diff --git a/arch/mips/include/asm/seccomp.h b/arch/mips/include/asm/seccomp.h index e383d7e27b93..aa809589a181 100644 --- a/arch/mips/include/asm/seccomp.h +++ b/arch/mips/include/asm/seccomp.h @@ -9,12 +9,12 @@ static inline const int *get_compat_mode1_syscalls(void) static const int syscalls_O32[] = { __NR_O32_Linux + 3, __NR_O32_Linux + 4, __NR_O32_Linux + 1, __NR_O32_Linux + 193, - 0, /* null terminated */ + -1, /* negative terminated */ }; static const int syscalls_N32[] = { __NR_N32_Linux + 0, __NR_N32_Linux + 1, __NR_N32_Linux + 58, __NR_N32_Linux + 211, - 0, /* null terminated */ + -1, /* negative terminated */ }; if (IS_ENABLED(CONFIG_MIPS32_O32) && test_thread_flag(TIF_32BIT_REGS)) diff --git a/fs/file.c b/fs/file.c index abb8b7081d7a..4fb111735d1d 100644 --- a/fs/file.c +++ b/fs/file.c @@ -18,6 +18,7 @@ #include #include #include +#include unsigned int sysctl_nr_open __read_mostly = 1024*1024; unsigned int sysctl_nr_open_min = BITS_PER_LONG; @@ -613,6 +614,10 @@ void __fd_install(struct files_struct *files, unsigned int fd, rcu_read_unlock_sched(); } +/* + * This consumes the "file" refcount, so callers should treat it + * as if they had called fput(file). + */ void fd_install(unsigned int fd, struct file *file) { __fd_install(current->files, fd, file); @@ -931,6 +936,62 @@ out_unlock: return err; } +/** + * __receive_fd() - Install received file into file descriptor table + * + * @fd: fd to install into (if negative, a new fd will be allocated) + * @file: struct file that was received from another process + * @ufd: __user pointer to write new fd number to + * @o_flags: the O_* flags to apply to the new fd entry + * + * Installs a received file into the file descriptor table, with appropriate + * checks and count updates. Optionally writes the fd number to userspace, if + * @ufd is non-NULL. + * + * This helper handles its own reference counting of the incoming + * struct file. + * + * Returns newly install fd or -ve on error. + */ +int __receive_fd(int fd, struct file *file, int __user *ufd, unsigned int o_flags) +{ + int new_fd; + int error; + + error = security_file_receive(file); + if (error) + return error; + + if (fd < 0) { + new_fd = get_unused_fd_flags(o_flags); + if (new_fd < 0) + return new_fd; + } else { + new_fd = fd; + } + + if (ufd) { + error = put_user(new_fd, ufd); + if (error) { + if (fd < 0) + put_unused_fd(new_fd); + return error; + } + } + + if (fd < 0) { + fd_install(new_fd, get_file(file)); + } else { + error = replace_fd(new_fd, file, o_flags); + if (error) + return error; + } + + /* Bump the sock usage counts, if any. */ + __receive_sock(file); + return new_fd; +} + static int ksys_dup3(unsigned int oldfd, unsigned int newfd, int flags) { int err = -EBADF; diff --git a/fs/proc/array.c b/fs/proc/array.c index 55ecbeb3a721..65ec2029fa80 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -341,6 +341,8 @@ static inline void task_seccomp(struct seq_file *m, struct task_struct *p) seq_put_decimal_ull(m, "NoNewPrivs:\t", task_no_new_privs(p)); #ifdef CONFIG_SECCOMP seq_put_decimal_ull(m, "\nSeccomp:\t", p->seccomp.mode); + seq_put_decimal_ull(m, "\nSeccomp_filters:\t", + atomic_read(&p->seccomp.filter_count)); #endif seq_puts(m, "\nSpeculation_Store_Bypass:\t"); switch (arch_prctl_spec_ctrl_get(p, PR_SPEC_STORE_BYPASS)) { diff --git a/include/asm-generic/seccomp.h b/include/asm-generic/seccomp.h index 1321ac7821d7..6b6f42bc58f9 100644 --- a/include/asm-generic/seccomp.h +++ b/include/asm-generic/seccomp.h @@ -33,7 +33,7 @@ static inline const int *get_compat_mode1_syscalls(void) static const int mode1_syscalls_32[] = { __NR_seccomp_read_32, __NR_seccomp_write_32, __NR_seccomp_exit_32, __NR_seccomp_sigreturn_32, - 0, /* null terminated */ + -1, /* negative terminated */ }; return mode1_syscalls_32; } diff --git a/include/linux/file.h b/include/linux/file.h index 122f80084a3e..225982792fa2 100644 --- a/include/linux/file.h +++ b/include/linux/file.h @@ -9,6 +9,7 @@ #include #include #include +#include struct file; @@ -91,6 +92,24 @@ extern void put_unused_fd(unsigned int fd); extern void fd_install(unsigned int fd, struct file *file); +extern int __receive_fd(int fd, struct file *file, int __user *ufd, + unsigned int o_flags); +static inline int receive_fd_user(struct file *file, int __user *ufd, + unsigned int o_flags) +{ + if (ufd == NULL) + return -EFAULT; + return __receive_fd(-1, file, ufd, o_flags); +} +static inline int receive_fd(struct file *file, unsigned int o_flags) +{ + return __receive_fd(-1, file, NULL, o_flags); +} +static inline int receive_fd_replace(int fd, struct file *file, unsigned int o_flags) +{ + return __receive_fd(fd, file, NULL, o_flags); +} + extern void flush_delayed_fput(void); extern void __fput_sync(struct file *); diff --git a/include/linux/seccomp.h b/include/linux/seccomp.h index 4192369b8418..881c90b6aa25 100644 --- a/include/linux/seccomp.h +++ b/include/linux/seccomp.h @@ -10,9 +10,14 @@ SECCOMP_FILTER_FLAG_NEW_LISTENER | \ SECCOMP_FILTER_FLAG_TSYNC_ESRCH) +/* sizeof() the first published struct seccomp_notif_addfd */ +#define SECCOMP_NOTIFY_ADDFD_SIZE_VER0 24 +#define SECCOMP_NOTIFY_ADDFD_SIZE_LATEST SECCOMP_NOTIFY_ADDFD_SIZE_VER0 + #ifdef CONFIG_SECCOMP #include +#include #include struct seccomp_filter; @@ -29,6 +34,7 @@ struct seccomp_filter; */ struct seccomp { int mode; + atomic_t filter_count; struct seccomp_filter *filter; }; @@ -82,10 +88,10 @@ static inline int seccomp_mode(struct seccomp *s) #endif /* CONFIG_SECCOMP */ #ifdef CONFIG_SECCOMP_FILTER -extern void put_seccomp_filter(struct task_struct *tsk); +extern void seccomp_filter_release(struct task_struct *tsk); extern void get_seccomp_filter(struct task_struct *tsk); #else /* CONFIG_SECCOMP_FILTER */ -static inline void put_seccomp_filter(struct task_struct *tsk) +static inline void seccomp_filter_release(struct task_struct *tsk) { return; } diff --git a/include/net/sock.h b/include/net/sock.h index 1183507df95b..d05a2c3ed3a6 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -891,6 +891,8 @@ static inline int sk_memalloc_socks(void) { return static_branch_unlikely(&memalloc_socks_key); } + +void __receive_sock(struct file *file); #else static inline int sk_memalloc_socks(void) @@ -898,6 +900,8 @@ static inline int sk_memalloc_socks(void) return 0; } +static inline void __receive_sock(struct file *file) +{ } #endif static inline gfp_t sk_gfp_mask(const struct sock *sk, gfp_t gfp_mask) diff --git a/include/uapi/linux/seccomp.h b/include/uapi/linux/seccomp.h index c1735455bc53..6ba18b82a02e 100644 --- a/include/uapi/linux/seccomp.h +++ b/include/uapi/linux/seccomp.h @@ -113,6 +113,25 @@ struct seccomp_notif_resp { __u32 flags; }; +/* valid flags for seccomp_notif_addfd */ +#define SECCOMP_ADDFD_FLAG_SETFD (1UL << 0) /* Specify remote fd */ + +/** + * struct seccomp_notif_addfd + * @id: The ID of the seccomp notification + * @flags: SECCOMP_ADDFD_FLAG_* + * @srcfd: The local fd number + * @newfd: Optional remote FD number if SETFD option is set, otherwise 0. + * @newfd_flags: The O_* flags the remote FD should have applied + */ +struct seccomp_notif_addfd { + __u64 id; + __u32 flags; + __u32 srcfd; + __u32 newfd; + __u32 newfd_flags; +}; + #define SECCOMP_IOC_MAGIC '!' #define SECCOMP_IO(nr) _IO(SECCOMP_IOC_MAGIC, nr) #define SECCOMP_IOR(nr, type) _IOR(SECCOMP_IOC_MAGIC, nr, type) @@ -123,5 +142,9 @@ struct seccomp_notif_resp { #define SECCOMP_IOCTL_NOTIF_RECV SECCOMP_IOWR(0, struct seccomp_notif) #define SECCOMP_IOCTL_NOTIF_SEND SECCOMP_IOWR(1, \ struct seccomp_notif_resp) -#define SECCOMP_IOCTL_NOTIF_ID_VALID SECCOMP_IOR(2, __u64) +#define SECCOMP_IOCTL_NOTIF_ID_VALID SECCOMP_IOW(2, __u64) +/* On success, the return value is the remote process's added fd number */ +#define SECCOMP_IOCTL_NOTIF_ADDFD SECCOMP_IOW(3, \ + struct seccomp_notif_addfd) + #endif /* _UAPI_LINUX_SECCOMP_H */ diff --git a/init/init_task.c b/init/init_task.c index 15089d15010a..a3eb3847e1f4 100644 --- a/init/init_task.c +++ b/init/init_task.c @@ -204,6 +204,9 @@ struct task_struct init_task #ifdef CONFIG_SECURITY .security = NULL, #endif +#ifdef CONFIG_SECCOMP + .seccomp = { .filter_count = ATOMIC_INIT(0) }, +#endif }; EXPORT_SYMBOL(init_task); diff --git a/kernel/exit.c b/kernel/exit.c index 7bcd571618dd..08b7ffdd0f18 