The branch main has been updated by jah: URL: https://cgit.FreeBSD.org/src/commit/?id=b18029bc59d2ed6b0eeeb233189cf713b34b467c
commit b18029bc59d2ed6b0eeeb233189cf713b34b467c Author: Jason A. Harmening <[email protected]> AuthorDate: 2024-02-18 00:19:32 +0000 Commit: Jason A. Harmening <[email protected]> CommitDate: 2024-04-09 22:36:59 +0000 unionfs_lookup(): fix wild accesses to vnode private data There are a few spots in which unionfs_lookup() accesses unionfs vnode private data without holding the corresponding vnode lock or interlock. Reviewed by: kib, olce MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D44601 --- sys/fs/unionfs/union_vnops.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-) diff --git a/sys/fs/unionfs/union_vnops.c b/sys/fs/unionfs/union_vnops.c index 3e8853baeb4d..187d0513da25 100644 --- a/sys/fs/unionfs/union_vnops.c +++ b/sys/fs/unionfs/union_vnops.c @@ -79,7 +79,7 @@ static int unionfs_lookup(struct vop_cachedlookup_args *ap) { - struct unionfs_node *dunp; + struct unionfs_node *dunp, *unp; struct vnode *dvp, *udvp, *ldvp, *vp, *uvp, *lvp, *dtmpvp; struct vattr va; struct componentname *cnp; @@ -139,6 +139,9 @@ unionfs_lookup(struct vop_cachedlookup_args *ap) if (dtmpvp == udvp && ldvp != NULLVP) { VOP_UNLOCK(udvp); vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY); + dunp = VTOUNIONFS(dvp); + if (error == 0 && dunp == NULL) + error = ENOENT; } if (error == 0) { @@ -152,14 +155,15 @@ unionfs_lookup(struct vop_cachedlookup_args *ap) VOP_UNLOCK(vp); vrele(vp); + dtmpvp = dunp->un_dvp; + vref(dtmpvp); VOP_UNLOCK(dvp); - *(ap->a_vpp) = dunp->un_dvp; - vref(dunp->un_dvp); + *(ap->a_vpp) = dtmpvp; if (nameiop == DELETE || nameiop == RENAME) - vn_lock(dunp->un_dvp, LK_EXCLUSIVE | LK_RETRY); + vn_lock(dtmpvp, LK_EXCLUSIVE | LK_RETRY); else if (cnp->cn_lkflags & LK_TYPE_MASK) - vn_lock(dunp->un_dvp, cnp->cn_lkflags | + vn_lock(dtmpvp, cnp->cn_lkflags | LK_RETRY); vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY); @@ -272,8 +276,12 @@ unionfs_lookup(struct vop_cachedlookup_args *ap) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); lockflag = 1; } - error = unionfs_mkshadowdir(MOUNTTOUNIONFSMOUNT(dvp->v_mount), - udvp, VTOUNIONFS(vp), cnp, td); + unp = VTOUNIONFS(vp); + if (unp == NULL) + error = ENOENT; + else + error = unionfs_mkshadowdir(MOUNTTOUNIONFSMOUNT(dvp->v_mount), + udvp, unp, cnp, td); if (lockflag != 0) VOP_UNLOCK(vp); if (error != 0) {
