From: John Spray <john.spray@redhat.com>
Date: Tue, 20 Dec 2016 18:04:47 +0000 (+0000)
Subject: mds: check for errors decoding backtraces
X-Git-Tag: v11.2.1~234^2~1
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=dbedbab057bf205045c6746d3e717f1dd4e93ea2;p=ceph.git

mds: check for errors decoding backtraces

Fixes: http://tracker.ceph.com/issues/18311
Signed-off-by: John Spray <john.spray@redhat.com>
(cherry picked from commit 6f489c74ac0040631fde0ceb0926cbab24d3ad55)
---

diff --git a/src/mds/MDCache.cc b/src/mds/MDCache.cc
index 2d6e412b29f..9cff6e9c544 100644
--- a/src/mds/MDCache.cc
+++ b/src/mds/MDCache.cc
@@ -8318,7 +8318,14 @@ void MDCache::_open_ino_backtrace_fetched(inodeno_t ino, bufferlist& bl, int err
 
   inode_backtrace_t backtrace;
   if (err == 0) {
-    ::decode(backtrace, bl);
+    try {
+      ::decode(backtrace, bl);
+    } catch (const buffer::error &decode_exc) {
+      derr << "corrupt backtrace on ino x0" << std::hex << ino
+           << std::dec << ": " << decode_exc << dendl;
+      open_ino_finish(ino, info, -EIO);
+      return;
+    }
     if (backtrace.pool != info.pool && backtrace.pool != -1) {
       dout(10) << " old object in pool " << info.pool
 	       << ", retrying pool " << backtrace.pool << dendl;