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -217,6 +217,7 @@ repeat: } write_unlock_irq(&tasklist_lock); + seccomp_filter_release(p); proc_flush_pid(thread_pid); put_pid(thread_pid); release_thread(p); diff --git a/kernel/fork.c b/kernel/fork.c index 2a8e7287a558..c1022532a94d 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -479,7 +479,6 @@ void free_task(struct task_struct *tsk) #endif rt_mutex_debug_task_free(tsk); ftrace_graph_exit_task(tsk); - put_seccomp_filter(tsk); arch_release_task_struct(tsk); if (tsk->flags & PF_KTHREAD) free_kthread_struct(tsk); diff --git a/kernel/pid.c b/kernel/pid.c index f1496b757162..da5aea5f04fa 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -42,6 +42,7 @@ #include #include #include +#include struct pid init_struct_pid = { .count = REFCOUNT_INIT(1), @@ -635,17 +636,8 @@ static int pidfd_getfd(struct pid *pid, int fd) if (IS_ERR(file)) return PTR_ERR(file); - ret = security_file_receive(file); - if (ret) { - fput(file); - return ret; - } - - ret = get_unused_fd_flags(O_CLOEXEC); - if (ret < 0) - fput(file); - else - fd_install(ret, file); + ret = receive_fd(file, O_CLOEXEC); + fput(file); return ret; } diff --git a/kernel/seccomp.c b/kernel/seccomp.c index d653d8426de9..3ee59ce0a323 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -13,6 +13,7 @@ * Mode 2 allows user-defined system call filters in the form * of Berkeley Packet Filters/Linux Socket Filters. */ +#define pr_fmt(fmt) "seccomp: " fmt #include #include @@ -41,6 +42,15 @@ #include #include #include +#include + +/* + * When SECCOMP_IOCTL_NOTIF_ID_VALID was first introduced, it had the + * wrong direction flag in the ioctl number. This is the broken one, + * which the kernel needs to keep supporting until all userspaces stop + * using the wrong command number. + */ +#define SECCOMP_IOCTL_NOTIF_ID_VALID_WRONG_DIR SECCOMP_IOR(2, __u64) enum notify_state { SECCOMP_NOTIFY_INIT, @@ -77,10 +87,42 @@ struct seccomp_knotif { long val; u32 flags; - /* Signals when this has entered SECCOMP_NOTIFY_REPLIED */ + /* + * Signals when this has changed states, such as the listener + * dying, a new seccomp addfd message, or changing to REPLIED + */ struct completion ready; struct list_head list; + + /* outstanding addfd requests */ + struct list_head addfd; +}; + +/** + * struct seccomp_kaddfd - container for seccomp_addfd ioctl messages + * + * @file: A reference to the file to install in the other task + * @fd: The fd number to install it at. If the fd number is -1, it means the + * installing process should allocate the fd as normal. + * @flags: The flags for the new file descriptor. At the moment, only O_CLOEXEC + * is allowed. + * @ret: The return value of the installing process. It is set to the fd num + * upon success (>= 0). + * @completion: Indicates that the installing process has completed fd + * installation, or gone away (either due to successful + * reply, or signal) + * + */ +struct seccomp_kaddfd { + struct file *file; + int fd; + unsigned int flags; + + /* To only be set on reply */ + int ret; + struct completion completion; + struct list_head list; }; /** @@ -94,27 +136,35 @@ struct seccomp_knotif { * filter->notify_lock. * @next_id: The id of the next request. * @notifications: A list of struct seccomp_knotif elements. - * @wqh: A wait queue for poll. */ struct notification { struct semaphore request; u64 next_id; struct list_head notifications; - wait_queue_head_t wqh; }; /** * struct seccomp_filter - container for seccomp BPF programs * - * @usage: reference count to manage the object lifetime. - * get/put helpers should be used when accessing an instance - * outside of a lifetime-guarded section. In general, this - * is only needed for handling filters shared across tasks. + * @refs: Reference count to manage the object lifetime. + * A filter's reference count is incremented for each directly + * attached task, once for the dependent filter, and if + * requested for the user notifier. When @refs reaches zero, + * the filter can be freed. + * @users: A filter's @users count is incremented for each directly + * attached task (filter installation, fork(), thread_sync), + * and once for the dependent filter (tracked in filter->prev). + * When it reaches zero it indicates that no direct or indirect + * users of that filter exist. No new tasks can get associated with + * this filter after reaching 0. The @users count is always smaller + * or equal to @refs. Hence, reaching 0 for @users does not mean + * the filter can be freed. * @log: true if all actions except for SECCOMP_RET_ALLOW should be logged * @prev: points to a previously installed, or inherited, filter * @prog: the BPF program to evaluate * @notif: the struct that holds all notification related information * @notify_lock: A lock for all notification-related accesses. + * @wqh: A wait queue for poll if a notifier is in use. * * seccomp_filter objects are organized in a tree linked via the @prev * pointer. For any task, it appears to be a singly-linked list starting @@ -124,15 +174,17 @@ struct notification { * how namespaces work. * * seccomp_filter objects should never be modified after being attached - * to a task_struct (other than @usage). + * to a task_struct (other than @refs). */ struct seccomp_filter { - refcount_t usage; + refcount_t refs; + refcount_t users; bool log; struct seccomp_filter *prev; struct bpf_prog *prog; struct notification *notif; struct mutex notify_lock; + wait_queue_head_t wqh; }; /* Limit any path through the tree to 256KB worth of instructions. */ @@ -366,6 +418,59 @@ static inline pid_t seccomp_can_sync_threads(void) return 0; } +static inline void seccomp_filter_free(struct seccomp_filter *filter) +{ + if (filter) { + bpf_prog_destroy(filter->prog); + kfree(filter); + } +} + +static void __seccomp_filter_orphan(struct seccomp_filter *orig) +{ + while (orig && refcount_dec_and_test(&orig->users)) { + if (waitqueue_active(&orig->wqh)) + wake_up_poll(&orig->wqh, EPOLLHUP); + orig = orig->prev; + } +} + +static void __put_seccomp_filter(struct seccomp_filter *orig) +{ + /* Clean up single-reference branches iteratively. */ + while (orig && refcount_dec_and_test(&orig->refs)) { + struct seccomp_filter *freeme = orig; + orig = orig->prev; + seccomp_filter_free(freeme); + } +} + +static void __seccomp_filter_release(struct seccomp_filter *orig) +{ + /* Notify about any unused filters in the task's former filter tree. */ + __seccomp_filter_orphan(orig); + /* Finally drop all references to the task's former tree. */ + __put_seccomp_filter(orig); +} + +/** + * seccomp_filter_release - Detach the task from its filter tree, + * drop its reference count, and notify + * about unused filters + * + * This function should only be called when the task is exiting as + * it detaches it from its filter tree. As such, READ_ONCE() and + * barriers are not needed here, as would normally be needed. + */ +void seccomp_filter_release(struct task_struct *tsk) +{ + struct seccomp_filter *orig = tsk->seccomp.filter; + + /* Detach task from its filter tree. */ + tsk->seccomp.filter = NULL; + __seccomp_filter_release(orig); +} + /** * seccomp_sync_threads: sets all threads to use current's filter * @@ -390,14 +495,19 @@ static inline void seccomp_sync_threads(unsigned long flags) /* Get a task reference for the new leaf node. */ get_seccomp_filter(caller); + /* * Drop the task reference to the shared ancestor since * current's path will hold a reference. (This also * allows a put before the assignment.) */ - put_seccomp_filter(thread); + __seccomp_filter_release(thread->seccomp.filter); + + /* Make our new filter tree visible. */ smp_store_release(&thread->seccomp.filter, caller->seccomp.filter); + atomic_set(&thread->seccomp.filter_count, + atomic_read(&thread->seccomp.filter_count)); /* * Don't let an unprivileged task work around @@ -461,7 +571,9 @@ static struct seccomp_filter *seccomp_prepare_filter(struct sock_fprog *fprog) return ERR_PTR(ret); } - refcount_set(&sfilter->usage, 1); + refcount_set(&sfilter->refs, 1); + refcount_set(&sfilter->users, 1); + init_waitqueue_head(&sfilter->wqh); return sfilter; } @@ -544,6 +656,7 @@ static long seccomp_attach_filter(unsigned int flags, */ filter->prev = current->seccomp.filter; current->seccomp.filter = filter; + atomic_inc(¤t->seccomp.filter_count); /* Now