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Fixes to potential buffer overflows on received data

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This commit is contained in:
Valerio De Benedetto 2024-02-08 11:31:48 +01:00
parent dde2653cb8
commit 0234a563c1
2 changed files with 3 additions and 2 deletions
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3
nanomodbus.c
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@ -648,7 +648,7 @@ nmbs_error recv_read_file_record_res(nmbs_t* nmbs, uint16_t* registers, uint16_t
return err;
uint8_t response_size = get_1(nmbs);
if (response_size > 245) {
if (response_size > 250) {
return NMBS_ERROR_INVALID_RESPONSE;
}
@ -1798,6 +1798,7 @@ nmbs_error nmbs_read_file_record(nmbs_t* nmbs, uint16_t file_number, uint16_t re
if (record_number > 0x270F)
return NMBS_ERROR_INVALID_ARGUMENT;
// In expected response: max PDU length = 253, assuming a single file request, (253 - 1 - 1 - 1 - 1) / 2 = 124
if (count > 124)
return NMBS_ERROR_INVALID_ARGUMENT;

2
tests/nanomodbus_tests.c
View File

@ -934,7 +934,7 @@ void test_fc20(nmbs_transport transport) {
expect(registers[2] == 0xAA55);
expect(registers[3] == 0xFFFF);
check(nmbs_read_file_record(&CLIENT, 255, 9999, registers, 120));
check(nmbs_read_file_record(&CLIENT, 255, 9999, registers, 124));
expect(registers[123] == 42);
stop_client_and_server();