• Peter Xu's avatar
    mm/mempolicy: Allow lookup_node() to handle fatal signal · ba841078
    Peter Xu authored
    lookup_node() uses gup to pin the page and get node information.  It
    checks against ret>=0 assuming the page will be filled in.  However it's
    also possible that gup will return zero, for example, when the thread is
    quickly killed with a fatal signal.  Teach lookup_node() to gracefully
    return an error -EFAULT if it happens.
    Meanwhile, initialize "page" to NULL to avoid potential risk of
    exploiting the pointer.
    Fixes: 4426e945
     ("mm/gup: allow VM_FAULT_RETRY for multiple times")
    Reported-by: syzbot+693dc11fcb53120b5559@syzkaller.appspotmail.com
    Signed-off-by: default avatarPeter Xu <peterx@redhat.com>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
mempolicy.c 76.2 KB