that the new filter is in place, synchronize to all threads. */ if (flags & SECCOMP_FILTER_FLAG_TSYNC) @@ -554,7 +667,7 @@ static long seccomp_attach_filter(unsigned int flags, static void __get_seccomp_filter(struct seccomp_filter *filter) { - refcount_inc(&filter->usage); + refcount_inc(&filter->refs); } /* get_seccomp_filter - increments the reference count of the filter on @tsk */ @@ -564,30 +677,7 @@ void get_seccomp_filter(struct task_struct *tsk) if (!orig) return; __get_seccomp_filter(orig); -} - -static inline void seccomp_filter_free(struct seccomp_filter *filter) -{ - if (filter) { - bpf_prog_destroy(filter->prog); - kfree(filter); - } -} - -static void __put_seccomp_filter(struct seccomp_filter *orig) -{ - /* Clean up single-reference branches iteratively. */ - while (orig && refcount_dec_and_test(&orig->usage)) { - struct seccomp_filter *freeme = orig; - orig = orig->prev; - seccomp_filter_free(freeme); - } -} - -/* put_seccomp_filter - decrements the ref count of tsk->seccomp.filter */ -void put_seccomp_filter(struct task_struct *tsk) -{ - __put_seccomp_filter(tsk->seccomp.filter); + refcount_inc(&orig->users); } static void seccomp_init_siginfo(kernel_siginfo_t *info, int syscall, int reason) @@ -684,20 +774,20 @@ static inline void seccomp_log(unsigned long syscall, long signr, u32 action, */ static const int mode1_syscalls[] = { __NR_seccomp_read, __NR_seccomp_write, __NR_seccomp_exit, __NR_seccomp_sigreturn, - 0, /* null terminated */ + -1, /* negative terminated */ }; static void __secure_computing_strict(int this_syscall) { - const int *syscall_whitelist = mode1_syscalls; + const int *allowed_syscalls = mode1_syscalls; #ifdef CONFIG_COMPAT if (in_compat_syscall()) - syscall_whitelist = get_compat_mode1_syscalls(); + allowed_syscalls = get_compat_mode1_syscalls(); #endif do { - if (*syscall_whitelist == this_syscall) + if (*allowed_syscalls == this_syscall) return; - } while (*++syscall_whitelist); + } while (*++allowed_syscalls != -1); #ifdef SECCOMP_DEBUG dump_stack(); @@ -735,6 +825,17 @@ static u64 seccomp_next_notify_id(struct seccomp_filter *filter) return filter->notif->next_id++; } +static void seccomp_handle_addfd(struct seccomp_kaddfd *addfd) +{ + /* + * Remove the notification, and reset the list pointers, indicating + * that it has been handled. + */ + list_del_init(&addfd->list); + addfd->ret = receive_fd_replace(addfd->fd, addfd->file, addfd->flags); + complete(&addfd->completion); +} + static int seccomp_do_user_notification(int this_syscall, struct seccomp_filter *match, const struct seccomp_data *sd) @@ -743,6 +844,7 @@ static int seccomp_do_user_notification(int this_syscall, u32 flags = 0; long ret = 0; struct seccomp_knotif n = {}; + struct seccomp_kaddfd *addfd, *tmp; mutex_lock(&match->notify_lock); err = -ENOSYS; @@ -755,25 +857,43 @@ static int seccomp_do_user_notification(int this_syscall, n.id = seccomp_next_notify_id(match); init_completion(&n.ready); list_add(&n.list, &match->notif->notifications); + INIT_LIST_HEAD(&n.addfd); up(&match->notif->request); - wake_up_poll(&match->notif->wqh, EPOLLIN | EPOLLRDNORM); + wake_up_poll(&match->wqh, EPOLLIN | EPOLLRDNORM); mutex_unlock(&match->notify_lock); /* * This is where we wait for a reply from userspace. */ +wait: err = wait_for_completion_interruptible(&n.ready); mutex_lock(&match->notify_lock); if (err == 0) { + /* Check if we were woken up by a addfd message */ + addfd = list_first_entry_or_null(&n.addfd, + struct seccomp_kaddfd, list); + if (addfd && n.state != SECCOMP_NOTIFY_REPLIED) { + seccomp_handle_addfd(addfd); + mutex_unlock(&match->notify_lock); + goto wait; + } ret = n.val; err = n.error; flags = n.flags; } + /* If there were any pending addfd calls, clear them out */ + list_for_each_entry_safe(addfd, tmp, &n.addfd, list) { + /* The process went away before we got a chance to handle it */ + addfd->ret = -ESRCH; + list_del_init(&addfd->list); + complete(&addfd->completion); + } + /* * Note that it's possible the listener died in between the time when - * we were notified of a respons (or a signal) and when we were able to + * we were notified of a response (or a signal) and when we were able to * re-acquire the lock, so only delete from the list if the * notification actually exists. * @@ -1011,6 +1131,11 @@ static int seccomp_notify_release(struct inode *inode, struct file *file) knotif->error = -ENOSYS; knotif->val = 0; + /* + * We do not need to wake up any pending addfd messages, as + * the notifier will do that for us, as this just looks + * like a standard reply. + */ complete(&knotif->ready); } @@ -1021,6 +1146,23 @@ static int seccomp_notify_release(struct inode *inode, struct file *file) return 0; } +/* must be called with notif_lock held */ +static inline struct seccomp_knotif * +find_notification(struct seccomp_filter *filter, u64 id) +{ + struct seccomp_knotif *cur; + + lockdep_assert_held(&filter->notify_lock); + + list_for_each_entry(cur, &filter->notif->notifications, list) { + if (cur->id == id) + return cur; + } + + return NULL; +} + + static long seccomp_notify_recv(struct seccomp_filter *filter, void __user *buf) { @@ -1064,7 +1206,7 @@ static long seccomp_notify_recv(struct seccomp_filter *filter, unotif.data = *(knotif->data); knotif->state = SECCOMP_NOTIFY_SENT; - wake_up_poll(&filter->notif->wqh, EPOLLOUT | EPOLLWRNORM); + wake_up_poll(&filter->wqh, EPOLLOUT | EPOLLWRNORM); ret = 0; out: mutex_unlock(&filter->notify_lock); @@ -1078,15 +1220,8 @@ out: * may have died when we released the lock, so we need to make * sure it's still around. */ - knotif = NULL; mutex_lock(&filter->notify_lock); - list_for_each_entry(cur, &filter->notif->notifications, list) { - if (cur->id == unotif.id) { - knotif = cur; - break; - } - } - + knotif = find_notification(filter, unotif.id); if (knotif) { knotif->state = SECCOMP_NOTIFY_INIT; up(&filter->notif->request); @@ -1101,7 +1236,7 @@ static long seccomp_notify_send(struct seccomp_filter *filter, void __user *buf) { struct seccomp_notif_resp resp = {}; - struct seccomp_knotif *knotif = NULL, *cur; + struct seccomp_knotif *knotif; long ret; if (copy_from_user(&resp, buf, sizeof(resp))) @@ -1118,13 +1253,7 @@ static long seccomp_notify_send(struct seccomp_filter *filter, if (ret < 0) return ret; - list_for_each_entry(cur, &filter->notif->notifications, list) { - if (cur->id == resp.id) { - knotif = cur; - break; - } - } - + knotif = find_notification(filter, resp.id); if (!knotif) { ret = -ENOENT; goto out; @@ -1150,7 +1279,7 @@ out: static long seccomp_notify_id_valid(struct seccomp_filter *filter, void __user *buf) { - struct seccomp_knotif *knotif = NULL; + struct seccomp_knotif *knotif; u64 id; long ret; @@ -1161,17 +1290,109 @@ static long seccomp_notify_id_valid(struct seccomp_filter *filter, if (ret < 0) return ret; - ret = -ENOENT; - list_for_each_entry(knotif, &filter->notif->notifications, list) { - if (knotif->id == id) { - if (knotif->state == SECCOMP_NOTIFY_SENT) - ret = 0; - goto out; - } + knotif = find_notification(filter, id); + if (knotif && knotif->state == SECCOMP_NOTIFY_SENT) + ret = 0; + else + ret = -ENOENT; + + mutex_unlock(&filter->notify_lock); + return ret; +} + +static long seccomp_notify_addfd(struct seccomp_filter *filter, + struct seccomp_notif_addfd __user *uaddfd, + unsigned int size) +{ + struct seccomp_notif_addfd addfd; + struct seccomp_knotif *knotif; + struct seccomp_kaddfd kaddfd; + int ret; + + BUILD_BUG_ON(sizeof(addfd) < SECCOMP_NOTIFY_ADDFD_SIZE_VER0); + BUILD_BUG_ON(sizeof(addfd) != SECCOMP_NOTIFY_ADDFD_SIZE_LATEST); + + if (size < SECCOMP_NOTIFY_ADDFD_SIZE_VER0 || size >= PAGE_SIZE) + return -EINVAL; + + ret = copy_struct_from_user(&addfd, sizeof(addfd), uaddfd, size); + if (ret) + return ret; + + if (addfd.newfd_flags & ~O_CLOEXEC) + return -EINVAL; + + if (addfd.flags & ~SECCOMP_ADDFD_FLAG_SETFD) + return -EINVAL; + + if (addfd.newfd && !