1, - &entry->rule, sizeof(entry->rule)); - audit_send_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0); + /* We can't just spew out the rules here because we might fill + * the available socket buffer space and deadlock waiting for + * auditctl to read from it... which isn't ever going to + * happen if we're actually running in the context of auditctl + * trying to _send_ the stuff */ + + dest = kmalloc(2 * sizeof(int), GFP_KERNEL); + if (!dest) + return -ENOMEM; + dest[0] = pid; + dest[1] = seq; + + tsk = kthread_run(audit_list_rules, dest, "audit_list_rules"); + if (IS_ERR(tsk)) { + kfree(dest); + err = PTR_ERR(tsk); + } break; case AUDIT_ADD: - if (!(entry = kmalloc(sizeof(*entry), GFP_KERNEL))) - return -ENOMEM; - if (audit_copy_rule(&entry->rule, data)) { - kfree(entry); + listnr =((struct audit_rule *)data)->flags & ~AUDIT_FILTER_PREPEND; + if (listnr >= AUDIT_NR_FILTERS) return -EINVAL; - } - flags = entry->rule.flags; - if (!err && (flags & AUDIT_PER_TASK)) - err = audit_add_rule(entry, &audit_tsklist); - if (!err && (flags & AUDIT_AT_ENTRY)) - err = audit_add_rule(entry, &audit_entlist); - if (!err && (flags & AUDIT_AT_EXIT)) - err = audit_add_rule(entry, &audit_extlist); - audit_log(NULL, AUDIT_CONFIG_CHANGE, - "auid %u added an audit rule\n", loginuid); + + err = audit_add_rule(data, &audit_filter_list[listnr]); + if (!err) + audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, + "auid=%u added an audit rule\n", loginuid); break; case AUDIT_DEL: - flags =((struct audit_rule *)data)->flags; - if (!err && (flags & AUDIT_PER_TASK)) - err = audit_del_rule(data, &audit_tsklist); - if (!err && (flags & AUDIT_AT_ENTRY)) - err = audit_del_rule(data, &audit_entlist); - if (!err && (flags & AUDIT_AT_EXIT)) - err = audit_del_rule(data, &audit_extlist); - audit_log(NULL, AUDIT_CONFIG_CHANGE, - "auid %u removed an audit rule\n", loginuid); + listnr =((struct audit_rule *)data)->flags & ~AUDIT_FILTER_PREPEND; + if (listnr >= AUDIT_NR_FILTERS) + return -EINVAL; + + err = audit_del_rule(data, &audit_filter_list[listnr]); + if (!err) + audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, + "auid=%u removed an audit rule\n", loginuid); break; default: return -EINVAL; @@ -382,8 +440,12 @@ static int audit_filter_rules(struct task_struct *tsk, result = (ctx->return_code == value); break; case AUDIT_SUCCESS: - if (ctx && ctx->return_valid) - result = (ctx->return_valid == AUDITSC_SUCCESS); + if (ctx && ctx->return_valid) { + if (value) + result = (ctx->return_valid == AUDITSC_SUCCESS); + else + result = (ctx->return_valid == AUDITSC_FAILURE); + } break; case AUDIT_DEVMAJOR: if (ctx) { @@ -452,7 +514,7 @@ static enum audit_state audit_filter_task(struct task_struct *tsk) enum audit_state state; rcu_read_lock(); - list_for_each_entry_rcu(e, &audit_tsklist, list) { + list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TASK], list) { if (audit_filter_rules(tsk, &e->rule, NULL, &state)) { rcu_read_unlock(); return state; @@ -470,22 +532,86 @@ static enum audit_state audit_filter_task(struct task_struct *tsk) 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, &state)) { + rcu_read_unlock(); + return state; + } + } + } + rcu_read_unlock(); + return AUDIT_BUILD_CONTEXT; +} + +static int audit_filter_user_rules(struct netlink_skb_parms *cb, + struct audit_rule *rule, + enum audit_state *state) +{ + int i; + + for (i = 0; i < rule->field_count; i++) { + u32 field = rule->fields[i] & ~AUDIT_NEGATE; + u32 value = rule->values[i]; + int result = 0; + + switch (field) { + case AUDIT_PID: + result = (cb->creds.pid == value); + break; + case AUDIT_UID: + result = (cb->creds.uid == value); + break; + case AUDIT_GID: + result = (cb->creds.gid == value); + break; + case AUDIT_LOGINUID: + result = (cb->loginuid == value); + break; + } + + if (rule->fields[i] & AUDIT_NEGATE) + result = !result; + if (!result) + return 0; + } + switch (rule->action) { + case AUDIT_NEVER: *state = AUDIT_DISABLED; break; + case AUDIT_POSSIBLE: *state = AUDIT_BUILD_CONTEXT; break; + case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break; + } + return 1; +} + +int audit_filter_user(struct netlink_skb_parms *cb, int type) { struct audit_entry *e; enum audit_state state; - int word = AUDIT_WORD(ctx->major); - int bit = AUDIT_BIT(ctx->major); + int ret = 1; rcu_read_lock(); - list_for_each_entry_rcu(e, list, list) { - if ((e->rule.mask[word] & bit) == bit - && audit_filter_rules(tsk, &e->rule, ctx, &state)) { - rcu_read_unlock(); - return state; + list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) { + if (audit_filter_user_rules(cb, &e->rule, &state)) { + if (state == AUDIT_DISABLED) + ret = 0; + break; } } rcu_read_unlock(); - return AUDIT_BUILD_CONTEXT; + + return ret; /* Audit by default */ } /* This should be called with task_lock() held. */ @@ -502,7 +628,7 @@ static inline struct audit_context *audit_get_context(struct task_struct *tsk, if (context->in_syscall && !context->auditable) { enum audit_state state; - state = audit_filter_syscall(tsk, context, &audit_extlist); + state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_EXIT]); if (state == AUDIT_RECORD_CONTEXT) context->auditable = 1; } @@ -552,6 +678,12 @@ static inline void audit_free_names(struct audit_context *context) if (context->names[i].name) __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) @@ -650,7 +782,8 @@ static void audit_log_task_info(struct audit_buffer *ab) struct vm_area_struct *vma; get_task_comm(name, current); - audit_log_format(ab, " comm=%s", name); + audit_log_format(ab, " comm="); + audit_log_untrustedstring(ab, name); if (!mm) return; @@ -670,18 +803,19 @@ static void audit_log_task_info(struct audit_buffer *ab) up_read(&mm->mmap_sem); } -static void audit_log_exit(struct audit_context *context) +static void audit_log_exit(struct audit_context *context, unsigned int gfp_mask) { int i; struct audit_buffer *ab; + struct audit_aux_data *aux; - ab = audit_log_start(context, AUDIT_SYSCALL); + ab = audit_log_start(context, gfp_mask, AUDIT_SYSCALL); if (!ab) return; /* audit_panic has been called */ - audit_log_format(ab, "syscall=%d", context->major); + 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); - audit_log_format(ab, " arch=%x", context->arch); if (context->return_valid) audit_log_format(ab, " success=%s exit=%ld", (context->return_valid==AUDITSC_SUCCESS)?"yes":"no", @@ -704,12 +838,10 @@ static void audit_log_exit(struct audit_context *context) context->egid, context->sgid, context->fsgid); audit_log_task_info(ab); audit_log_end(ab); - while (context->aux) { - struct audit_aux_data *aux; - aux = context->aux; + for (aux = context->aux; aux; aux = aux->next) { - ab = audit_log_start(context, aux->type); + ab = audit_log_start(context, GFP_KERNEL, aux->type); if (!ab) continue; /* audit_panic has been called */ @@ -739,26 +871,31 @@ static void audit_log_exit(struct audit_context *context) case AUDIT_AVC_PATH: { struct audit_aux_data_path *axi = (void *)aux; audit_log_d_path(ab, "path=", axi->dentry, axi->mnt); - dput(axi->dentry); - mntput(axi->mnt); break; } } audit_log_end(ab); - - context->aux = aux->next; - kfree(aux); } + 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++) { - ab = audit_log_start(context, AUDIT_PATH); + 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 (context->names[i].name) { audit_log_format(ab, " name="); audit_log_untrustedstring(ab, context->names[i].name); } + audit_log_format(ab, " flags=%x\n", context->names[i].flags); + if (context->names[i].ino != (unsigned