From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: [PATCH v2 17/17] idr: Warn if old iterators see large IDs Date: Wed, 29 Nov 2017 12:19:22 -0800 Message-ID: <20171129201922.24370-18-willy@infradead.org> References: <20171129201922.24370-1-willy@infradead.org> Cc: Matthew Wilcox To: willy@infradead.org, netdev@vger.kernel.org Return-path: Received: from bombadil.infradead.org ([65.50.211.133]:46894 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752573AbdK2UTh (ORCPT ); Wed, 29 Nov 2017 15:19:37 -0500 In-Reply-To: <20171129201922.24370-1-willy@infradead.org> Sender: netdev-owner@vger.kernel.org List-ID: From: Matthew Wilcox Now that the IDR can be used to store large IDs, it is possible somebody might only partially convert their old code and use the iterators which can only handle IDs up to INT_MAX. It's probably unwise to show them a truncated ID, so settle for spewing warnings to dmesg, and terminating the iteration. Signed-off-by: Matthew Wilcox --- lib/idr.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/lib/idr.c b/lib/idr.c index 772a24513d1e..1aaeb5a8c426 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -145,7 +145,11 @@ int idr_for_each(const struct idr *idr, void __rcu **slot; radix_tree_for_each_slot(slot, &idr->idr_rt, &iter, 0) { - int ret = fn(iter.index, rcu_dereference_raw(*slot), data); + int ret; + + if (WARN_ON_ONCE(iter.index > INT_MAX)) + break; + ret = fn(iter.index, rcu_dereference_raw(*slot), data); if (ret) return ret; } @@ -173,6 +177,9 @@ void *idr_get_next(struct idr *idr, int *nextid) if (!slot) return NULL; + if (WARN_ON_ONCE(iter.index > INT_MAX)) + return NULL; + *nextid = iter.index; return rcu_dereference_raw(*slot); } -- 2.15.0