Update Linux to v5.10.109
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz
Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 1d62fa2..305f0ec 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 <linux/refcount.h>
#include <linux/audit.h>
@@ -41,6 +42,7 @@
#include <linux/tracehook.h>
#include <linux/uaccess.h>
#include <linux/anon_inodes.h>
+#include <linux/lockdep.h>
/*
* When SECCOMP_IOCTL_NOTIF_ID_VALID was first introduced, it had the
@@ -83,11 +85,44 @@
/* The return values, only valid when in SECCOMP_NOTIFY_REPLIED */
int error;
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;
};
/**
@@ -101,27 +136,35 @@
* 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
@@ -131,15 +174,17 @@
* 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. */
@@ -151,6 +196,10 @@
*/
static void populate_seccomp_data(struct seccomp_data *sd)
{
+ /*
+ * Instead of using current_pt_reg(), we're already doing the work
+ * to safely fetch "current", so just use "task" everywhere below.
+ */
struct task_struct *task = current;
struct pt_regs *regs = task_pt_regs(task);
unsigned long args[6];
@@ -275,16 +324,14 @@
* All filters in the list are evaluated and the lowest BPF return
* value always takes priority (ignoring the DATA).
*/
- preempt_disable();
for (; f; f = f->prev) {
- u32 cur_ret = BPF_PROG_RUN(f->prog, sd);
+ u32 cur_ret = bpf_prog_run_pin_on_cpu(f->prog, sd);
if (ACTION_ONLY(cur_ret) < ACTION_ONLY(ret)) {
ret = cur_ret;
*match = f;
}
}
- preempt_enable();
return ret;
}
#endif /* CONFIG_SECCOMP_FILTER */
@@ -375,6 +422,59 @@
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
*
@@ -399,14 +499,19 @@
/* 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(&caller->seccomp.filter_count));
/*
* Don't let an unprivileged task work around
@@ -469,7 +574,9 @@
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;
}
@@ -534,8 +641,12 @@
int ret;
ret = seccomp_can_sync_threads();
- if (ret)
- return ret;
+ if (ret) {
+ if (flags & SECCOMP_FILTER_FLAG_TSYNC_ESRCH)
+ return -ESRCH;
+ else
+ return ret;
+ }
}
/* Set log flag, if present. */
@@ -548,6 +659,7 @@
*/
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)
@@ -558,7 +670,7 @@
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 */
@@ -568,30 +680,7 @@
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)
@@ -688,20 +777,20 @@
*/
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();
@@ -739,13 +828,26 @@
return filter->notif->next_id++;
}
-static void seccomp_do_user_notification(int this_syscall,
- struct seccomp_filter *match,
- const struct seccomp_data *sd)
+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)
{
int err;
+ u32 flags = 0;
long ret = 0;
struct seccomp_knotif n = {};
+ struct seccomp_kaddfd *addfd, *tmp;
mutex_lock(&match->notify_lock);
err = -ENOSYS;
@@ -758,24 +860,45 @@
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);
- mutex_unlock(&match->notify_lock);
+ wake_up_poll(&match->wqh, EPOLLIN | EPOLLRDNORM);
/*
* This is where we wait for a reply from userspace.
*/
- err = wait_for_completion_interruptible(&n.ready);
- mutex_lock(&match->notify_lock);
- if (err == 0) {
- ret = n.val;
- err = n.error;
+ do {
+ mutex_unlock(&match->notify_lock);
+ err = wait_for_completion_interruptible(&n.ready);
+ mutex_lock(&match->notify_lock);
+ if (err != 0)
+ goto interrupted;
+
+ addfd = list_first_entry_or_null(&n.addfd,
+ struct seccomp_kaddfd, list);
+ /* Check if we were woken up by a addfd message */
+ if (addfd)
+ seccomp_handle_addfd(addfd);
+
+ } while (n.state != SECCOMP_NOTIFY_REPLIED);
+
+ ret = n.val;
+ err = n.error;
+ flags = n.flags;
+
+interrupted:
+ /* 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.
