Hi Andreas,
On Wed, Nov 01, 2017 at 11:43:26PM +0100, Andreas Gruenbacher wrote:
> > 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.
Oh crap, sorry! I had to fix it by hand and I messed up fixing
the conflict! I've just dropped the first dio_bio_submit() so
that only the conditional one remains now.
Thanks for reporting it!
Willy
---
commit d75e8540fd8bedc8ee8d11941a7aed3a86735c47
Author: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
Date: Mon Oct 9 11:13:18 2017 +0200
direct-io: Prevent NULL pointer access in submit_page_section
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 # v3.10+
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>
diff --git a/fs/direct-io.c b/fs/direct-io.c
index e17d919..4007749 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -759,7 +759,8 @@ 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;
}