Willy, On 1 November 2017 at 22:25, Willy Tarreau <w@xxxxxx> wrote: > From: Andreas Gruenbacher <agruenba@xxxxxxxxxx> > > commit 899f0429c7d3eed886406cd72182bee3b96aa1f9 upstream. > > In the code added to function submit_page_section by commit b1058b981, > sdio->bio can currently be NULL when calling dio_bio_submit. This then > leads to a NULL pointer access in dio_bio_submit, so check for a NULL > bio in submit_page_section before trying to submit it instead. > > Fixes xfstest generic/250 on gfs2. > > Cc: stable@xxxxxxxxxxxxxxx > Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx> > Reviewed-by: Jan Kara <jack@xxxxxxx> > Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx> > Signed-off-by: Willy Tarreau <w@xxxxxx> > --- > fs/direct-io.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/fs/direct-io.c b/fs/direct-io.c > index e17d919..85485c1 100644 > --- a/fs/direct-io.c > +++ b/fs/direct-io.c > @@ -760,6 +760,8 @@ out: > if (sdio->boundary) { > ret = dio_send_cur_page(dio, sdio, map_bh); > dio_bio_submit(dio, sdio); > + if (sdio->bio) > + dio_bio_submit(dio, sdio); > page_cache_release(sdio->cur_page); > sdio->cur_page = NULL; > } this is incorrect; please compare with the upstream commit. Thanks, Andreas