*
@@ -787,8 +910,14 @@
list_del(&n.list);
out:
mutex_unlock(&match->notify_lock);
- syscall_set_return_value(current, task_pt_regs(current),
+
+ /* Userspace requests to continue the syscall. */
+ if (flags & SECCOMP_USER_NOTIF_FLAG_CONTINUE)
+ return 0;
+
+ syscall_set_return_value(current, current_pt_regs(),
err, ret);
+ return -1;
}
static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd,
@@ -819,13 +948,13 @@
/* Set low-order bits as an errno, capped at MAX_ERRNO. */
if (data > MAX_ERRNO)
data = MAX_ERRNO;
- syscall_set_return_value(current, task_pt_regs(current),
+ syscall_set_return_value(current, current_pt_regs(),
-data, 0);
goto skip;
case SECCOMP_RET_TRAP:
/* Show the handler the original registers. */
- syscall_rollback(current, task_pt_regs(current));
+ syscall_rollback(current, current_pt_regs());
/* Let the filter pass back 16 bits of data. */
seccomp_send_sigsys(this_syscall, data);
goto skip;
@@ -838,7 +967,7 @@
/* ENOSYS these calls if there is no tracer attached. */
if (!ptrace_event_enabled(current, PTRACE_EVENT_SECCOMP)) {
syscall_set_return_value(current,
- task_pt_regs(current),
+ current_pt_regs(),
-ENOSYS, 0);
goto skip;
}
@@ -858,7 +987,7 @@
if (fatal_signal_pending(current))
goto skip;
/* Check if the tracer forced the syscall to be skipped. */
- this_syscall = syscall_get_nr(current, task_pt_regs(current));
+ this_syscall = syscall_get_nr(current, current_pt_regs());
if (this_syscall < 0)
goto skip;
@@ -874,8 +1003,10 @@
return 0;
case SECCOMP_RET_USER_NOTIF:
- seccomp_do_user_notification(this_syscall, match, sd);
- goto skip;
+ if (seccomp_do_user_notification(this_syscall, match, sd))
+ goto skip;
+
+ return 0;
case SECCOMP_RET_LOG:
seccomp_log(this_syscall, 0, action, true);
@@ -894,20 +1025,20 @@
default:
seccomp_log(this_syscall, SIGSYS, action, true);
/* Dump core only if this is the last remaining thread. */
- if (action == SECCOMP_RET_KILL_PROCESS ||
+ if (action != SECCOMP_RET_KILL_THREAD ||
get_nr_threads(current) == 1) {
kernel_siginfo_t info;
/* Show the original registers in the dump. */
- syscall_rollback(current, task_pt_regs(current));
+ syscall_rollback(current, current_pt_regs());
/* Trigger a manual coredump since do_exit skips it. */
seccomp_init_siginfo(&info, this_syscall, data);
do_coredump(&info);
}
- if (action == SECCOMP_RET_KILL_PROCESS)
- do_group_exit(SIGSYS);
- else
+ if (action == SECCOMP_RET_KILL_THREAD)
do_exit(SIGSYS);
+ else
+ do_group_exit(SIGSYS);
}
unreachable();
@@ -936,7 +1067,7 @@
return 0;
this_syscall = sd ? sd->nr :
- syscall_get_nr(current, task_pt_regs(current));
+ syscall_get_nr(current, current_pt_regs());
switch (mode) {
case SECCOMP_MODE_STRICT:
@@ -985,13 +1116,18 @@
}
#ifdef CONFIG_SECCOMP_FILTER
-static int seccomp_notify_release(struct inode *inode, struct file *file)
+static void seccomp_notify_free(struct seccomp_filter *filter)
{
- struct seccomp_filter *filter = file->private_data;
+ kfree(filter->notif);
+ filter->notif = NULL;
+}
+
+static void seccomp_notify_detach(struct seccomp_filter *filter)
+{
struct seccomp_knotif *knotif;
if (!filter)
- return 0;
+ return;
mutex_lock(&filter->notify_lock);
@@ -1007,16 +1143,44 @@
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);
}
- kfree(filter->notif);
- filter->notif = NULL;
+ seccomp_notify_free(filter);
mutex_unlock(&filter->notify_lock);
+}
+
+static int seccomp_notify_release(struct inode *inode, struct file *file)
+{
+ struct seccomp_filter *filter = file->private_data;
+
+ seccomp_notify_detach(filter);
__put_seccomp_filter(filter);
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)
{
@@ -1060,7 +1224,7 @@
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);
@@ -1074,15 +1238,8 @@
* 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);
@@ -1097,26 +1254,24 @@
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)))
return -EFAULT;
- if (resp.flags)
+ if (resp.flags & ~SECCOMP_USER_NOTIF_FLAG_CONTINUE)
+ return -EINVAL;
+
+ if ((resp.flags & SECCOMP_USER_NOTIF_FLAG_CONTINUE) &&
+ (resp.error || resp.val))
return -EINVAL;
ret = mutex_lock_interruptible(&filter->notify_lock);
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;
@@ -1132,6 +1287,7 @@
knotif->state = SECCOMP_NOTIFY_REPLIED;
knotif->error = resp.error;
knotif->val = resp.val;
+ knotif->flags = resp.flags;
complete(&knotif->ready);
out:
mutex_unlock(&filter->notify_lock);
@@ -1141,7 +1297,7 @@
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;
@@ -1152,17 +1308,109 @@
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;
}
@@ -1172,6 +1420,7 @@
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);
@@ -1180,6 +1429,13 @@
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;
}
@@ -1192,7 +1448,7 @@
__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;
@@ -1208,6 +1464,9 @@
mutex_unlock(&filter->notify_lock);
+ if (refcount_read(&filter->users) == 0)
+ ret |= EPOLLHUP;
+
return ret;
}
@@ -1230,7 +1489,6 @@
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);
@@ -1242,7 +1500,7 @@
out_notif:
if (IS_ERR(ret))
- kfree(filter->notif);
+ seccomp_notify_free(filter);
out:
return ret;
}
@@ -1302,10 +1560,12 @@
* In the successful case, NEW_LISTENER returns the new listener fd.
* But in the failure case, TSYNC returns the thread that died. If you
* combine these two flags, there's no way to tell whether something
- * succeeded or failed. So, let's disallow this combination.
+ * succeeded or failed. So, let's disallow this combination if the user
+ * has not explicitly requested no errors from TSYNC.
*/
if ((flags & SECCOMP_FILTER_FLAG_TSYNC) &&
- (flags & SECCOMP_FILTER_FLAG_NEW_LISTENER))
+ (flags & SECCOMP_FILTER_FLAG_NEW_LISTENER) &&
+ ((flags & SECCOMP_FILTER_FLAG_TSYNC_ESRCH) == 0))
return -EINVAL;
/* Prepare the new filter before holding any locks. */
@@ -1363,6 +1623,7 @@
listener_f->private_data = NULL;
fput(listener_f);
put_unused_fd(listener);
+ seccomp_notify_detach(prepared);
} else {
fd_install(listener, listener_f);
ret = listener;
@@ -1790,7 +2051,7 @@
}
static int seccomp_actions_logged_handler(struct ctl_table *ro_table, int write,
- void __user *buffer, size_t *lenp,
+ void *buffer, size_t *lenp,
loff_t *ppos)
{
int ret;
@@ -1836,7 +2097,7 @@
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);