From 98b350f7a15997f5866c413c16b07e2ee6348922 Mon Sep 17 00:00:00 2001 From: jeffro256 Date: Wed, 20 May 2026 11:43:09 -0500 Subject: [PATCH] contrib: fix unaligned&aliased levin buffer reads Co-authored-by: selsta --- .../net/levin_protocol_handler_async.h | 32 ++++++++++--------- 1 file changed, 17 insertions(+), 15 deletions(-) diff --git a/contrib/epee/include/net/levin_protocol_handler_async.h b/contrib/epee/include/net/levin_protocol_handler_async.h index 73d46fd8b..7b8f45c4d 100644 --- a/contrib/epee/include/net/levin_protocol_handler_async.h +++ b/contrib/epee/include/net/levin_protocol_handler_async.h @@ -576,32 +576,34 @@ public: { if(m_cache_in_buffer.size() < sizeof(bucket_head2)) { - if(m_cache_in_buffer.size() >= sizeof(uint64_t) && *((uint64_t*)m_cache_in_buffer.span(8).data()) != SWAP64LE(LEVIN_SIGNATURE)) + if(m_cache_in_buffer.size() >= sizeof(uint64_t)) { - MWARNING(m_connection_context << "Signature mismatch, connection will be closed"); - return false; + std::uint64_t levin_sig; + memcpy(&levin_sig, m_cache_in_buffer.span(sizeof(std::uint64_t)).data(), sizeof(std::uint64_t)); + if (SWAP64LE(LEVIN_SIGNATURE) != levin_sig) + { + MWARNING(m_connection_context << "Signature mismatch, connection will be closed"); + return false; + } } is_continue = false; break; } -#if BYTE_ORDER == LITTLE_ENDIAN - bucket_head2& phead = *(bucket_head2*)m_cache_in_buffer.span(sizeof(bucket_head2)).data(); -#else - bucket_head2 phead = *(bucket_head2*)m_cache_in_buffer.span(sizeof(bucket_head2)).data(); - phead.m_signature = SWAP64LE(phead.m_signature); - phead.m_cb = SWAP64LE(phead.m_cb); - phead.m_command = SWAP32LE(phead.m_command); - phead.m_return_code = SWAP32LE(phead.m_return_code); - phead.m_flags = SWAP32LE(phead.m_flags); - phead.m_protocol_version = SWAP32LE(phead.m_protocol_version); + memcpy(&m_current_head, m_cache_in_buffer.span(sizeof(bucket_head2)).data(), sizeof(bucket_head2)); +#if BYTE_ORDER != LITTLE_ENDIAN + m_current_head.m_signature = SWAP64LE(m_current_head.m_signature); + m_current_head.m_cb = SWAP64LE(m_current_head.m_cb); + m_current_head.m_command = SWAP32LE(m_current_head.m_command); + m_current_head.m_return_code = SWAP32LE(m_current_head.m_return_code); + m_current_head.m_flags = SWAP32LE(m_current_head.m_flags); + m_current_head.m_protocol_version = SWAP32LE(m_current_head.m_protocol_version); #endif - if(LEVIN_SIGNATURE != phead.m_signature) + if(LEVIN_SIGNATURE != m_current_head.m_signature) { LOG_ERROR_CC(m_connection_context, "Signature mismatch, connection will be closed"); return false; } - m_current_head = phead; m_cache_in_buffer.erase(sizeof(bucket_head2)); m_state = stream_state_body;