(addfd.flags & SECCOMP_ADDFD_FLAG_SETFD)) + return -EINVAL; + + kaddfd.file = fget(addfd.srcfd); + if (!kaddfd.file) + return -EBADF; + + kaddfd.flags = addfd.newfd_flags; + kaddfd.fd = (addfd.flags & SECCOMP_ADDFD_FLAG_SETFD) ? + addfd.newfd : -1; + init_completion(&kaddfd.completion); + + ret = mutex_lock_interruptible(&filter->notify_lock); + if (ret < 0) + goto out; + + knotif = find_notification(filter, addfd.id); + if (!knotif) { + ret = -ENOENT; + goto out_unlock; } -out: + /* + * We do not want to allow for FD injection to occur before the + * notification has been picked up by a userspace handler, or after + * the notification has been replied to. + */ + if (knotif->state != SECCOMP_NOTIFY_SENT) { + ret = -EINPROGRESS; + goto out_unlock; + } + + list_add(&kaddfd.list, &knotif->addfd); + complete(&knotif->ready); mutex_unlock(&filter->notify_lock); + + /* Now we wait for it to be processed or be interrupted */ + ret = wait_for_completion_interruptible(&kaddfd.completion); + if (ret == 0) { + /* + * We had a successful completion. The other side has already + * removed us from the addfd queue, and + * wait_for_completion_interruptible has a memory barrier upon + * success that lets us read this value directly without + * locking. + */ + ret = kaddfd.ret; + goto out; + } + + mutex_lock(&filter->notify_lock); + /* + * Even though we were woken up by a signal and not a successful + * completion, a completion may have happened in the mean time. + * + * We need to check again if the addfd request has been handled, + * and if not, we will remove it from the queue. + */ + if (list_empty(&kaddfd.list)) + ret = kaddfd.ret; + else + list_del(&kaddfd.list); + +out_unlock: + mutex_unlock(&filter->notify_lock); +out: + fput(kaddfd.file); + return ret; } @@ -1181,13 +1402,22 @@ static long seccomp_notify_ioctl(struct file *file, unsigned int cmd, struct seccomp_filter *filter = file->private_data; void __user *buf = (void __user *)arg; + /* Fixed-size ioctls */ switch (cmd) { case SECCOMP_IOCTL_NOTIF_RECV: return seccomp_notify_recv(filter, buf); case SECCOMP_IOCTL_NOTIF_SEND: return seccomp_notify_send(filter, buf); + case SECCOMP_IOCTL_NOTIF_ID_VALID_WRONG_DIR: case SECCOMP_IOCTL_NOTIF_ID_VALID: return seccomp_notify_id_valid(filter, buf); + } + + /* Extensible Argument ioctls */ +#define EA_IOCTL(cmd) ((cmd) & ~(IOC_INOUT | IOCSIZE_MASK)) + switch (EA_IOCTL(cmd)) { + case EA_IOCTL(SECCOMP_IOCTL_NOTIF_ADDFD): + return seccomp_notify_addfd(filter, buf, _IOC_SIZE(cmd)); default: return -EINVAL; } @@ -1200,7 +1430,7 @@ static __poll_t seccomp_notify_poll(struct file *file, __poll_t ret = 0; struct seccomp_knotif *cur; - poll_wait(file, &filter->notif->wqh, poll_tab); + poll_wait(file, &filter->wqh, poll_tab); if (mutex_lock_interruptible(&filter->notify_lock) < 0) return EPOLLERR; @@ -1216,6 +1446,9 @@ static __poll_t seccomp_notify_poll(struct file *file, mutex_unlock(&filter->notify_lock); + if (refcount_read(&filter->users) == 0) + ret |= EPOLLHUP; + return ret; } @@ -1244,7 +1477,6 @@ static struct file *init_listener(struct seccomp_filter *filter) sema_init(&filter->notif->request, 0); filter->notif->next_id = get_random_u64(); INIT_LIST_HEAD(&filter->notif->notifications); - init_waitqueue_head(&filter->notif->wqh); ret = anon_inode_getfile("seccomp notify", &seccomp_notify_ops, filter, O_RDWR); @@ -1822,7 +2054,7 @@ static int __init seccomp_sysctl_init(void) hdr = register_sysctl_paths(seccomp_sysctl_path, seccomp_sysctl_table); if (!hdr) - pr_warn("seccomp: sysctl registration failed\n"); + pr_warn("sysctl registration failed\n"); else kmemleak_not_leak(hdr); diff --git a/net/compat.c b/net/compat.c index 434838bef5f8..77f3a0e98fd0 100644 --- a/net/compat.c +++ b/net/compat.c @@ -281,39 +281,31 @@ int put_cmsg_compat(struct msghdr *kmsg, int level, int type, int len, void *dat return 0; } -void scm_detach_fds_compat(struct msghdr *kmsg, struct scm_cookie *scm) +static int scm_max_fds_compat(struct msghdr *msg) { - struct compat_cmsghdr __user *cm = (struct compat_cmsghdr __user *) kmsg->msg_control; - int fdmax = (kmsg->msg_controllen - sizeof(struct compat_cmsghdr)) / sizeof(int); - int fdnum = scm->fp->count; - struct file **fp = scm->fp->fp; - int __user *cmfptr; + if (msg->msg_controllen <= sizeof(struct compat_cmsghdr)) + return 0; + return (msg->msg_controllen - sizeof(struct compat_cmsghdr)) / sizeof(int); +} + +void scm_detach_fds_compat(struct msghdr *msg, struct scm_cookie *scm) +{ + struct compat_cmsghdr __user *cm = + (struct compat_cmsghdr __user *)msg->msg_control; + unsigned int o_flags = (msg->msg_flags & MSG_CMSG_CLOEXEC) ? O_CLOEXEC : 0; + int fdmax = min_t(int, scm_max_fds_compat(msg), scm->fp->count); + int __user *cmsg_data = CMSG_USER_DATA(cm); int err = 0, i; - if (fdnum < fdmax) - fdmax = fdnum; - - for (i = 0, cmfptr = (int __user *) CMSG_COMPAT_DATA(cm); i < fdmax; i++, cmfptr++) { - int new_fd; - err = security_file_receive(fp[i]); - if (err) - break; - err = get_unused_fd_flags(MSG_CMSG_CLOEXEC & kmsg->msg_flags - ? O_CLOEXEC : 0); + for (i = 0; i < fdmax; i++) { + err = receive_fd_user(scm->fp->fp[i], cmsg_data + i, o_flags); if (err < 0) break; - new_fd = err; - err = put_user(new_fd, cmfptr); - if (err) { - put_unused_fd(new_fd); - break; - } - /* Bump the usage count and install the file. */ - fd_install(new_fd, get_file(fp[i])); } if (i > 0) { int cmlen = CMSG_COMPAT_LEN(i * sizeof(int)); + err = put_user(SOL_SOCKET, &cm->cmsg_level); if (!err) err = put_user(SCM_RIGHTS, &cm->cmsg_type); @@ -321,16 +313,19 @@ void scm_detach_fds_compat(struct msghdr *kmsg, struct scm_cookie *scm) err = put_user(cmlen, &cm->cmsg_len); if (!err) { cmlen = CMSG_COMPAT_SPACE(i * sizeof(int)); - kmsg->msg_control += cmlen; - kmsg->msg_controllen -= cmlen; + if (msg->msg_controllen < cmlen) + cmlen = msg->msg_controllen; + msg->msg_control += cmlen; + msg->msg_controllen -= cmlen; } } - if (i < fdnum) - kmsg->msg_flags |= MSG_CTRUNC; + + if (i < scm->fp->count || (scm->fp->count && fdmax <= 0)) + msg->msg_flags |= MSG_CTRUNC; /* - * All of the files that fit in the message have had their - * usage counts incremented, so we just free the list. + * All of the files that fit in the message have had their usage counts + * incremented, so we just free the list. */ __scm_destroy(scm); } diff --git a/net/core/scm.c b/net/core/scm.c index 875df1c2989d..8156d4fb8a39 100644 --- a/net/core/scm.c +++ b/net/core/scm.c @@ -280,36 +280,6 @@ void put_cmsg_scm_timestamping(struct msghdr *msg, struct scm_timestamping_inter } EXPORT_SYMBOL(put_cmsg_scm_timestamping); -static int __scm_install_fd(struct file *file, int __user *ufd, int o_flags) -{ - struct socket *sock; - int new_fd; - int error; - - error = security_file_receive(file); - if (error) - return error; - - new_fd = get_unused_fd_flags(o_flags); - if (new_fd < 0) - return new_fd; - - error = put_user(new_fd, ufd); - if (error) { - put_unused_fd(new_fd); - return error; - } - - /* Bump the usage count and install the file. */ - sock = sock_from_file(file, &error); - if (sock) { - sock_update_netprioidx(&sock->sk->sk_cgrp_data); - sock_update_classid(&sock->sk->sk_cgrp_data); - } - fd_install(new_fd, get_file(file)); - return 0; -} - static int scm_max_fds(struct msghdr *msg) { if (msg->msg_controllen <= sizeof(struct cmsghdr)) @@ -319,29 +289,29 @@ static int scm_max_fds(struct msghdr *msg) void scm_detach_fds(struct msghdr *msg, struct scm_cookie *scm) { - struct cmsghdr __user *cm - = (__force struct cmsghdr __user*)msg->msg_control; - int o_flags = (msg->msg_flags & MSG_CMSG_CLOEXEC) ? O_CLOEXEC : 0; + struct cmsghdr __user *cm = + (__force struct cmsghdr __user *)msg->msg_control; + unsigned int o_flags = (msg->msg_flags & MSG_CMSG_CLOEXEC) ? O_CLOEXEC : 0; int fdmax = min_t(int, scm_max_fds(msg), scm->fp->count); int __user *cmsg_data = CMSG_USER_DATA(cm); int err = 0, i; + /* no use for FD passing from kernel space callers */ + if (WARN_ON_ONCE(!msg->msg_control_is_user)) + return; + if (msg->msg_flags & MSG_CMSG_COMPAT) { scm_detach_fds_compat(msg, scm); return; } - /* no use for FD passing from kernel space callers */ - if (WARN_ON_ONCE(!msg->msg_control_is_user)) - return; - for (i = 0; i < fdmax; i++) { - err = __scm_install_fd(scm->fp->fp[i], cmsg_data + i, o_flags); - if (err) + err = receive_fd_user(scm->fp->fp[i], cmsg_data + i, o_flags); + if (err < 0) break; } - if (i > 0) { + if (i > 0) { int cmlen = CMSG_LEN(i * sizeof(int)); err = put_user(SOL_SOCKET, &cm->cmsg_level); diff --git a/net/core/sock.c b/net/core/sock.c index b8ac834f5386..8ccdcdaaa673 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2842,6 +2842,27 @@ int sock_no_mmap(struct file *file, struct socket *sock, struct vm_area_struct * } EXPORT_SYMBOL(sock_no_mmap); +/* + * When a file is received (via SCM_RIGHTS, etc), we must bump the + * various sock-based usage counts. + */ +void __receive_sock(struct file *file) +{ + struct socket *sock; + int error; + + /* + * The resulting value of "error" is ignored here since we only + * need to take action when the file is a socket and testing + * "sock" for NULL is sufficient. + */ + sock = sock_from_file(file, &error); + if (sock) { + sock_update_netprioidx(&sock->sk->sk_cgrp_data); + sock_update_classid(&sock->sk->sk_cgrp_data); + } +} + ssize_t sock_no_sendpage(struct socket *sock, struct page *page, int offset, size_t size, int flags) { ssize_t res; diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h index c9f03ef93338..7f32a7099a81 100644 --- a/tools/testing/selftests/kselftest_harness.h +++ b/tools/testing/selftests/kselftest_harness.h @@ -195,8 +195,9 @@ * * .. code-block:: c * - * FIXTURE_DATA(datatype name) + * FIXTURE_DATA(datatype_name) * + * Almost always, you want just FIXTURE() instead (see below). * This call may be used when the type of the fixture data * is needed. In general, this should not be needed unless * the *self* is being passed to a helper directly. @@ -211,7 +212,7 @@ * * .. code-block:: c * - * FIXTURE(datatype name) { + * FIXTURE(fixture_name) { * type property1; * ... * }; @@ -238,7 +239,7 @@ * * .. code-block:: c * - * FIXTURE_SETUP(fixture name) { implementation } + * FIXTURE_SETUP(fixture_name) { implementation } * * Populates the required "setup" function for a fixture. An instance of the * datatype defined with FIXTURE_DATA() will be exposed as *self* for the @@ -264,7 +265,7 @@ * * .. code-block:: c * - * FIXTURE_TEARDOWN(fixture name) { implementation } + * FIXTURE_TEARDOWN(fixture_name) { implementation } * * Populates the required "teardown" function for a fixture. An instance of the * datatype defined with FIXTURE_DATA() will be exposed as *self* for the @@ -285,7 +286,7 @@ * * .. code-block:: c * - * FIXTURE_VARIANT(datatype name) { + * FIXTURE_VARIANT(fixture_name) { * type property1; * ... * }; @@ -305,8 +306,8 @@ * * .. code-block:: c * - * FIXTURE_ADD(datatype name) { - * .property1 = val1; + * FIXTURE_VARIANT_ADD(fixture_name, variant_name) { + * .property1 = val1, * ... * }; * diff --git a/tools/testing/selftests/seccomp/config b/tools/testing/selftests/seccomp/config index db1e11b08c8a..64c19d8eba79 100644 --- a/tools/testing/selftests/seccomp/config +++ b/tools/testing/selftests/seccomp/config @@ -1,2 +1,3 @@ CONFIG_SECCOMP=y CONFIG_SECCOMP_FILTER=y +CONFIG_USER_NS=y diff --git a/tools/testing/selftests/seccomp/seccomp_benchmark.c b/tools/testing/selftests/seccomp/seccomp_benchmark.c index 5838c8697ec3..91f5a89cadac 100644 --- a/tools/testing/selftests/seccomp/seccomp_benchmark.c +++ b/tools/testing/selftests/seccomp/seccomp_benchmark.c @@ -18,9 +18,9 @@ unsigned long long timing(clockid_t clk_id, unsigned long long samples) { - pid_t pid, ret; - unsigned long long i; struct timespec start, finish; + unsigned long long i; + pid_t pid, ret; pid = getpid(); assert(clock_gettime(clk_id, &start) == 0); @@ -31,30 +31,43 @@ unsigned long long timing(clockid_t clk_id, unsigned long long samples) assert(clock_gettime(clk_id, &finish) == 0); i = finish.tv_sec - start.tv_sec; - i *= 1000000000; + i *= 1000000000ULL; i += finish.tv_nsec - start.tv_nsec; - printf("%lu.%09lu - %lu.%09lu = %llu\n", + printf("%lu.%09lu - %lu.%09lu = %llu (%.1fs)\n", finish.tv_sec, finish.tv_nsec, start.tv_sec, start.tv_nsec, - i); + i, (double)i / 1000000000.0); return i; } unsigned long long calibrate(void) { - unsigned long long i; + struct timespec start, finish; + unsigned long long i, samples, step = 9973; + pid_t pid, ret; + int seconds = 15; - printf("Calibrating reasonable sample size...\n"); + printf("Calibrating sample size for %d seconds worth of syscalls ...\n", seconds); - for (i = 5; ; i++) { - unsigned long long samples = 1 << i; + samples = 0; + pid = getpid(); + assert(clock_gettime(CLOCK_MONOTONIC, &start) == 0); + do { + for (i = 0; i < step; i++) { + ret = syscall(__NR_getpid); + assert(pid == ret); + } + assert(clock_gettime(CLOCK_MONOTONIC, &finish) == 0); - /* Find something that takes more than 5 seconds to run. */ - if (timing(CLOCK_REALTIME, samples) / 1000000000ULL > 5) - return samples; - } + samples += step; + i = finish.tv_sec - start.tv_sec; + i *= 1000000000ULL; + i += finish.tv_nsec - start.tv_nsec; + } while (i < 1000000000ULL); + + return samples * seconds; } int main(int argc, char *argv[]) @@ -68,32 +81,55 @@ int main(int argc, char *argv[]) }; long ret; unsigned long long samples; - unsigned long long native, filtered; + unsigned long long native, filter1, filter2; + + printf("Current BPF sysctl settings:\n"); + system("sysctl net.core.bpf_jit_enable"); + system("sysctl net.core.bpf_jit_harden"); if (argc > 1) samples = strtoull(argv[1], NULL, 0); else samples = calibrate(); - printf("Benchmarking %llu samples...\n", samples); + printf("Benchmarking %llu syscalls...\n", samples); + /* Native call */ native = timing(CLOCK_PROCESS_CPUTIME_ID, samples) / samples; printf("getpid native: %llu ns\n", native); ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); assert(ret == 0); + /* One filter */ ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); assert(ret == 0); - filtered = timing(CLOCK_PROCESS_CPUTIME_ID, samples) / samples; - printf("getpid RET_ALLOW: %llu ns\n", filtered); + filter1 = timing(CLOCK_PROCESS_CPUTIME_ID, samples) / samples; + printf("getpid RET_ALLOW 1 filter: %llu ns\n", filter1); - printf("Estimated seccomp overhead per syscall: %llu ns\n", - filtered - native); + if (filter1 == native) + printf("No overhead measured!? Try running again with more samples.\n"); - if (filtered == native) - printf("Trying running again with more samples.\n"); + /* Two filters */ + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog); + assert(ret == 0); + + filter2 = timing(CLOCK_PROCESS_CPUTIME_ID, samples) / samples; + printf("getpid RET_ALLOW 2 filters: %llu ns\n", filter2); + + /* Calculations */ + printf("Estimated total seccomp overhead for 1 filter: %llu ns\n", + filter1 - native); + + printf("Estimated total seccomp overhead for 2 filters: %llu ns\n", + filter2 - native); + + printf("Estimated seccomp per-filter overhead: %llu ns\n", + filter2 - filter1); + + printf("Estimated seccomp entry overhead: %llu ns\n", + filter1 - native - (filter2 - filter1)); return 0; } diff --git a/tools/testing/selftests/seccomp/seccomp_bpf.c b/tools/testing/selftests/seccomp/seccomp_bpf.c index 252140a52553..5267b9fb7c0f 100644 --- a/tools/testing/selftests/seccomp/seccomp_bpf.c +++ b/tools/testing/selftests/seccomp/seccomp_bpf.c @@ -45,12 +45,19 @@ #include #include #include +#include #include #include #include #include "../kselftest_harness.h" +#include "../clone3/clone3_selftests.h" + +/* Attempt to de-conflict with the selftests tree. */ +#ifndef SKIP +#define SKIP(s, ...) XFAIL(s, ##__VA_ARGS__) +#endif #ifndef PR_SET_PTRACER # define PR_SET_PTRACER 0x59616d61 @@ -167,7 +174,9 @@ struct seccomp_metadata { #ifndef SECCOMP_FILTER_FLAG_NEW_LISTENER #define SECCOMP_FILTER_FLAG_NEW_LISTENER (1UL << 3) +#endif +#ifndef SECCOMP_RET_USER_NOTIF #define SECCOMP_RET_USER_NOTIF 0x7fc00000U #define SECCOMP_IOC_MAGIC '!' @@ -180,7 +189,7 @@ struct seccomp_metadata { #define SECCOMP_IOCTL_NOTIF_RECV SECCOMP_IOWR(0, struct seccomp_notif) #define SECCOMP_IOCTL_NOTIF_SEND SECCOMP_IOWR(1, \ struct seccomp_notif_resp) -#define SECCOMP_IOCTL_NOTIF_ID_VALID SECCOMP_IOR(2, __u64) +#define SECCOMP_IOCTL_NOTIF_ID_VALID SECCOMP_IOW(2, __u64) struct seccomp_notif { __u64 id; @@ -203,6 +212,39 @@ struct seccomp_notif_sizes { }; #endif +#ifndef SECCOMP_IOCTL_NOTIF_ADDFD +/* On success, the return value is the remote process's added fd number */ +#define SECCOMP_IOCTL_NOTIF_ADDFD SECCOMP_IOW(3, \ + struct seccomp_notif_addfd) + +/* valid flags for seccomp_notif_addfd */ +#define SECCOMP_ADDFD_FLAG_SETFD (1UL << 0) /* Specify remote fd */ + +struct seccomp_notif_addfd { + __u64 id; + __u32 flags; + __u32 srcfd; + __u32 newfd; + __u32 newfd_flags; +}; +#endif + +struct seccomp_notif_addfd_small { + __u64 id; + char weird[4]; +}; +#define SECCOMP_IOCTL_NOTIF_ADDFD_SMALL \ + SECCOMP_IOW(3, struct seccomp_notif_addfd_small) + +struct seccomp_notif_addfd_big { + union { + struct seccomp_notif_addfd addfd; + char buf[sizeof(struct seccomp_notif_addfd) + 8]; + }; +}; +#define SECCOMP_IOCTL_NOTIF_ADDFD_BIG \ + SECCOMP_IOWR(3, struct seccomp_notif_addfd_big) + #ifndef PTRACE_EVENTMSG_SYSCALL_ENTRY #define PTRACE_EVENTMSG_SYSCALL_ENTRY 1 #define PTRACE_EVENTMSG_SYSCALL_EXIT 2 @@ -236,6 +278,40 @@ int seccomp(unsigned int op, unsigned int flags, void *args) #define SIBLING_EXIT_FAILURE 0xbadface #define SIBLING_EXIT_NEWPRIVS 0xbadfeed +static int __filecmp(pid_t pid1, pid_t pid2, int fd1, int fd2) +{ +#ifdef __NR_kcmp + errno = 0; + return syscall(__NR_kcmp, pid1, pid2, KCMP_FILE, fd1, fd2); +#else + errno = ENOSYS; + return -1; +#endif +} + +/* Have TH_LOG report actual location filecmp() is used. */ +#define filecmp(pid1, pid2, fd1, fd2) ({ \ + int _ret; \ + \ + _ret = __filecmp(pid1, pid2, fd1, fd2); \ + if (_ret != 0) { \ + if (_ret < 0 && errno == ENOSYS) { \ + TH_LOG("kcmp() syscall missing (test is less accurate)");\ + _ret = 0; \ + } \ + } \ + _ret; }) + +TEST(kcmp) +{ + int ret; + + ret = __filecmp(getpid(), getpid(), 1, 1); + EXPECT_EQ(ret, 0); + if (ret != 0 && errno == ENOSYS) + SKIP(return, "Kernel does not support kcmp() (missing CONFIG_CHECKPOINT_RESTORE?)"); +} + TEST(mode_strict_support) { long ret; @@ -1470,6 +1546,7 @@ pid_t setup_trace_fixture(struct __test_metadata *_metadata, return tracer_pid; } + void teardown_trace_fixture(struct __test_metadata *_metadata, pid_t tracer) { @@ -1750,7 +1827,7 @@ void change_syscall(struct __test_metadata *_metadata, EXPECT_EQ(0, ret); } -void tracer_syscall(struct __test_metadata *_metadata, pid_t tracee, +void tracer_seccomp(struct __test_metadata *_metadata, pid_t tracee, int status, void *args) { int ret; @@ -1827,6 +1904,24 @@ FIXTURE(TRACE_syscall) { pid_t tracer, mytid, mypid, parent; }; +FIXTURE_VARIANT(TRACE_syscall) { + /* + * All of the SECCOMP_RET_TRACE behaviors can be tested with either + * SECCOMP_RET_TRACE+PTRACE_CONT or plain ptrace()+PTRACE_SYSCALL. + * This indicates if we should use SECCOMP_RET_TRACE (false), or + * ptrace (true). + */ + bool use_ptrace; +}; + +FIXTURE_VARIANT_ADD(TRACE_syscall, ptrace) { + .use_ptrace = true, +}; + +FIXTURE_VARIANT_ADD(TRACE_syscall, seccomp) { + .use_ptrace = false, +}; + FIXTURE_SETUP(TRACE_syscall) { struct sock_filter filter[] = { @@ -1842,12 +1937,11 @@ FIXTURE_SETUP(TRACE_syscall) BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_TRACE | 0x1005), BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), }; - - memset(&self->prog, 0, sizeof(self->prog)); - self->prog.filter = malloc(sizeof(filter)); - ASSERT_NE(NULL, self->prog.filter); - memcpy(self->prog.filter, filter, sizeof(filter)); - self->prog.len = (unsigned short)ARRAY_SIZE(filter); + struct sock_fprog prog = { + .len = (unsigned short)ARRAY_SIZE(filter), + .filter = filter, + }; + long ret; /* Prepare some testable syscall results. */ self->mytid = syscall(__NR_gettid); @@ -1865,60 +1959,48 @@ FIXTURE_SETUP(TRACE_syscall) ASSERT_NE(self->parent, self->mypid); /* Launch tracer. */ - self->tracer = setup_trace_fixture(_metadata, tracer_syscall, NULL, - false); + self->tracer = setup_trace_fixture(_metadata, + variant->use_ptrace ? tracer_ptrace + : tracer_seccomp, + NULL, variant->use_ptrace); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret); + + if (variant->use_ptrace) + return; + + ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); + ASSERT_EQ(0, ret); } FIXTURE_TEARDOWN(TRACE_syscall) { teardown_trace_fixture(_metadata, self->tracer); - if (self->prog.filter) - free(self->prog.filter); } -TEST_F(TRACE_syscall, ptrace_syscall_redirected) +TEST(negative_ENOSYS) { - /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */ - teardown_trace_fixture(_metadata, self->tracer); - self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL, - true); - - /* Tracer will redirect getpid to getppid. */ - EXPECT_NE(self->mypid, syscall(__NR_getpid)); + /* + * There should be no difference between an "internal" skip + * and userspace asking for syscall "-1". + */ + errno = 0; + EXPECT_EQ(-1, syscall(-1)); + EXPECT_EQ(errno, ENOSYS); + /* And no difference for "still not valid but not -1". */ + errno = 0; + EXPECT_EQ(-1, syscall(-101)); + EXPECT_EQ(errno, ENOSYS); } -TEST_F(TRACE_syscall, ptrace_syscall_errno) +TEST_F(TRACE_syscall, negative_ENOSYS) { - /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */ - teardown_trace_fixture(_metadata, self->tracer); - self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL, - true); - - /* Tracer should skip the open syscall, resulting in ESRCH. */ - EXPECT_SYSCALL_RETURN(-ESRCH, syscall(__NR_openat)); -} - -TEST_F(TRACE_syscall, ptrace_syscall_faked) -{ - /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */ - teardown_trace_fixture(_metadata, self->tracer); - self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL, - true); - - /* Tracer should skip the gettid syscall, resulting fake pid. */ - EXPECT_SYSCALL_RETURN(45000, syscall(__NR_gettid)); + negative_ENOSYS(_metadata); } TEST_F(TRACE_syscall, syscall_allowed) { - long ret; - - ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); - ASSERT_EQ(0, ret); - - ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); - ASSERT_EQ(0, ret); - /* getppid works as expected (no changes). */ EXPECT_EQ(self->parent, syscall(__NR_getppid)); EXPECT_NE(self->mypid, syscall(__NR_getppid)); @@ -1926,14 +2008,6 @@ TEST_F(TRACE_syscall, syscall_allowed) TEST_F(TRACE_syscall, syscall_redirected) { - long ret; - - ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); - ASSERT_EQ(0, ret); - - ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); - ASSERT_EQ(0, ret); - /* getpid has been redirected to getppid as expected. */ EXPECT_EQ(self->parent, syscall(__NR_getpid)); EXPECT_NE(self->mypid, syscall(__NR_getpid)); @@ -1941,33 +2015,17 @@ TEST_F(TRACE_syscall, syscall_redirected) TEST_F(TRACE_syscall, syscall_errno) { - long ret; - - ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); - ASSERT_EQ(0, ret); - - ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); - ASSERT_EQ(0, ret); - - /* openat has been skipped and an errno return. */ + /* Tracer should skip the open syscall, resulting in ESRCH. */ EXPECT_SYSCALL_RETURN(-ESRCH, syscall(__NR_openat)); } TEST_F(TRACE_syscall, syscall_faked) { - long ret; - - ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); - ASSERT_EQ(0, ret); - - ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); - ASSERT_EQ(0, ret); - - /* gettid has been skipped and an altered return value stored. */ + /* Tracer skips the gettid syscall and store altered return value. */ EXPECT_SYSCALL_RETURN(45000, syscall(__NR_gettid)); } -TEST_F(TRACE_syscall, skip_after_RET_TRACE) +TEST_F(TRACE_syscall, skip_after) { struct sock_filter filter[] = { BPF_STMT(BPF_LD|BPF_W|BPF_ABS, @@ -1982,14 +2040,7 @@ TEST_F(TRACE_syscall, skip_after_RET_TRACE) }; long ret; - ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); - ASSERT_EQ(0, ret); - - /* Install fixture filter. */ - ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); - ASSERT_EQ(0, ret); - - /* Install "errno on getppid" filter. */ + /* Install additional "errno on getppid" filter. */ ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); ASSERT_EQ(0, ret); @@ -1999,7 +2050,7 @@ TEST_F(TRACE_syscall, skip_after_RET_TRACE) EXPECT_EQ(EPERM, errno); } -TEST_F_SIGNAL(TRACE_syscall, kill_after_RET_TRACE, SIGSYS) +TEST_F_SIGNAL(TRACE_syscall, kill_after, SIGSYS) { struct sock_filter filter[] = { BPF_STMT(BPF_LD|BPF_W|BPF_ABS, @@ -2014,77 +2065,7 @@ TEST_F_SIGNAL(TRACE_syscall, kill_after_RET_TRACE, SIGSYS) }; long ret; - ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); - ASSERT_EQ(0, ret); - - /* Install fixture filter. */ - ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &self->prog, 0, 0); - ASSERT_EQ(0, ret); - - /* Install "death on getppid" filter. */ - ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); - ASSERT_EQ(0, ret); - - /* Tracer will redirect getpid to getppid, and we should die. */ - EXPECT_NE(self->mypid, syscall(__NR_getpid)); -} - -TEST_F(TRACE_syscall, skip_after_ptrace) -{ - struct sock_filter filter[] = { - BPF_STMT(BPF_LD|BPF_W|BPF_ABS, - offsetof(struct