Re: kern/56316: vn_open doesn't follow symlinks

[Frank Kardel <kardel%kardel.name@localhost>]

Did you notice that zfs has a wrapper zfs_vn_open for vn_open in

src/external/cddl/osnet/sys/sys/vnode.h?

static inline int
zfs_vn_open(const char *pnamep, enum uio_seg seg, int filemode, int 
createmode,
    vnode_t **vpp, enum create crwhy, mode_t umask)
{
        struct pathbuf *pb;
        int error;

        ASSERT(seg == UIO_SYSSPACE);
        ASSERT((filemode & (FWRITE | FCREAT | FTRUNC | FOFFMAX)) != 0);
        ASSERT(crwhy == CRCREAT);
        ASSERT(umask == 0);

        "

        pb = pathbuf_create(pnamep);
        error = vn_open(NULL, pb, 0, filemode, createmode, vpp, NULL, 
NULL);
        if (error == 0) {
                VOP_UNLOCK(*vpp, 0);
        }
        pathbuf_destroy(pb);
        return (error);
}

There is is forced.

Removing "filemode |= O_NOFOLLOW;" there makes ZFS opening devices via 
symlinks again.

Frank

On 07/18/21 08:55, Michael van Elst wrote:
> The following reply was made to PR kern/56316; it has been noted by GNATS.
>
> From: mlelstv%serpens.de@localhost (Michael van Elst)
> To: gnats-bugs%netbsd.org@localhost
> Cc:
> Subject: Re: kern/56316: vn_open doesn't follow symlinks
> Date: Sun, 18 Jul 2021 06:51:48 -0000 (UTC)
>
>   kardel%netbsd.org@localhost (Frank Kardel) writes:
>   
>   > We should just disable the force setting of O_NOFOLLOW in vnopen and
>   
>   It's not forced. Apparently just in the ZFS case the caller was changed
>   to set O_NOFOLLOW and there is confusion on what FOLLOW and NOFOLLOW
>   do. In fact, both are and were masked inside vn_open, so the O_NOFOLLOW
>   flag is and has been the only relevant (despite what the comment said).
>   
>