On Tue, May 23, 2023 at 6:24 PM David Howells <dhowells@xxxxxxxxxx> wrote:
>
> Fix cifs_limit_bvec_subset() so that it limits the span to the maximum
> specified and won't return with a size greater than max_size.
>
> Fixes: d08089f649a0 ("cifs: Change the I/O paths to use an iterator rather than a page list")
> Reported-by: Shyam Prasad N <sprasad@xxxxxxxxxxxxx>
> Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
> cc: Steve French <smfrench@xxxxxxxxx>
> cc: Rohith Surabattula <rohiths.msft@xxxxxxxxx>
> cc: Paulo Alcantara <pc@xxxxxxxxxxxxx>
> cc: Tom Talpey <tom@xxxxxxxxxx>
> cc: Jeff Layton <jlayton@xxxxxxxxxx>
> cc: linux-cifs@xxxxxxxxxxxxxxx
> cc: linux-fsdevel@xxxxxxxxxxxxxxx
> ---
> fs/cifs/file.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
> index ba7f2e09d6c8..df88b8c04d03 100644
> --- a/fs/cifs/file.c
> +++ b/fs/cifs/file.c
> @@ -3353,9 +3353,10 @@ static size_t cifs_limit_bvec_subset(const struct iov_iter *iter, size_t max_siz
> while (n && ix < nbv) {
> len = min3(n, bvecs[ix].bv_len - skip, max_size);
> span += len;
> + max_size -= len;
> nsegs++;
> ix++;
> - if (span >= max_size || nsegs >= max_segs)
> + if (max_size == 0 || nsegs >= max_segs)
> break;
> skip = 0;
> n -= len;
>
Looks good to me.
--
Regards,
Shyam
