diff options
| -rw-r--r-- | include/linux/lsm_hooks.h | 18 | ||||
| -rw-r--r-- | include/linux/security.h | 13 | ||||
| -rw-r--r-- | kernel/sys.c | 30 | ||||
| -rw-r--r-- | security/security.c | 8 | ||||
| -rw-r--r-- | security/selinux/hooks.c | 14 | ||||
| -rw-r--r-- | security/selinux/include/classmap.h | 2 |
6 files changed, 69 insertions, 16 deletions
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index e29d4c62a3c8..ba3049f05aea 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -630,10 +630,19 @@ * Check permission before getting the ioprio value of @p. * @p contains the task_struct of process. * Return 0 if permission is granted. + * @task_prlimit: + * Check permission before getting and/or setting the resource limits of + * another task. + * @cred points to the cred structure for the current task. + * @tcred points to the cred structure for the target task. + * @flags contains the LSM_PRLIMIT_* flag bits indicating whether the + * resource limits are being read, modified, or both. + * Return 0 if permission is granted. * @task_setrlimit: - * Check permission before setting the resource limits of the current - * process for @resource to @new_rlim. The old resource limit values can - * be examined by dereferencing (current->signal->rlim + resource). + * Check permission before setting the resource limits of process @p + * for @resource to @new_rlim. The old resource limit values can + * be examined by dereferencing (p->signal->rlim + resource). + * @p points to the task_struct for the target task's group leader. * @resource contains the resource whose limit is being set. * @new_rlim contains the new limits for @resource. * Return 0 if permission is granted. @@ -1494,6 +1503,8 @@ union security_list_options { int (*task_setnice)(struct task_struct *p, int nice); int (*task_setioprio)(struct task_struct *p, int ioprio); int (*task_getioprio)(struct task_struct *p); + int (*task_prlimit)(const struct cred *cred, const struct cred *tcred, + unsigned int flags); int (*task_setrlimit)(struct task_struct *p, unsigned int resource, struct rlimit *new_rlim); int (*task_setscheduler)(struct task_struct *p); @@ -1755,6 +1766,7 @@ struct security_hook_heads { struct list_head task_setnice; struct list_head task_setioprio; struct list_head task_getioprio; + struct list_head task_prlimit; struct list_head task_setrlimit; struct list_head task_setscheduler; struct list_head task_getscheduler; diff --git a/include/linux/security.h b/include/linux/security.h index 96899fad7016..97df7bac5b48 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -133,6 +133,10 @@ extern unsigned long dac_mmap_min_addr; /* setfsuid or setfsgid, id0 == fsuid or fsgid */ #define LSM_SETID_FS 8 +/* Flags for security_task_prlimit(). */ +#define LSM_PRLIMIT_READ 1 +#define LSM_PRLIMIT_WRITE 2 + /* forward declares to avoid warnings */ struct sched_param; struct request_sock; @@ -324,6 +328,8 @@ void security_task_getsecid(struct task_struct *p, u32 *secid); int security_task_setnice(struct task_struct *p, int nice); int security_task_setioprio(struct task_struct *p, int ioprio); int security_task_getioprio(struct task_struct *p); +int security_task_prlimit(const struct cred *cred, const struct cred *tcred, + unsigned int flags); int security_task_setrlimit(struct task_struct *p, unsigned int resource, struct rlimit *new_rlim); int security_task_setscheduler(struct task_struct *p); @@ -949,6 +955,13 @@ static inline int security_task_getioprio(struct task_struct *p) return 0; } +static inline int security_task_prlimit(const struct cred *cred, + const struct cred *tcred, + unsigned int flags) +{ + return 0; +} + static inline int security_task_setrlimit(struct task_struct *p, unsigned int resource, struct rlimit *new_rlim) diff --git a/kernel/sys.c b/kernel/sys.c index 7ff6d1b10cec..196c7134bee6 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1432,25 +1432,26 @@ out: } /* rcu lock must be held */ -static int check_prlimit_permission(struct task_struct *task) +static int check_prlimit_permission(struct task_struct *task, + unsigned int flags) { const struct cred *cred = current_cred(), *tcred; + bool id_match; if (current == task) return 0; tcred = __task_cred(task); - if (uid_eq(cred->uid, tcred->euid) && - uid_eq(cred->uid, tcred->suid) && - uid_eq(cred->uid, tcred->uid) && - gid_eq(cred->gid, tcred->egid) && - gid_eq(cred->gid, tcred->sgid) && - gid_eq(cred->gid, tcred->gid)) - return 0; - if (ns_capable(tcred->user_ns, CAP_SYS_RESOURCE)) - return 0; + id_match = (uid_eq(cred->uid, tcred->euid) && + uid_eq(cred->uid, tcred->suid) && + uid_eq(cred->uid, tcred->uid) && + gid_eq(cred->gid, tcred->egid) && + gid_eq(cred->gid, tcred->sgid) && + gid_eq(cred->gid, tcred->gid)); + if (!id_match && !ns_capable(tcred->user_ns, CAP_SYS_RESOURCE)) + return -EPERM; - return -EPERM; + return security_task_prlimit(cred, tcred, flags); } SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, @@ -1460,12 +1461,17 @@ SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, struct rlimit64 old64, new64; struct rlimit old, new; struct task_struct *tsk; + unsigned int checkflags = 0; int ret; + if (old_rlim) + checkflags |= LSM_PRLIMIT_READ; + if (new_rlim) { if (copy_from_user(&new64, new_rlim, sizeof(new64))) return -EFAULT; rlim64_to_rlim(&new64, &new); + checkflags |= LSM_PRLIMIT_WRITE; } rcu_read_lock(); @@ -1474,7 +1480,7 @@ SYSCALL_DEFINE4(prlimit64, pid_t, pid, unsigned int, resource, rcu_read_unlock(); return -ESRCH; } - ret = check_prlimit_permission(tsk); + ret = check_prlimit_permission(tsk, checkflags); if (ret) { rcu_read_unlock(); return ret; diff --git a/security/security.c b/security/security.c index d0e07f269b2d..905dad2811d3 100644 --- a/security/security.c +++ b/security/security.c @@ -1036,6 +1036,12 @@ int security_task_getioprio(struct task_struct *p) return call_int_hook(task_getioprio, 0, p); } +int security_task_prlimit(const struct cred *cred, const struct cred *tcred, + unsigned int flags) +{ + return call_int_hook(task_prlimit, 0, cred, tcred, flags); +} + int security_task_setrlimit(struct task_struct *p, unsigned int resource, struct rlimit *new_rlim) { @@ -1793,6 +1799,8 @@ struct security_hook_heads security_hook_heads = { LIST_HEAD_INIT(security_hook_heads.task_setioprio), .task_getioprio = LIST_HEAD_INIT(security_hook_heads.task_getioprio), + .task_prlimit = + LIST_HEAD_INIT(security_hook_heads.task_prlimit), .task_setrlimit = LIST_HEAD_INIT(security_hook_heads.task_setrlimit), .task_setscheduler = diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 0c2ac318aa7f..870d24ecc2de 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3920,6 +3920,19 @@ static int selinux_task_getioprio(struct task_struct *p) PROCESS__GETSCHED, NULL); } +int selinux_task_prlimit(const struct cred *cred, const struct cred *tcred, + unsigned int flags) +{ + u32 av = 0; + + if (flags & LSM_PRLIMIT_WRITE) + av |= PROCESS__SETRLIMIT; + if (flags & LSM_PRLIMIT_READ) + av |= PROCESS__GETRLIMIT; + return avc_has_perm(cred_sid(cred), cred_sid(tcred), + SECCLASS_PROCESS, av, NULL); +} + static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource, struct rlimit *new_rlim) { @@ -6206,6 +6219,7 @@ static struct security_hook_list selinux_hooks[] = { LSM_HOOK_INIT(task_setnice, selinux_task_setnice), LSM_HOOK_INIT(task_setioprio, selinux_task_setioprio), LSM_HOOK_INIT(task_getioprio, selinux_task_getioprio), + LSM_HOOK_INIT(task_prlimit, selinux_task_prlimit), LSM_HOOK_INIT(task_setrlimit, selinux_task_setrlimit), LSM_HOOK_INIT(task_setscheduler, selinux_task_setscheduler), LSM_HOOK_INIT(task_getscheduler, selinux_task_getscheduler), diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h index d429c4a1c551..1e0cc9b5de20 100644 --- a/security/selinux/include/classmap.h +++ b/security/selinux/include/classmap.h @@ -47,7 +47,7 @@ struct security_class_mapping secclass_map[] = { "getattr", "setexec", "setfscreate", "noatsecure", "siginh", "setrlimit", "rlimitinh", "dyntransition", "setcurrent", "execmem", "execstack", "execheap", "setkeycreate", - "setsockcreate", NULL } }, + "setsockcreate", "getrlimit", NULL } }, { "system", { "ipc_info", "syslog_read", "syslog_mod", "syslog_console", "module_request", "module_load", NULL } }, |
