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Commit 070848b9 authored by Daniel Zheng's avatar Daniel Zheng
Browse files

libsnapshot: add check for updating next_data_pos_ 

Adding a check here to ensure that next_data_pos_ isn't modified since
initialization. After sizing the sequence buffer, this value should be
the initialized value + the size of sequence buffer.

Test: cow_api_test
Change-Id: I9c79041b72544500989860a13ca6c25830d28750
parent 3f3162c2

fs_mgr/libsnapshot/libsnapshot_cow/writer_v3.cpp

+6 −0
Original line number Diff line number Diff line
@@ -399,8 +399,14 @@ bool CowWriterV3::EmitSequenceData(size_t num_ops, const uint32_t* data) { 
                      "operation writes.";

        return false;

    }



    header_.sequence_data_count = num_ops;



    // Ensure next_data_pos_ is updated as previously initialized + the newly added sequence buffer.

    CHECK_EQ(next_data_pos_ + header_.sequence_data_count * sizeof(uint32_t),

             GetDataOffset(header_));

    next_data_pos_ = GetDataOffset(header_);



    if (!android::base::WriteFullyAtOffset(fd_, data, sizeof(data[0]) * num_ops,

                                           GetSequenceOffset(header_))) {

        PLOG(ERROR) << "writing sequence buffer failed";