zqz/platform-external-webrtc
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Fix potential unsafe access to VCMTimestampMap::data

Browse Source 
The access to |_timestampMap| was guarded by a lock but
not the access to the data pointer stored in |_timestampMap|.
There was a potential race condition if new data was added
in VCMGenericDecoder::Decode() while the data pointer
retrieved from _timestampMap.Pop() was being used in
VCMDecodedFrameCallback::Decoded().

This CL moves the storage of data to within |_timestampMap|,
instead of being a pointer so that it's guarded by the same
lock.

Bug: webrtc:11229
Change-Id: I3f2afb568ed724db5719d508a73de402c4531dec
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/209361
Commit-Queue: Johannes Kron <kron@webrtc.org>
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33374}
This commit is contained in:
Johannes Kron
2021-03-03 14:39:44 +01:00
committed by Commit Bot
parent 752cbaba90
commit b6b782da68
5 changed files with 44 additions and 41 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
modules/video_coding/timestamp_map.h
View File

@ -13,23 +13,41 @@
#include <memory>
#include "absl/types/optional.h"
#include "api/rtp_packet_infos.h"
#include "api/units/timestamp.h"
#include "api/video/encoded_image.h"
#include "api/video/video_content_type.h"
#include "api/video/video_rotation.h"
#include "api/video/video_timing.h"
namespace webrtc {
struct VCMFrameInformation;
struct VCMFrameInformation {
int64_t renderTimeMs;
absl::optional<Timestamp> decodeStart;
void* userData;
VideoRotation rotation;
VideoContentType content_type;
EncodedImage::Timing timing;
int64_t ntp_time_ms;
RtpPacketInfos packet_infos;
// ColorSpace is not stored here, as it might be modified by decoders.
};
class VCMTimestampMap {
public:
explicit VCMTimestampMap(size_t capacity);
~VCMTimestampMap();
void Add(uint32_t timestamp, VCMFrameInformation* data);
VCMFrameInformation* Pop(uint32_t timestamp);
void Add(uint32_t timestamp, const VCMFrameInformation& data);
absl::optional<VCMFrameInformation> Pop(uint32_t timestamp);
size_t Size() const;
private:
struct TimestampDataTuple {
uint32_t timestamp;
VCMFrameInformation* data;
VCMFrameInformation data;
};
bool IsEmpty() const;