keyctl_session_to_parent(task) sets ->replacement_session_keyring, it should be processed and cleared by key_replace_session_keyring().
However, this task can fork before it notices TIF_NOTIFY_RESUME and the new child gets the bogus ->replacement_session_keyring copied by dup_task_struct(). This is obviously wrong and, if nothing else, this leads to put_cred(already_freed_cred). change copy_creds() to clear this member. If copy_process() fails before this point the wrong ->replacement_session_keyring doesn't matter, exit_creds() won't be called. Cc: <[email protected]> Signed-off-by: Oleg Nesterov <[email protected]> --- kernel/cred.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/kernel/cred.c b/kernel/cred.c index 97b36ee..e70683d 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -386,6 +386,8 @@ int copy_creds(struct task_struct *p, unsigned long clone_flags) struct cred *new; int ret; + p->replacement_session_keyring = NULL; + if ( #ifdef CONFIG_KEYS !p->cred->thread_keyring && -- 1.5.5.1 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
