On 10/10/2016 04:11 PM, Yan, Zheng wrote: > >> 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> I believe this needs to also be tagged as stable. To whomever is going to merge it: can you please do that? > >> 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