long)-1) audit_log_format(ab, " inode=%lu dev=%02x:%02x mode=%#o" " ouid=%u ogid=%u rdev=%02x:%02x", @@ -788,9 +925,11 @@ void audit_free(struct task_struct *tsk) return; /* Check for system calls that do not go through the exit - * function (e.g., exit_group), then free context block. */ - if (context->in_syscall && context->auditable && context->pid != audit_pid) - audit_log_exit(context); + * 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 */ + if (context->in_syscall && context->auditable) + audit_log_exit(context, GFP_ATOMIC); audit_free_context(context); } @@ -865,11 +1004,11 @@ void audit_syscall_entry(struct task_struct *tsk, int arch, int major, state = context->state; if (state == AUDIT_SETUP_CONTEXT || state == AUDIT_BUILD_CONTEXT) - state = audit_filter_syscall(tsk, context, &audit_entlist); + state = audit_filter_syscall(tsk, context, &audit_filter_list[AUDIT_FILTER_ENTRY]); if (likely(state == AUDIT_DISABLED)) return; - context->serial = audit_serial(); + context->serial = 0; context->ctime = CURRENT_TIME; context->in_syscall = 1; context->auditable = !!(state == AUDIT_RECORD_CONTEXT); @@ -892,10 +1031,10 @@ void audit_syscall_exit(struct task_struct *tsk, int valid, long return_code) /* Not having a context here is ok, since the parent may have * called __put_task_struct. */ if (likely(!context)) - return; + goto out; - if (context->in_syscall && context->auditable && context->pid != audit_pid) - audit_log_exit(context); + if (context->in_syscall && context->auditable) + audit_log_exit(context, GFP_KERNEL); context->in_syscall = 0; context->auditable = 0; @@ -908,9 +1047,9 @@ void audit_syscall_exit(struct task_struct *tsk, int valid, long return_code) } else { audit_free_names(context); audit_free_aux(context); - audit_zero_context(context, context->state); tsk->audit_context = context; } + out: put_task_struct(tsk); } @@ -934,6 +1073,13 @@ void audit_getname(const char *name) context->names[context->name_count].name = name; 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); + } + } /* Intercept a putname request. Called from @@ -978,7 +1124,7 @@ void audit_putname(const char *name) /* Store the inode and device from a lookup. Called from * fs/namei.c:path_lookup(). */ -void audit_inode(const char *name, const struct inode *inode) +void audit_inode(const char *name, const struct inode *inode, unsigned flags) { int idx; struct audit_context *context = current->audit_context; @@ -1004,17 +1150,20 @@ void audit_inode(const char *name, const struct inode *inode) ++context->ino_count; #endif } - context->names[idx].ino = inode->i_ino; - context->names[idx].dev = inode->i_sb->s_dev; - context->names[idx].mode = inode->i_mode; - context->names[idx].uid = inode->i_uid; - context->names[idx].gid = inode->i_gid; - context->names[idx].rdev = inode->i_rdev; + context->names[idx].flags = flags; + context->names[idx].ino = inode->i_ino; + context->names[idx].dev = inode->i_sb->s_dev; + context->names[idx].mode = inode->i_mode; + context->names[idx].uid = inode->i_uid; + context->names[idx].gid = inode->i_gid; + context->names[idx].rdev = inode->i_rdev; } 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; @@ -1026,7 +1175,7 @@ int audit_set_loginuid(struct task_struct *task, uid_t loginuid) if (task->audit_context) { struct audit_buffer *ab; - ab = audit_log_start(NULL, AUDIT_LOGIN); + 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", @@ -1135,7 +1284,7 @@ void audit_signal_info(int sig, struct task_struct *t) extern pid_t audit_sig_pid; extern uid_t audit_sig_uid; - if (unlikely(audit_pid && t->pid == audit_pid)) { + if (unlikely(audit_pid && t->tgid == audit_pid)) { if (sig == SIGTERM || sig == SIGHUP) { struct audit_context *ctx = current->audit_context; audit_sig_pid = current->pid;