| From | Ben Hutchings <> | Date | Thu, 28 Dec 2017 17:05:44 +0000 | Subject | [PATCH 3.16 099/204] direct-io: Prevent NULL pointer access in submit_page_section |
| |
3.16.52-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Andreas Gruenbacher <agruenba@redhat.com>
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.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> --- fs/direct-io.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -812,7 +812,8 @@ 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; }
|