| Message ID | a129be6693b882bac11ace44d659ceb1c1cc4f79.1497520148.git.lucien.xin@gmail.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Xin Long <lucien.xin@gmail.com> Date: Thu, 15 Jun 2017 17:49:08 +0800 > In sctp_for_each_transport, pos is used to save how many objs it has > dumped. Now it gets the last obj by sctp_transport_get_idx, then gets > the next obj by sctp_transport_get_next. > > The issue is that in the meanwhile if some objs in transport hashtable > are removed and the objs nums are less than pos, sctp_transport_get_idx > would return NULL and hti.walker.tbl is NULL as well. At this moment > it should stop hti, instead of continue getting the next obj. Or it > would cause a NULL pointer dereference in sctp_transport_get_next. > > This patch is to pass pos + 1 into sctp_transport_get_idx to get the > next obj directly, even if pos > objs nums, it would return NULL and > stop hti. > > Fixes: 626d16f50f39 ("sctp: export some apis or variables for sctp_diag and reuse some for proc") > Signed-off-by: Xin Long <lucien.xin@gmail.com> Applied and queued up for -stable, thanks.
diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 30aa0a5..3a8318e 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -4666,9 +4666,8 @@ int sctp_for_each_transport(int (*cb)(struct sctp_transport *, void *), if (err) return err; - sctp_transport_get_idx(net, &hti, pos); - obj = sctp_transport_get_next(net, &hti); - for (; obj && !IS_ERR(obj); obj = sctp_transport_get_next(net, &hti)) { + obj = sctp_transport_get_idx(net, &hti, pos + 1); + for (; !IS_ERR_OR_NULL(obj); obj = sctp_transport_get_next(net, &hti)) { struct sctp_transport *transport = obj; if (!sctp_transport_hold(transport))
In sctp_for_each_transport, pos is used to save how many objs it has dumped. Now it gets the last obj by sctp_transport_get_idx, then gets the next obj by sctp_transport_get_next. The issue is that in the meanwhile if some objs in transport hashtable are removed and the objs nums are less than pos, sctp_transport_get_idx would return NULL and hti.walker.tbl is NULL as well. At this moment it should stop hti, instead of continue getting the next obj. Or it would cause a NULL pointer dereference in sctp_transport_get_next. This patch is to pass pos + 1 into sctp_transport_get_idx to get the next obj directly, even if pos > objs nums, it would return NULL and stop hti. Fixes: 626d16f50f39 ("sctp: export some apis or variables for sctp_diag and reuse some for proc") Signed-off-by: Xin Long <lucien.xin@gmail.com> --- net/sctp/socket.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)