Merge tag 'seccomp-v5.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull seccomp fixes from Kees Cook:
 "This fixes a rare race condition in seccomp when using TSYNC and
  USER_NOTIF together where a memory allocation would not get freed
  (found by syzkaller, fixed by Tycho).

  Additionally updates Tycho's MAINTAINERS and .mailmap entries for his
  new address"

* tag 'seccomp-v5.9-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  seccomp: don't leave dangling ->notif if file allocation fails
  mailmap, MAINTAINERS: move to tycho.pizza
  seccomp: don't leak memory when filter install races
This commit is contained in:
Linus Torvalds
2020-09-12 12:58:01 -07:00
3 changed files with 20 additions and 7 deletions

View File

@@ -1109,13 +1109,18 @@ out:
}
#ifdef CONFIG_SECCOMP_FILTER
static int seccomp_notify_release(struct inode *inode, struct file *file)
static void seccomp_notify_free(struct seccomp_filter *filter)
{
kfree(filter->notif);
filter->notif = NULL;
}
static void seccomp_notify_detach(struct seccomp_filter *filter)
{
struct seccomp_filter *filter = file->private_data;
struct seccomp_knotif *knotif;
if (!filter)
return 0;
return;
mutex_lock(&filter->notify_lock);
@@ -1139,9 +1144,15 @@ static int seccomp_notify_release(struct inode *inode, struct file *file)
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;
}
@@ -1488,7 +1499,7 @@ static struct file *init_listener(struct seccomp_filter *filter)
out_notif:
if (IS_ERR(ret))
kfree(filter->notif);
seccomp_notify_free(filter);
out:
return ret;
}
@@ -1581,6 +1592,7 @@ out_put_fd:
listener_f->private_data = NULL;
fput(listener_f);
put_unused_fd(listener);
seccomp_notify_detach(prepared);
} else {
fd_install(listener, listener_f);
ret = listener;