seccomp_data, nr)), - BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), - BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ERRNO | EPERM), - BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), - }; - struct sock_fprog prog = { - .len = (unsigned short)ARRAY_SIZE(filter), - .filter = filter, - }; - long ret; - - /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */ - teardown_trace_fixture(_metadata, self->tracer); - self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL, - true); - - ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); - ASSERT_EQ(0, ret); - - /* Install "errno on getppid" filter. */ - ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); - ASSERT_EQ(0, ret); - - /* Tracer will redirect getpid to getppid, and we should see EPERM. */ - EXPECT_EQ(-1, syscall(__NR_getpid)); - EXPECT_EQ(EPERM, errno); -} - -TEST_F_SIGNAL(TRACE_syscall, kill_after_ptrace, SIGSYS) -{ - struct sock_filter filter[] = { - BPF_STMT(BPF_LD|BPF_W|BPF_ABS, - offsetof(struct seccomp_data, nr)), - BPF_JUMP(BPF_JMP|BPF_JEQ|BPF_K, __NR_getppid, 0, 1), - BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_KILL), - BPF_STMT(BPF_RET|BPF_K, SECCOMP_RET_ALLOW), - }; - struct sock_fprog prog = { - .len = (unsigned short)ARRAY_SIZE(filter), - .filter = filter, - }; - long ret; - - /* Swap SECCOMP_RET_TRACE tracer for PTRACE_SYSCALL tracer. */ - teardown_trace_fixture(_metadata, self->tracer); - self->tracer = setup_trace_fixture(_metadata, tracer_ptrace, NULL, - true); - - ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); - ASSERT_EQ(0, ret); - - /* Install "death on getppid" filter. */ + /* Install additional "death on getppid" filter. */ ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog, 0, 0); ASSERT_EQ(0, ret); @@ -3069,7 +3050,7 @@ TEST(get_metadata) /* Only real root can get metadata. */ if (geteuid()) { - XFAIL(return, "get_metadata requires real root"); + SKIP(return, "get_metadata requires real root"); return; } @@ -3112,7 +3093,7 @@ TEST(get_metadata) ret = ptrace(PTRACE_SECCOMP_GET_METADATA, pid, sizeof(md), &md); EXPECT_EQ(sizeof(md), ret) { if (errno == EINVAL) - XFAIL(goto skip, "Kernel does not support PTRACE_SECCOMP_GET_METADATA (missing CONFIG_CHECKPOINT_RESTORE?)"); + SKIP(goto skip, "Kernel does not support PTRACE_SECCOMP_GET_METADATA (missing CONFIG_CHECKPOINT_RESTORE?)"); } EXPECT_EQ(md.flags, SECCOMP_FILTER_FLAG_LOG); @@ -3128,7 +3109,7 @@ skip: ASSERT_EQ(0, kill(pid, SIGKILL)); } -static int user_trap_syscall(int nr, unsigned int flags) +static int user_notif_syscall(int nr, unsigned int flags) { struct sock_filter filter[] = { BPF_STMT(BPF_LD+BPF_W+BPF_ABS, @@ -3174,7 +3155,7 @@ TEST(user_notification_basic) /* Check that we get -ENOSYS with no listener attached */ if (pid == 0) { - if (user_trap_syscall(__NR_getppid, 0) < 0) + if (user_notif_syscall(__NR_getppid, 0) < 0) exit(1); ret = syscall(__NR_getppid); exit(ret >= 0 || errno != ENOSYS); @@ -3191,13 +3172,13 @@ TEST(user_notification_basic) EXPECT_EQ(seccomp(SECCOMP_SET_MODE_FILTER, 0, &prog), 0); /* Check that the basic notification machinery works */ - listener = user_trap_syscall(__NR_getppid, - SECCOMP_FILTER_FLAG_NEW_LISTENER); + listener = user_notif_syscall(__NR_getppid, + SECCOMP_FILTER_FLAG_NEW_LISTENER); ASSERT_GE(listener, 0); /* Installing a second listener in the chain should EBUSY */ - EXPECT_EQ(user_trap_syscall(__NR_getppid, - SECCOMP_FILTER_FLAG_NEW_LISTENER), + EXPECT_EQ(user_notif_syscall(__NR_getppid, + SECCOMP_FILTER_FLAG_NEW_LISTENER), -1); EXPECT_EQ(errno, EBUSY); @@ -3258,15 +3239,20 @@ TEST(user_notification_with_tsync) int ret; unsigned int flags; + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + /* these were exclusive */ flags = SECCOMP_FILTER_FLAG_NEW_LISTENER | SECCOMP_FILTER_FLAG_TSYNC; - ASSERT_EQ(-1, user_trap_syscall(__NR_getppid, flags)); + ASSERT_EQ(-1, user_notif_syscall(__NR_getppid, flags)); ASSERT_EQ(EINVAL, errno); /* but now they're not */ flags |= SECCOMP_FILTER_FLAG_TSYNC_ESRCH; - ret = user_trap_syscall(__NR_getppid, flags); + ret = user_notif_syscall(__NR_getppid, flags); close(ret); ASSERT_LE(0, ret); } @@ -3284,8 +3270,8 @@ TEST(user_notification_kill_in_middle) TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); } - listener = user_trap_syscall(__NR_getppid, - SECCOMP_FILTER_FLAG_NEW_LISTENER); + listener = user_notif_syscall(__NR_getppid, + SECCOMP_FILTER_FLAG_NEW_LISTENER); ASSERT_GE(listener, 0); /* @@ -3338,8 +3324,8 @@ TEST(user_notification_signal) ASSERT_EQ(socketpair(PF_LOCAL, SOCK_SEQPACKET, 0, sk_pair), 0); - listener = user_trap_syscall(__NR_gettid, - SECCOMP_FILTER_FLAG_NEW_LISTENER); + listener = user_notif_syscall(__NR_gettid, + SECCOMP_FILTER_FLAG_NEW_LISTENER); ASSERT_GE(listener, 0); pid = fork(); @@ -3408,8 +3394,8 @@ TEST(user_notification_closed_listener) TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); } - listener = user_trap_syscall(__NR_getppid, - SECCOMP_FILTER_FLAG_NEW_LISTENER); + listener = user_notif_syscall(__NR_getppid, + SECCOMP_FILTER_FLAG_NEW_LISTENER); ASSERT_GE(listener, 0); /* @@ -3440,10 +3426,13 @@ TEST(user_notification_child_pid_ns) struct seccomp_notif req = {}; struct seccomp_notif_resp resp = {}; - ASSERT_EQ(unshare(CLONE_NEWUSER | CLONE_NEWPID), 0); + ASSERT_EQ(unshare(CLONE_NEWUSER | CLONE_NEWPID), 0) { + if (errno == EINVAL) + SKIP(return, "kernel missing CLONE_NEWUSER support"); + }; - listener = user_trap_syscall(__NR_getppid, - SECCOMP_FILTER_FLAG_NEW_LISTENER); + listener = user_notif_syscall(__NR_getppid, + SECCOMP_FILTER_FLAG_NEW_LISTENER); ASSERT_GE(listener, 0); pid = fork(); @@ -3482,8 +3471,8 @@ TEST(user_notification_sibling_pid_ns) TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); } - listener = user_trap_syscall(__NR_getppid, - SECCOMP_FILTER_FLAG_NEW_LISTENER); + listener = user_notif_syscall(__NR_getppid, + SECCOMP_FILTER_FLAG_NEW_LISTENER); ASSERT_GE(listener, 0); pid = fork(); @@ -3505,7 +3494,10 @@ TEST(user_notification_sibling_pid_ns) } /* Create the sibling ns, and sibling in it. */ - ASSERT_EQ(unshare(CLONE_NEWPID), 0); + ASSERT_EQ(unshare(CLONE_NEWPID), 0) { + if (errno == EPERM) + SKIP(return, "CLONE_NEWPID requires CAP_SYS_ADMIN"); + } ASSERT_EQ(errno, 0); pid2 = fork(); @@ -3547,8 +3539,8 @@ TEST(user_notification_fault_recv) ASSERT_EQ(unshare(CLONE_NEWUSER), 0); - listener = user_trap_syscall(__NR_getppid, - SECCOMP_FILTER_FLAG_NEW_LISTENER); + listener = user_notif_syscall(__NR_getppid, + SECCOMP_FILTER_FLAG_NEW_LISTENER); ASSERT_GE(listener, 0); pid = fork(); @@ -3585,16 +3577,6 @@ TEST(seccomp_get_notif_sizes) EXPECT_EQ(sizes.seccomp_notif_resp, sizeof(struct seccomp_notif_resp)); } -static int filecmp(pid_t pid1, pid_t pid2, int fd1, int fd2) -{ -#ifdef __NR_kcmp - return syscall(__NR_kcmp, pid1, pid2, KCMP_FILE, fd1, fd2); -#else - errno = ENOSYS; - return -1; -#endif -} - TEST(user_notification_continue) { pid_t pid; @@ -3609,7 +3591,7 @@ TEST(user_notification_continue) TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); } - listener = user_trap_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER); + listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER); ASSERT_GE(listener, 0); pid = fork(); @@ -3619,20 +3601,14 @@ TEST(user_notification_continue) int dup_fd, pipe_fds[2]; pid_t self; - ret = pipe(pipe_fds); - if (ret < 0) - exit(1); + ASSERT_GE(pipe(pipe_fds), 0); dup_fd = dup(pipe_fds[0]); - if (dup_fd < 0) - exit(1); + ASSERT_GE(dup_fd, 0); + EXPECT_NE(pipe_fds[0], dup_fd); self = getpid(); - - ret = filecmp(self, self, pipe_fds[0], dup_fd); - if (ret) - exit(2); - + ASSERT_EQ(filecmp(self, self, pipe_fds[0], dup_fd), 0); exit(0); } @@ -3673,7 +3649,7 @@ TEST(user_notification_continue) resp.val = 0; EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0) { if (errno == EINVAL) - XFAIL(goto skip, "Kernel does not support SECCOMP_USER_NOTIF_FLAG_CONTINUE"); + SKIP(goto skip, "Kernel does not support SECCOMP_USER_NOTIF_FLAG_CONTINUE"); } skip: @@ -3681,15 +3657,342 @@ skip: EXPECT_EQ(true, WIFEXITED(status)); EXPECT_EQ(0, WEXITSTATUS(status)) { if (WEXITSTATUS(status) == 2) { - XFAIL(return, "Kernel does not support kcmp() syscall"); + SKIP(return, "Kernel does not support kcmp() syscall"); return; } } } +TEST(user_notification_filter_empty) +{ + pid_t pid; + long