diff options
Diffstat (limited to 'kernel/cred.c')
| -rw-r--r-- | kernel/cred.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/kernel/cred.c b/kernel/cred.c index ff8606f77d90..098af0bc0b7e 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -447,6 +447,15 @@ int commit_creds(struct cred *new) if (task->mm) set_dumpable(task->mm, suid_dumpable); task->pdeath_signal = 0; + /* + * If a task drops privileges and becomes nondumpable, + * the dumpability change must become visible before + * the credential change; otherwise, a __ptrace_may_access() + * racing with this change may be able to attach to a task it + * shouldn't be able to attach to (as if the task had dropped + * privileges without becoming nondumpable). + * Pairs with a read barrier in __ptrace_may_access(). + */ smp_wmb(); } |