Date: Fri, 9 Apr 2021 05:08:47 GMT From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: ecc571a85858 - stable/12 - nullfs: protect against user creating inconsistent state Message-ID: <202104090508.13958lCl015890@gitrepo.freebsd.org>
next in thread | raw e-mail | index | archive | help
The branch stable/12 has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=ecc571a858586e7b62cae3794c0f6250a91a483b commit ecc571a858586e7b62cae3794c0f6250a91a483b Author: Konstantin Belousov <kib@FreeBSD.org> AuthorDate: 2021-04-01 17:42:14 +0000 Commit: Konstantin Belousov <kib@FreeBSD.org> CommitDate: 2021-04-09 04:57:37 +0000 nullfs: protect against user creating inconsistent state PR: 253593 (cherry picked from commit 76b1b5ce6d81f66b09be8a20aecd064b65fd6b50) --- sys/fs/nullfs/null_vnops.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/sys/fs/nullfs/null_vnops.c b/sys/fs/nullfs/null_vnops.c index b663d8d718d3..62351cd9d832 100644 --- a/sys/fs/nullfs/null_vnops.c +++ b/sys/fs/nullfs/null_vnops.c @@ -376,10 +376,21 @@ null_lookup(struct vop_lookup_args *ap) */ ldvp = NULLVPTOLOWERVP(dvp); vp = lvp = NULL; - KASSERT((ldvp->v_vflag & VV_ROOT) == 0 || - ((dvp->v_vflag & VV_ROOT) != 0 && (flags & ISDOTDOT) == 0), - ("ldvp %p fl %#x dvp %p fl %#x flags %#x", ldvp, ldvp->v_vflag, - dvp, dvp->v_vflag, flags)); + + /* + * Renames in the lower mounts might create an inconsistent + * configuration where lower vnode is moved out of the + * directory tree remounted by our null mount. Do not try to + * handle it fancy, just avoid VOP_LOOKUP() with DOTDOT name + * which cannot be handled by VOP, at least passing over lower + * root. + */ + if ((ldvp->v_vflag & VV_ROOT) != 0 && (flags & ISDOTDOT) != 0) { + KASSERT((dvp->v_vflag & VV_ROOT) == 0, + ("ldvp %p fl %#x dvp %p fl %#x flags %#x", + ldvp, ldvp->v_vflag, dvp, dvp->v_vflag, flags)); + return (ENOENT); + } /* * Hold ldvp. The reference on it, owned by dvp, is lost in
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202104090508.13958lCl015890>