> On 10 Oct 2016, at 20:56, Nikolay Borisov <kernel@xxxxxxxx> wrote: > > In case __ceph_do_getattr returns an error and the retry_op in > ceph_read_iter is not READ_INLINE, then it's possible to invoke > __free_page on a page which is NULL, this naturally leads to a crash. > This can happen when, for example, a process waiting on a MDS reply > receives sigterm. > > Fix this by explicitly checking whether the page is set or not. > > Signed-off-by: Nikolay Borisov <kernel@xxxxxxxx> > Link: http://www.spinics.net/lists/ceph-users/msg31592.html > --- > > Inverted the condition, so resending with correct condition > this time. > > fs/ceph/file.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/fs/ceph/file.c b/fs/ceph/file.c > index 3c68e6aee2f0..7413313ae6c8 100644 > --- a/fs/ceph/file.c > +++ b/fs/ceph/file.c > @@ -929,7 +929,8 @@ again: > statret = __ceph_do_getattr(inode, page, > CEPH_STAT_CAP_INLINE_DATA, !!page); > if (statret < 0) { > - __free_page(page); > + if (page) > + __free_page(page); > if (statret == -ENODATA) { > BUG_ON(retry_op != READ_INLINE); > goto again; > — Reviewed-by: Yan, Zheng <zyan@xxxxxxxxxx> > 2.5.0 > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
