From: Jeff Layton <jlayton@kernel.org>
To: chuck.lever@oracle.com
Cc: linux-nfs@vger.kernel.org, dcritch@redhat.com, d.lesca@solinos.it
Subject: [PATCH 2/2] sunrpc: add bounds checking to svc_rqst_replace_page
Date: Fri, 17 Mar 2023 06:56:08 -0400 [thread overview]
Message-ID: <20230317105608.19393-2-jlayton@kernel.org> (raw)
In-Reply-To: <20230317105608.19393-1-jlayton@kernel.org>
There's no good way to handle this gracefully, but if rq_next_page ends
up pointing outside the array, we can at least crash the box before it
scribbles over too much else.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
net/sunrpc/svc.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index fea7ce8fba14..864e62945647 100644
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -845,6 +845,16 @@ EXPORT_SYMBOL_GPL(svc_set_num_threads);
*/
void svc_rqst_replace_page(struct svc_rqst *rqstp, struct page *page)
{
+ struct page **begin, **end;
+
+ /*
+ * Bounds check: make sure rq_next_page points into the rq_respages
+ * part of the array.
+ */
+ begin = rqstp->rq_pages;
+ end = &rqstp->rq_pages[RPCSVC_MAXPAGES];
+ BUG_ON(rqstp->rq_next_page < begin || rqstp->rq_next_page > end);
+
if (*rqstp->rq_next_page) {
if (!pagevec_space(&rqstp->rq_pvec))
__pagevec_release(&rqstp->rq_pvec);
--
2.39.2
next prev parent reply other threads:[~2023-03-17 10:56 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-17 10:56 [PATCH 1/2] nfsd: don't replace page in rq_pages if it's a continuation of last page Jeff Layton
2023-03-17 10:56 ` Jeff Layton [this message]
2023-03-17 13:44 ` [PATCH 2/2] sunrpc: add bounds checking to svc_rqst_replace_page Chuck Lever III
2023-03-17 13:52 ` Jeff Layton
2023-03-17 13:54 ` Chuck Lever III
2023-03-17 13:06 ` [PATCH 1/2] nfsd: don't replace page in rq_pages if it's a continuation of last page Jeff Layton
2023-03-17 14:16 ` Chuck Lever III
2023-03-17 14:59 ` Jeff Layton
2023-03-17 15:04 ` Chuck Lever III
2023-03-17 17:23 ` Jeff Layton
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