ret; + int status; + struct pollfd pollfd; + struct clone_args args = { + .flags = CLONE_FILES, + .exit_signal = SIGCHLD, + }; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + pid = sys_clone3(&args, sizeof(args)); + ASSERT_GE(pid, 0); + + if (pid == 0) { + int listener; + + listener = user_notif_syscall(__NR_mknod, SECCOMP_FILTER_FLAG_NEW_LISTENER); + if (listener < 0) + _exit(EXIT_FAILURE); + + if (dup2(listener, 200) != 200) + _exit(EXIT_FAILURE); + + close(listener); + + _exit(EXIT_SUCCESS); + } + + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); + + /* + * The seccomp filter has become unused so we should be notified once + * the kernel gets around to cleaning up task struct. + */ + pollfd.fd = 200; + pollfd.events = POLLHUP; + + EXPECT_GT(poll(&pollfd, 1, 2000), 0); + EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0); +} + +static void *do_thread(void *data) +{ + return NULL; +} + +TEST(user_notification_filter_empty_threaded) +{ + pid_t pid; + long ret; + int status; + struct pollfd pollfd; + struct clone_args args = { + .flags = CLONE_FILES, + .exit_signal = SIGCHLD, + }; + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + pid = sys_clone3(&args, sizeof(args)); + ASSERT_GE(pid, 0); + + if (pid == 0) { + pid_t pid1, pid2; + int listener, status; + pthread_t thread; + + listener = user_notif_syscall(__NR_dup, SECCOMP_FILTER_FLAG_NEW_LISTENER); + if (listener < 0) + _exit(EXIT_FAILURE); + + if (dup2(listener, 200) != 200) + _exit(EXIT_FAILURE); + + close(listener); + + pid1 = fork(); + if (pid1 < 0) + _exit(EXIT_FAILURE); + + if (pid1 == 0) + _exit(EXIT_SUCCESS); + + pid2 = fork(); + if (pid2 < 0) + _exit(EXIT_FAILURE); + + if (pid2 == 0) + _exit(EXIT_SUCCESS); + + if (pthread_create(&thread, NULL, do_thread, NULL) || + pthread_join(thread, NULL)) + _exit(EXIT_FAILURE); + + if (pthread_create(&thread, NULL, do_thread, NULL) || + pthread_join(thread, NULL)) + _exit(EXIT_FAILURE); + + if (waitpid(pid1, &status, 0) != pid1 || !WIFEXITED(status) || + WEXITSTATUS(status)) + _exit(EXIT_FAILURE); + + if (waitpid(pid2, &status, 0) != pid2 || !WIFEXITED(status) || + WEXITSTATUS(status)) + _exit(EXIT_FAILURE); + + exit(EXIT_SUCCESS); + } + + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); + + /* + * The seccomp filter has become unused so we should be notified once + * the kernel gets around to cleaning up task struct. + */ + pollfd.fd = 200; + pollfd.events = POLLHUP; + + EXPECT_GT(poll(&pollfd, 1, 2000), 0); + EXPECT_GT((pollfd.revents & POLLHUP) ?: 0, 0); +} + +TEST(user_notification_addfd) +{ + pid_t pid; + long ret; + int status, listener, memfd, fd; + struct seccomp_notif_addfd addfd = {}; + struct seccomp_notif_addfd_small small = {}; + struct seccomp_notif_addfd_big big = {}; + struct seccomp_notif req = {}; + struct seccomp_notif_resp resp = {}; + /* 100 ms */ + struct timespec delay = { .tv_nsec = 100000000 }; + + memfd = memfd_create("test", 0); + ASSERT_GE(memfd, 0); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + /* Check that the basic notification machinery works */ + listener = user_notif_syscall(__NR_getppid, + SECCOMP_FILTER_FLAG_NEW_LISTENER); + ASSERT_GE(listener, 0); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + if (syscall(__NR_getppid) != USER_NOTIF_MAGIC) + exit(1); + exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); + } + + ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); + + addfd.srcfd = memfd; + addfd.newfd = 0; + addfd.id = req.id; + addfd.flags = 0x0; + + /* Verify bad newfd_flags cannot be set */ + addfd.newfd_flags = ~O_CLOEXEC; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); + EXPECT_EQ(errno, EINVAL); + addfd.newfd_flags = O_CLOEXEC; + + /* Verify bad flags cannot be set */ + addfd.flags = 0xff; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); + EXPECT_EQ(errno, EINVAL); + addfd.flags = 0; + + /* Verify that remote_fd cannot be set without setting flags */ + addfd.newfd = 1; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); + EXPECT_EQ(errno, EINVAL); + addfd.newfd = 0; + + /* Verify small size cannot be set */ + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_SMALL, &small), -1); + EXPECT_EQ(errno, EINVAL); + + /* Verify we can't send bits filled in unknown buffer area */ + memset(&big, 0xAA, sizeof(big)); + big.addfd = addfd; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big), -1); + EXPECT_EQ(errno, E2BIG); + + + /* Verify we can set an arbitrary remote fd */ + fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd); + /* + * The child has fds 0(stdin), 1(stdout), 2(stderr), 3(memfd), + * 4(listener), so the newly allocated fd should be 5. + */ + EXPECT_EQ(fd, 5); + EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0); + + /* Verify we can set an arbitrary remote fd with large size */ + memset(&big, 0x0, sizeof(big)); + big.addfd = addfd; + fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD_BIG, &big); + EXPECT_EQ(fd, 6); + + /* Verify we can set a specific remote fd */ + addfd.newfd = 42; + addfd.flags = SECCOMP_ADDFD_FLAG_SETFD; + fd = ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd); + EXPECT_EQ(fd, 42); + EXPECT_EQ(filecmp(getpid(), pid, memfd, fd), 0); + + /* Resume syscall */ + resp.id = req.id; + resp.error = 0; + resp.val = USER_NOTIF_MAGIC; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); + + /* + * This sets the ID of the ADD FD to the last request plus 1. The + * notification ID increments 1 per notification. + */ + addfd.id = req.id + 1; + + /* This spins until the underlying notification is generated */ + while (ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd) != -1 && + errno != -EINPROGRESS) + nanosleep(&delay, NULL); + + memset(&req, 0, sizeof(req)); + ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); + ASSERT_EQ(addfd.id, req.id); + + resp.id = req.id; + resp.error = 0; + resp.val = USER_NOTIF_MAGIC; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); + + /* Wait for child to finish. */ + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); + + close(memfd); +} + +TEST(user_notification_addfd_rlimit) +{ + pid_t pid; + long ret; + int status, listener, memfd; + struct seccomp_notif_addfd addfd = {}; + struct seccomp_notif req = {}; + struct seccomp_notif_resp resp = {}; + const struct rlimit lim = { + .rlim_cur = 0, + .rlim_max = 0, + }; + + memfd = memfd_create("test", 0); + ASSERT_GE(memfd, 0); + + ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0); + ASSERT_EQ(0, ret) { + TH_LOG("Kernel does not support PR_SET_NO_NEW_PRIVS!"); + } + + /* Check that the basic notification machinery works */ + listener = user_notif_syscall(__NR_getppid, + SECCOMP_FILTER_FLAG_NEW_LISTENER); + ASSERT_GE(listener, 0); + + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) + exit(syscall(__NR_getppid) != USER_NOTIF_MAGIC); + + + ASSERT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_RECV, &req), 0); + + ASSERT_EQ(prlimit(pid, RLIMIT_NOFILE, &lim, NULL), 0); + + addfd.srcfd = memfd; + addfd.newfd_flags = O_CLOEXEC; + addfd.newfd = 0; + addfd.id = req.id; + addfd.flags = 0; + + /* Should probably spot check /proc/sys/fs/file-nr */ + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); + EXPECT_EQ(errno, EMFILE); + + addfd.newfd = 100; + addfd.flags = SECCOMP_ADDFD_FLAG_SETFD; + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_ADDFD, &addfd), -1); + EXPECT_EQ(errno, EBADF); + + resp.id = req.id; + resp.error = 0; + resp.val = USER_NOTIF_MAGIC; + + EXPECT_EQ(ioctl(listener, SECCOMP_IOCTL_NOTIF_SEND, &resp), 0); + + /* Wait for child to finish. */ + EXPECT_EQ(waitpid(pid, &status, 0), pid); + EXPECT_EQ(true, WIFEXITED(status)); + EXPECT_EQ(0, WEXITSTATUS(status)); + + close(memfd); +} + /* * TODO: - * - add microbenchmarks * - expand NNP testing * - better arch-specific TRACE and TRAP handlers. * - endianness checking when appropriate @@ -3697,7 +4000,6 @@ skip: * - arch value testing (x86 modes especially) * - verify that FILTER_FLAG_LOG filters generate log messages * - verify that RET_LOG generates log messages - * - ... */ TEST_HARNESS_MAIN diff --git a/tools/testing/selftests/seccomp/settings b/tools/testing/selftests/seccomp/settings new file mode 100644 index 000000000000..ba4d85f74cd6 --- /dev/null +++ b/tools/testing/selftests/seccomp/settings @@ -0,0 +1 @@ +timeout=90