Details
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Bug
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Status: Resolved
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Major
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Resolution: Fixed
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0.7.0, 0.7.1, 0.8.0, 0.9.0, 0.9.1, 1.0.0, 1.0.1, 1.1.0, 1.2.0, 1.3.0, 1.3.1, 1.4.0, 1.5.0, 1.6.0, 1.7.0, 1.7.1
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None
Description
As it's seen from the code snippet from src/kudu/tablet/tablet_bootstrap.cc, the TabletBootstrap::HandleCommitMessage() can return non-OK status while applying pending commits via ApplyCommitMessage(), when commit_entry is already deallocated after prior call to ApplyCommitMessage():
OpId last_applied = commit_entry->commit().commited_op_id(); RETURN_NOT_OK(ApplyCommitMessage(state, commit_entry)); delete commit_entry; auto iter = state->pending_commits.begin(); while (iter != state->pending_commits.end()) { if ((*iter).first == last_applied.index() + 1) { gscoped_ptr<LogEntryPB> buffered_commit_entry((*iter).second); state->pending_commits.erase(iter++); last_applied = buffered_commit_entry->commit().commited_op_id(); RETURN_NOT_OK(ApplyCommitMessage(state, buffered_commit_entry.get())); continue; } break; } return Status::OK();
That violates the contract of the TabletBootstrap::HandleCommitMessage(), so the following code does use-after-free and can get SIGSEGV while calling DebugInfo() to get more information on the entry:
s = HandleEntry(&state, entry.get());
if (!s.ok()) {
DumpReplayStateToLog(state);
RETURN_NOT_OK_PREPEND(s, DebugInfo(tablet_->tablet_id(),
segment->header().sequence_number(),
entry_count, segment->path(),
*entry));
}
The error message just before the crash looks like the following:
Failed to play WRITE_OP request. ReplicateMsg: { ... }, CommitMsg: { ... }: Could not decode row operations: rows: <redacted>
indirect data: <redacted>:
Client provided column xxx[string NULLABLE] not present in tablet
The stack trace in the core file looks like the following:
#0 0x0000000001e343a0 in GetDescriptor (this=0x7ff9f4a5e8c0, message=..., generator=0x7ff9f4a5e7e0)
at thirdparty/src/protobuf-3.4.1/src/google/protobuf/message.h:332
#1 google::protobuf::TextFormat::Printer::Print (this=0x7ff9f4a5e8c0, message=..., generator=0x7ff9f4a5e7e0)
at thirdparty/src/protobuf-3.4.1/src/google/protobuf/text_format.cc:1836
#2 0x0000000001e3460c in google::protobuf::TextFormat::Printer::Print (this=Unhandled dwarf expression opcode 0xf3
)
at thirdparty/src/protobuf-3.4.1/src/google/protobuf/text_format.cc:1759
#3 0x0000000001e346ad in google::protobuf::TextFormat::Printer::PrintToString (this=0x7ff9f4a5e8c0, message=..., output=0x7ff9f4a5eaf0)
at thirdparty/src/protobuf-3.4.1/src/google/protobuf/text_format.cc:1742
#4 0x0000000001c83a95 in kudu::pb_util::SecureShortDebugString (msg=...)
at src/kudu/util/pb_util.cc:603
#5 0x00000000009fe50b in DebugInfo (this=Unhandled dwarf expression opcode 0xf3)
at src/kudu/tablet/tablet_bootstrap.cc:468
#6 kudu::tablet::TabletBootstrap::PlaySegments (this=Unhandled dwarf expression opcode 0xf3)
at src/kudu/tablet/tablet_bootstrap.cc:1177
#7 0x00000000009ffc4b in kudu::tablet::TabletBootstrap::RunBootstrap (this=0x7ff9f4a5f510, rebuilt_tablet=0x7ff9f4a5f8a0, rebuilt_log=0x7ff9f4a5f870, consensus_info=0x7ff9f4a5f9d0)
at src/kudu/tablet/tablet_bootstrap.cc:586
The affected 'after-free' message looks like the following in the captured core:
{<google::protobuf::MessageLite> = {_vptr.MessageLite = 0xc}, <No data fields>}
The 0xc address for vptr is invalid and the process got SIGSEGV while calling Message::GetDescriptor(), a virtual method.