Re: audit-ptrace patch (untested)

On Tue, Mar 06, 2007 at 09:46:14AM -0500, Stephen Smalley wrote: OK... Here's combined patch (with switch to security_task_getsecid(), etc.) diff --git a/fs/proc/base.c b/fs/proc/base.c index 4f5745a..6bbfe91 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1558,29 +1558,20 @@ static ssize_t proc_pid_attr_read(struct file * file, char __user * buf, size_t count, loff_t *ppos) { struct inode * inode = file->f_path.dentry->d_inode; - unsigned long page; + char *p = NULL; ssize_t length; struct task_struct *task = get_proc_task(inode); - length = -ESRCH; if (!task) - goto out_no_task; - - if (count > PAGE_SIZE) - count = PAGE_SIZE; - length = -ENOMEM; - if (!(page = __get_free_page(GFP_KERNEL))) - goto out; + return -ESRCH; length = security_getprocattr(task, (char*)file->f_path.dentry->d_name.name, - (void*)page, count); - if (length >= 0) - length = simple_read_from_buffer(buf, count, ppos, (char *)page, length); - free_page(page); -out: + &p); put_task_struct(task); -out_no_task: + if (length > 0) + length = simple_read_from_buffer(buf, count, ppos, p, length); + kfree(p); return length; } diff --git a/include/linux/audit.h b/include/linux/audit.h index 229fa01..31b0f40 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -90,6 +90,7 @@ #define AUDIT_MQ_GETSETATTR 1315 /* POSIX MQ get/set attribute record type */ #define AUDIT_KERNEL_OTHER 1316 /* For use by 3rd party modules */ #define AUDIT_FD_PAIR 1317 /* audit record for pipe/socketpair */ +#define AUDIT_OBJ_PID 1318 /* ptrace target */ #define AUDIT_AVC 1400 /* SE Linux avc denial or grant */ #define AUDIT_SELINUX_ERR 1401 /* Internal SE Linux Errors */ @@ -351,6 +352,8 @@ extern void __audit_inode(const char *name, const struct inode *inode); extern void __audit_inode_child(const char *dname, const struct inode *inode, const struct inode *parent); extern void __audit_inode_update(const struct inode *inode); +extern void __audit_ptrace(struct task_struct *t); + static inline int audit_dummy_context(void) { void *p = current->audit_context; @@ -376,6 +379,12 @@ static inline void audit_inode_update(const struct inode *inode) { __audit_inode_update(inode); } +static inline void audit_ptrace(struct task_struct *t) +{ + if (unlikely(!audit_dummy_context())) + __audit_ptrace(t); +} + /* Private API (for audit.c only) */ extern unsigned int audit_serial(void); extern void auditsc_get_stamp(struct audit_context *ctx, @@ -476,6 +485,7 @@ extern int audit_n_rules; #define audit_mq_timedreceive(d,l,p,t) ({ 0; }) #define audit_mq_notify(d,n) ({ 0; }) #define audit_mq_getsetattr(d,s) ({ 0; }) +#define audit_ptrace(t) ((void)0) #define audit_n_rules 0 #endif diff --git a/include/linux/security.h b/include/linux/security.h index 7f88d97..47e82c1 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -1324,7 +1324,7 @@ struct security_operations { void (*d_instantiate) (struct dentry *dentry, struct inode *inode); - int (*getprocattr)(struct task_struct *p, char *name, void *value, size_t size); + int (*getprocattr)(struct task_struct *p, char *name, char **value); int (*setprocattr)(struct task_struct *p, char *name, void *value, size_t size); int (*secid_to_secctx)(u32 secid, char **secdata, u32 *seclen); void (*release_secctx)(char *secdata, u32 seclen); @@ -2092,9 +2092,9 @@ static inline void security_d_instantiate (struct dentry *dentry, struct inode * security_ops->d_instantiate (dentry, inode); } -static inline int security_getprocattr(struct task_struct *p, char *name, void *value, size_t size) +static inline int security_getprocattr(struct task_struct *p, char *name, char **value) { - return security_ops->getprocattr(p, name, value, size); + return security_ops->getprocattr(p, name, value); } static inline int security_setprocattr(struct task_struct *p, char *name, void *value, size_t size) @@ -2749,7 +2749,7 @@ static inline int security_sem_semop (struct sem_array * sma, static inline void security_d_instantiate (struct dentry *dentry, struct inode *inode) { } -static inline int security_getprocattr(struct task_struct *p, char *name, void *value, size_t size) +static inline int security_getprocattr(struct task_struct *p, char *name, char **value) { return -EINVAL; } diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 3599558..f8875cb 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -209,6 +209,9 @@ struct audit_context { unsigned long personality; int arch; + pid_t target_pid; + char * obj_ctx; + #if AUDIT_DEBUG int put_count; int ino_count; @@ -729,6 +732,7 @@ static inline void audit_free_context(struct audit_context *context) audit_free_names(context); audit_free_aux(context); kfree(context->filterkey); + kfree(context->obj_ctx); kfree(context); context = previous; } while (context); @@ -739,28 +743,26 @@ static inline void audit_free_context(struct audit_context *context) void audit_log_task_context(struct audit_buffer *ab) { char *ctx = NULL; - ssize_t len = 0; + unsigned len; + int error; + u32 sid; - len = security_getprocattr(current, "current", NULL, 0); - if (len < 0) { - if (len != -EINVAL) + 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; } - 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); + kfree(ctx); return; error_path: - kfree(ctx); audit_panic("error in audit_log_task_context"); return; } @@ -975,6 +977,16 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts audit_log_end(ab); } + if (context->target_pid) { + char *s = context->obj_ctx ? context->obj_ctx : "(none)"; + ab =audit_log_start(context, GFP_KERNEL, AUDIT_OBJ_PID); + if (ab) { + audit_log_format(ab, "opid=%d obj=%s", + context->target_pid, s); + audit_log_end(ab); + } + } + if (context->pwd && context->pwdmnt) { ab = audit_log_start(context, GFP_KERNEL, AUDIT_CWD); if (ab) { @@ -1195,6 +1207,9 @@ void audit_syscall_exit(int valid, long return_code) } else { audit_free_names(context); audit_free_aux(context); + kfree(context->obj_ctx); + context->obj_ctx = NULL; + context->target_pid = 0; kfree(context->filterkey); context->filterkey = NULL; tsk->audit_context = context; @@ -1882,6 +1897,19 @@ int audit_sockaddr(int len, void *a) return 0; } +void __audit_ptrace(struct task_struct *t) +{ + struct audit_context *context = current->audit_context; + unsigned len; + u32 sid; + + context->target_pid = t->pid; + + security_task_getsecid(t, &sid); + if (sid) + security_secid_to_secctx(sid, &context->obj_ctx, &len); +} + /** * audit_avc_path - record the granting or denial of permissions * @dentry: dentry to record diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 4d50e06..ad7949a 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -18,6 +18,7 @@ #include <linux/ptrace.h> #include <linux/security.h> #include <linux/signal.h> +#include <linux/audit.h> #include <asm/pgtable.h> #include <asm/uaccess.h> @@ -161,6 +162,8 @@ int ptrace_attach(struct task_struct *task) { int retval; + audit_ptrace(task); + retval = -EPERM; if (task->pid <= 1) goto out; diff --git a/security/dummy.c b/security/dummy.c index 558795b..8ffd764 100644 --- a/security/dummy.c +++ b/security/dummy.c @@ -907,7 +907,7 @@ static void dummy_d_instantiate (struct dentry *dentry, struct inode *inode) return; } -static int dummy_getprocattr(struct task_struct *p, char *name, void *value, size_t size) +static int dummy_getprocattr(struct task_struct *p, char *name, char **value) { return -EINVAL; } diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index b1ac22d..0b265a5 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -4468,11 +4468,12 @@ static void selinux_d_instantiate (struct dentry *dentry, struct inode *inode) } static int selinux_getprocattr(struct task_struct *p, - char *name, void *value, size_t size) + char *name, char **value) { struct task_security_struct *tsec; u32 sid; int error; + unsigned len; if (current != p) { error = task_has_perm(current, p, PROCESS__GETATTR); @@ -4500,7 +4501,10 @@ static int selinux_getprocattr(struct task_struct *p, if (!sid) return 0; - return selinux_getsecurity(sid, value, size); + error = security_sid_to_context(sid, value, &len); + if (error) + return error; + return len; } static int selinux_setprocattr(struct task_struct *p,