On Wed, Mar 31, 2021 at 12:22 AM Aurélien Aptel <aaptel@xxxxxxxx> wrote:
>
> Ronnie Sahlberg <lsahlber@xxxxxxxxxx> writes:
> > +static long smb3_collapse_range(struct file *file, struct cifs_tcon *tcon,
> > + loff_t off, loff_t len)
> > +{
> > + int rc;
> > + unsigned int xid;
> > + struct cifsFileInfo *cfile = file->private_data;
> > + __le64 eof;
> > +
> > + xid = get_xid();
> > +
> > + if (off + len < off) {
> > + rc = -EFBIG;
> > + goto out;
> > + }
>
> loff_t is defined as 'long long' for me which is signed, and signed
> overflow is Undefined Behaviour, unless we compile with -fwrapv which
> I'm not sure it is something we can assume.
>
> Also, vfs_fallocate() in fs/open.c already does an overflow check before
> calling f_op->falloc(), this is probably not needed. (It's also relying
> on signed overflow so I guess it is ok...?)
Thanks.
Steve, can you drop this check from the patch?
>
> Rest of the patch looks good otherwise.
>
> Cheers,
> --
> Aurélien Aptel / SUSE Labs Samba Team
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>
