| Submitter | Tim Gardner |
|---|---|
| Date | Sept. 5, 2012, 7:31 p.m. |
| Message ID | <1346873502-16138-1-git-send-email-tim.gardner@canonical.com> |
| Download | mbox | patch |
| Permalink | /patch/181925/ |
| State | New |
| Headers | show |
Comments
On 09/05/2012 12:31 PM, Tim Gardner wrote: > From: Oleg Nesterov <oleg@redhat.com> > > CVE-2012-2745 > > BugLink: http://bugs.launchpad.net/bugs/1023535 > > 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: <stable@vger.kernel.org> > Signed-off-by: Oleg Nesterov <oleg@redhat.com> > Acked-by: David Howells <dhowells@redhat.com> > Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> > (cherry picked from commit 79549c6dfda0603dba9a70a53467ce62d9335c33) > > Signed-off-by: Tim Gardner <tim.gardner@canonical.com> > --- > kernel/cred.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/kernel/cred.c b/kernel/cred.c > index 3a9d6dd..183543f 100644 > --- a/kernel/cred.c > +++ b/kernel/cred.c > @@ -384,6 +384,8 @@ 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 && >
Patch
diff --git a/kernel/cred.c b/kernel/cred.c index 3a9d6dd..183543f 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -384,6 +384,8 @@ 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 &&