On 11/13/23, Konstantin Belousov <k...@freebsd.org> wrote: > The branch main has been updated by kib: > > URL: > https://cgit.FreeBSD.org/src/commit/?id=89188bd6ba8d8332c65498f2b71c90e5ed4b9dae > > commit 89188bd6ba8d8332c65498f2b71c90e5ed4b9dae > Author: Konstantin Belousov <k...@freebsd.org> > AuthorDate: 2023-11-12 18:29:14 +0000 > Commit: Konstantin Belousov <k...@freebsd.org> > CommitDate: 2023-11-13 22:26:28 +0000 > > vn_copy_file_range(): use local variables for invp/outvp vnodes > v_mounts > > This avoids possible NULL dereference when checking mnt_vfc names. > > Reviewed by: jah, rmacklem, Olivier Certner > <olce.free...@certner.fr> > Tested by: pho > Sponsored by: The FreeBSD Foundation > MFC after: 1 week > Differential revision: https://reviews.freebsd.org/D42554 > --- > sys/kern/vfs_vnops.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c > index 4e4161ef1a7f..e2227537dde1 100644 > --- a/sys/kern/vfs_vnops.c > +++ b/sys/kern/vfs_vnops.c > @@ -3046,6 +3046,7 @@ vn_copy_file_range(struct vnode *invp, off_t *inoffp, > struct vnode *outvp, > off_t *outoffp, size_t *lenp, unsigned int flags, struct ucred > *incred, > struct ucred *outcred, struct thread *fsize_td) > { > + struct mount *inmp, *outmp; > int error; > size_t len; > uint64_t uval; > @@ -3075,15 +3076,17 @@ vn_copy_file_range(struct vnode *invp, off_t > *inoffp, struct vnode *outvp, > if (len == 0) > goto out; > > + inmp = invp->v_mount; > + outmp = outvp->v_mount; > + > /* > * If the two vnodes are for the same file system type, call > * VOP_COPY_FILE_RANGE(), otherwise call vn_generic_copy_file_range() > * which can handle copies across multiple file system types. > */ > *lenp = len; > - if (invp->v_mount == outvp->v_mount || > - strcmp(invp->v_mount->mnt_vfc->vfc_name, > - outvp->v_mount->mnt_vfc->vfc_name) == 0) > + if (inmp == outmp || strcmp(inmp->mnt_vfc->vfc_name, > + outmp->mnt_vfc->vfc_name) == 0) > error = VOP_COPY_FILE_RANGE(invp, inoffp, outvp, outoffp, > lenp, flags, incred, outcred, fsize_td); > else > >
->mnt_vfc is global per filesystem code, so this strcmp does not make any sense. mere comparison to mnt_vfc will do it. -- Mateusz Guzik <mjguzik gmail.com>
