reftable/record: don't abort when decoding invalid ref value type

When decoding a ref record we read its value type from the block. In
case the type itself is invalid we call `abort()`. This is rather
heavy-handed though: the data we're reading is untrusted, so we should
treat the issue as a normal and not as a programming error.

Fix this by handling the error gracefully. Note that this also requires
us to set the value type later, as otherwise we might store an invalid
type in the record.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Patrick Steinhardt
2026-07-03 14:58:47 +02:00
committed by Junio C Hamano
parent 657654b1aa
commit ed103ab7f8
2 changed files with 27 additions and 3 deletions

View File

@@ -388,7 +388,6 @@ static int reftable_ref_record_decode(void *rec, struct reftable_buf key,
r->refname[key.len] = 0;
r->update_index = update_index;
r->value_type = val_type;
switch (val_type) {
case REFTABLE_REF_VAL1:
if (in.len < hash_size) {
@@ -426,9 +425,10 @@ static int reftable_ref_record_decode(void *rec, struct reftable_buf key,
case REFTABLE_REF_DELETION:
break;
default:
abort();
break;
err = REFTABLE_FORMAT_ERROR;
goto done;
}
r->value_type = val_type;
return start.len - in.len;

View File

@@ -11,6 +11,7 @@
#include "reftable/basics.h"
#include "reftable/constants.h"
#include "reftable/record.h"
#include "reftable/reftable-error.h"
static void t_copy(struct reftable_record *rec)
{
@@ -202,6 +203,29 @@ void test_reftable_record__ref_record_roundtrip(void)
reftable_buf_release(&scratch);
}
void test_reftable_record__ref_record_decode_invalid_value_type(void)
{
struct reftable_buf scratch = REFTABLE_BUF_INIT;
struct reftable_record out = {
.type = REFTABLE_BLOCK_TYPE_REF,
};
struct reftable_buf key = REFTABLE_BUF_INIT;
uint8_t buffer[1024] = { 0 };
struct string_view dest = {
.buf = buffer,
.len = sizeof(buffer),
};
cl_must_pass(reftable_buf_addstr(&key, "refs/heads/master"));
cl_assert_equal_i(reftable_record_decode(&out, key, REFTABLE_NR_REF_VALUETYPES,
dest, REFTABLE_HASH_SIZE_SHA1, &scratch),
REFTABLE_FORMAT_ERROR);
reftable_record_release(&out);
reftable_buf_release(&key);
reftable_buf_release(&scratch);
}
void test_reftable_record__log_record_comparison(void)
{
struct reftable_record in[3] = {