Re: git: a1d71cebc05c - main - fstatat(2): restore AT_EMPTY_PATH handling
Date: Tue, 02 May 2023 19:04:37 UTC
On Tue, May 02, 2023 at 08:00:01PM +0300, Dmitry Chagin wrote:
> On Tue, May 02, 2023 at 03:12:51PM +0000, Konstantin Belousov wrote:
> > The branch main has been updated by kib:
> >
> > URL: https://cgit.FreeBSD.org/src/commit/?id=a1d71cebc05ccfeedf95f2db3e94b17270167888
> >
> > commit a1d71cebc05ccfeedf95f2db3e94b17270167888
> > Author: Konstantin Belousov <kib@FreeBSD.org>
> > AuthorDate: 2023-05-02 15:11:39 +0000
> > Commit: Konstantin Belousov <kib@FreeBSD.org>
> > CommitDate: 2023-05-02 15:11:39 +0000
> >
> > fstatat(2): restore AT_EMPTY_PATH handling
> >
> > Fixes: cb858340dcbf214cc4c4d78dbb741620d7b3a252
> > Reported by: markj
> > Sponsored by: The FreeBSD Foundation
> > ---
> > sys/kern/vfs_syscalls.c | 6 +++++-
> > 1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/sys/kern/vfs_syscalls.c b/sys/kern/vfs_syscalls.c
> > index 5c0a291e3b0b..d68af4ea4d51 100644
> > --- a/sys/kern/vfs_syscalls.c
> > +++ b/sys/kern/vfs_syscalls.c
> > @@ -2438,8 +2438,12 @@ kern_statat(struct thread *td, int flag, int fd, const char *path,
> > AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH) | LOCKSHARED | LOCKLEAF |
> > AUDITVNODE1, pathseg, path, fd, &cap_fstat_rights);
> >
> > - if ((error = namei(&nd)) != 0)
> > + if ((error = namei(&nd)) != 0) {
> > + if (error == ENOTDIR &&
> > + (nd.ni_resflags & NIRES_EMPTYPATH) != 0)
> > + error = kern_fstat(td, fd, sbp);
> > return (error);
> > + }
>
> cache_fplookup_dirfd() doesnt set the NIRES_EMPTYPATH flag
It doesn't, but for an AT_EMPTY_PATH lookup it aborts the lookup and
returns ENOTDIR to namei(), which sets NIRES_EMPTYPATH before passing
the error up.
> > error = VOP_STAT(nd.ni_vp, sbp, td->td_ucred, NOCRED);
> > NDFREE_PNBUF(&nd);
> > vput(nd.ni_vp);
>