Merge branch 'fixes-v5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull security subsystem fixes from James Morris:
 "Fixes for the security subsystem.

  The first (by Casey actually - it's misattributed) fixes a regression
  introduced with the LSM stacking changes"

* 'fixes-v5.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  LSM: Check for NULL cred-security on free
  Yama: Check for pid death before checking ancestry
  seccomp: fix UAF in user-trap code
This commit is contained in:
Linus Torvalds 2019-01-17 16:54:58 +12:00
commit 7fbfee7c80
3 changed files with 14 additions and 1 deletions

View File

@ -976,6 +976,9 @@ static int seccomp_notify_release(struct inode *inode, struct file *file)
struct seccomp_filter *filter = file->private_data;
struct seccomp_knotif *knotif;
if (!filter)
return 0;
mutex_lock(&filter->notify_lock);
/*
@ -1300,6 +1303,7 @@ out:
out_put_fd:
if (flags & SECCOMP_FILTER_FLAG_NEW_LISTENER) {
if (ret < 0) {
listener_f->private_data = NULL;
fput(listener_f);
put_unused_fd(listener);
} else {

View File

@ -1027,6 +1027,13 @@ int security_cred_alloc_blank(struct cred *cred, gfp_t gfp)
void security_cred_free(struct cred *cred)
{
/*
* There is a failure case in prepare_creds() that
* may result in a call here with ->security being NULL.
*/
if (unlikely(cred->security == NULL))
return;
call_void_hook(cred_free, cred);
}

View File

@ -368,7 +368,9 @@ static int yama_ptrace_access_check(struct task_struct *child,
break;
case YAMA_SCOPE_RELATIONAL:
rcu_read_lock();
if (!task_is_descendant(current, child) &&
if (!pid_alive(child))
rc = -EPERM;
if (!rc && !task_is_descendant(current, child) &&
!ptracer_exception_found(current, child) &&
!ns_capable(__task_cred(child)->user_ns, CAP_SYS_PTRACE))
rc = -EPERM;