From: Sage Weil <sage@redhat.com>
Date: Sun, 10 Jun 2018 18:37:56 +0000 (-0500)
Subject: osd/Session: fix invalid iterator dereference in Sessoin::have_backoff()
X-Git-Tag: v13.2.1~112^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=refs%2Fpull%2F22730%2Fhead;p=ceph.git

osd/Session: fix invalid iterator dereference in Sessoin::have_backoff()

If p is i->second.end(), we do want to back up a position, but we
shouldn't dereference p for p->first.

Fixes: http://tracker.ceph.com/issues/24486
Signed-off-by: Sage Weil <sage@redhat.com>
(cherry picked from commit 2d7bfafa879ca1475173a74a84c66fd7f5e1b6bc)
---

diff --git a/src/osd/Session.h b/src/osd/Session.h
index 3ef40f4102a..76b892c9dab 100644
--- a/src/osd/Session.h
+++ b/src/osd/Session.h
@@ -177,7 +177,7 @@ struct Session : public RefCountedObject {
     }
     auto p = i->second.lower_bound(oid);
     if (p != i->second.begin() &&
-	p->first > oid) {
+	(p == i->second.end() || p->first > oid)) {
       --p;
     }
     if (p != i->second.end()) {