Date: Sat, 24 Nov 2018 17:02:31 +0000 (UTC) From: Mark Johnston <markj@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r340899 - head/sys/kern Message-ID: <201811241702.wAOH2Viv007776@repo.freebsd.org>
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Author: markj Date: Sat Nov 24 17:02:31 2018 New Revision: 340899 URL: https://svnweb.freebsd.org/changeset/base/340899 Log: Plug some kernel memory disclosures via kevent(2). The kernel may register for events on behalf of a userspace process, in which case it must be careful to zero the kevent struct that will be copied out to userspace. Reviewed by: kib MFC after: 3 days Security: kernel stack memory disclosure Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D18317 Modified: head/sys/kern/kern_event.c head/sys/kern/vfs_aio.c Modified: head/sys/kern/kern_event.c ============================================================================== --- head/sys/kern/kern_event.c Sat Nov 24 16:58:34 2018 (r340898) +++ head/sys/kern/kern_event.c Sat Nov 24 17:02:31 2018 (r340899) @@ -535,8 +535,9 @@ knote_fork(struct knlist *list, int pid) if (list == NULL) return; - list->kl_lock(list->kl_lockarg); + memset(&kev, 0, sizeof(kev)); + list->kl_lock(list->kl_lockarg); SLIST_FOREACH(kn, &list->kl_list, kn_selnext) { kq = kn->kn_kq; KQ_LOCK(kq); Modified: head/sys/kern/vfs_aio.c ============================================================================== --- head/sys/kern/vfs_aio.c Sat Nov 24 16:58:34 2018 (r340898) +++ head/sys/kern/vfs_aio.c Sat Nov 24 17:02:31 2018 (r340899) @@ -1589,6 +1589,7 @@ aio_aqueue(struct thread *td, struct aiocb *ujob, stru goto aqueue_fail; } kqfd = job->uaiocb.aio_sigevent.sigev_notify_kqueue; + memset(&kev, 0, sizeof(kev)); kev.ident = (uintptr_t)job->ujob; kev.filter = EVFILT_AIO; kev.flags = EV_ADD | EV_ENABLE | EV_FLAG1 | evflags; @@ -2155,6 +2156,7 @@ kern_lio_listio(struct thread *td, int mode, struct ai bcopy(sig, &lj->lioj_signal, sizeof(lj->lioj_signal)); if (lj->lioj_signal.sigev_notify == SIGEV_KEVENT) { /* Assume only new style KEVENT */ + memset(&kev, 0, sizeof(kev)); kev.filter = EVFILT_LIO; kev.flags = EV_ADD | EV_ENABLE | EV_FLAG1; kev.ident = (uintptr_t)uacb_list; /* something unique */
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