kumquat-buildroot/package/cereal/0001-Store-a-copy-of-each-serialized-shared_ptr-within-the-archive.patch
Fabrice Fontaine 26a46564f3 package/cereal: fix CVE-2020-11105
Fix CVE-2020-11105: An issue was discovered in USC iLab cereal through
1.3.0. It employs caching of std::shared_ptr values, using the raw
pointer address as a unique identifier. This becomes problematic if an
std::shared_ptr variable goes out of scope and is freed, and a new
std::shared_ptr is allocated at the same address. Serialization fidelity
thereby becomes dependent upon memory layout. In short, serialized
std::shared_ptr variables cannot always be expected to serialize back
into their original values. This can have any number of consequences,
depending on the context within which this manifests.

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
2021-02-04 18:20:41 +01:00

68 lines
2.9 KiB
Diff

From f27c12d491955c94583512603bf32c4568f20929 Mon Sep 17 00:00:00 2001
From: Michael Walz <code@serpedon.de>
Date: Tue, 2 Feb 2021 00:50:29 +0100
Subject: [PATCH] Store a copy of each serialized shared_ptr within the archive
to prevent the shared_ptr to be freed to early. (#667)
The archives use the memory address pointed by the shared_ptr as a
unique id which must not be reused during lifetime of the archive.
Therefore, the archives stores a copy of it.
This problem was also reported as CVE-2020-11105.
[Retrieved from:
https://github.com/USCiLab/cereal/commit/f27c12d491955c94583512603bf32c4568f20929]
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
---
include/cereal/cereal.hpp | 13 +++++++++++--
include/cereal/types/memory.hpp | 2 +-
2 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/include/cereal/cereal.hpp b/include/cereal/cereal.hpp
index 99bed9d6..f0d15e8b 100644
--- a/include/cereal/cereal.hpp
+++ b/include/cereal/cereal.hpp
@@ -369,12 +369,17 @@ namespace cereal
point to the same data.
@internal
- @param addr The address (see shared_ptr get()) pointed to by the shared pointer
+ @param sharedPointer The shared pointer itself (the adress is taked via get()).
+ The archive takes a copy to prevent the memory location to be freed
+ as long as the address is used as id. This is needed to prevent CVE-2020-11105.
@return A key that uniquely identifies the pointer */
- inline std::uint32_t registerSharedPointer( void const * addr )
+ inline std::uint32_t registerSharedPointer(const std::shared_ptr<const void>& sharedPointer)
{
+ void const * addr = sharedPointer.get();
+
// Handle null pointers by just returning 0
if(addr == 0) return 0;
+ itsSharedPointerStorage.push_back(sharedPointer);
auto id = itsSharedPointerMap.find( addr );
if( id == itsSharedPointerMap.end() )
@@ -645,6 +650,10 @@ namespace cereal
//! Maps from addresses to pointer ids
std::unordered_map<void const *, std::uint32_t> itsSharedPointerMap;
+ //! Copy of shared pointers used in #itsSharedPointerMap to make sure they are kept alive
+ // during lifetime of itsSharedPointerMap to prevent CVE-2020-11105.
+ std::vector<std::shared_ptr<const void>> itsSharedPointerStorage;
+
//! The id to be given to the next pointer
std::uint32_t itsCurrentPointerId;
diff --git a/include/cereal/types/memory.hpp b/include/cereal/types/memory.hpp
index 59e9da9b..cac1f334 100644
--- a/include/cereal/types/memory.hpp
+++ b/include/cereal/types/memory.hpp
@@ -263,7 +263,7 @@ namespace cereal
{
auto & ptr = wrapper.ptr;
- uint32_t id = ar.registerSharedPointer( ptr.get() );
+ uint32_t id = ar.registerSharedPointer( ptr );
ar( CEREAL_NVP_("id", id) );
if( id & detail::msb_32bit )