Test `./tests/shell/run-tests.sh -V tests/shell/testcases/maps/nat_addr_port`
fails:
==118== 195 (112 direct, 83 indirect) bytes in 1 blocks are definitely lost in loss record 3 of 3
==118== at 0x484682C: calloc (vg_replace_malloc.c:1554)
==118== by 0x48A39DD: xmalloc (utils.c:37)
==118== by 0x48A39DD: xzalloc (utils.c:76)
==118== by 0x487BDFD: datatype_alloc (datatype.c:1205)
==118== by 0x487BDFD: concat_type_alloc (datatype.c:1288)
==118== by 0x488229D: stmt_evaluate_nat_map (evaluate.c:3786)
==118== by 0x488229D: stmt_evaluate_nat (evaluate.c:3892)
==118== by 0x488229D: stmt_evaluate (evaluate.c:4450)
==118== by 0x488328E: rule_evaluate (evaluate.c:4956)
==118== by 0x48ADC71: nft_evaluate (libnftables.c:552)
==118== by 0x48AEC29: nft_run_cmd_from_buffer (libnftables.c:595)
==118== by 0x402983: main (main.c:534)
I think the reference handling for datatype is wrong. It was introduced
by commit 01a13882bb59 ('src: add reference counter for dynamic
datatypes').
We don't notice it most of the time, because instances are statically
allocated, where datatype_get()/datatype_free() is a NOP.
Fix and rework.
- Commit 01a13882bb59 comments "The reference counter of any newly
allocated datatype is set to zero". That seems not workable.
Previously, functions like datatype_clone() would have returned the
refcnt set to zero. Some callers would then then set the refcnt to one, but
some wouldn't (set_datatype_alloc()). Calling datatype_free() with a
refcnt of zero will overflow to UINT_MAX and leak:
if (--dtype->refcnt > 0)
return;
While there could be schemes with such asymetric counting, juggle the
appropriate number of datatype_get() and datatype_free() calls, this is
confusing and error prone. The common pattern is that every
alloc/clone/get/ref is paired with exactly one unref/free.
Let datatype_clone() return references with refcnt set 1 and in
general be always clear about where we transfer ownership (take a
reference) and where we need to release it.
- set_datatype_alloc() needs to consistently return ownership to the
reference. Previously, some code paths would and others wouldn't.
- Replace
datatype_set(key, set_datatype_alloc(dtype, key->byteorder))
with a datatype_set_take() (for "take" ownership).
Signed-off-by: Thomas Haller <thaller@xxxxxxxxxx>
Fixes: 01a13882bb59 ('src: add reference counter for dynamic datatypes')
---
include/datatype.h | 1 +
include/expression.h | 3 +
src/datatype.c | 24 ++++++--
src/evaluate.c | 120 ++++++++++++++++++++++++--------------
src/expression.c | 2 +-
src/netlink.c | 33 ++++++-----
src/netlink_delinearize.c | 2 +-
src/payload.c | 3 +-
8 files changed, 120 insertions(+), 68 deletions(-)
diff --git a/include/datatype.h b/include/datatype.h
index 6146eda1d2ec..dc11b8331043 100644
--- a/include/datatype.h
+++ b/include/datatype.h
@@ -176,6 +176,7 @@ extern const struct datatype *datatype_lookup(enum datatypes type);
extern const struct datatype *datatype_lookup_byname(const char *name);
extern struct datatype *datatype_get(const struct datatype *dtype);
extern void datatype_set(struct expr *expr, const struct datatype *dtype);
+extern void datatype_set_take(struct expr *expr, const struct datatype *dtype);
extern void datatype_free(const struct datatype *dtype);
struct datatype *datatype_clone(const struct datatype *orig_dtype);
diff --git a/include/expression.h b/include/expression.h
index 733dd3cfc89c..9a12c4c260b1 100644
--- a/include/expression.h
+++ b/include/expression.h
@@ -120,7 +120,10 @@ enum symbol_types {
* @maxval: expected maximum value
*/
struct expr_ctx {
+ /* expr_ctx does not own the refrence to dtype. The caller must
+ * ensure the valid lifetime. */
const struct datatype *dtype;
+
enum byteorder byteorder;
unsigned int len;
unsigned int maxval;
diff --git a/src/datatype.c b/src/datatype.c
index 1531a5d2a601..6dcf7f972e27 100644
--- a/src/datatype.c
+++ b/src/datatype.c
@@ -1205,6 +1205,7 @@ static struct datatype *datatype_alloc(void)
dtype = xzalloc(sizeof(*dtype));
dtype->flags = DTYPE_F_ALLOC;
+ dtype->refcnt = 1;
return dtype;
}
@@ -1222,12 +1223,22 @@ struct datatype *datatype_get(const struct datatype *ptr)
return dtype;
}
+void datatype_set_take(struct expr *expr, const struct datatype *dtype)
+{
+ const struct datatype *dtype_free;
+
+ dtype_free = expr->dtype;
+ expr->dtype = dtype;
+ datatype_free(dtype_free);
+}
+
void datatype_set(struct expr *expr, const struct datatype *dtype)
{
- if (dtype == expr->dtype)
- return;
- datatype_free(expr->dtype);
+ const struct datatype *dtype_free;
+
+ dtype_free = expr->dtype;
expr->dtype = datatype_get(dtype);
+ datatype_free(dtype_free);
}
struct datatype *datatype_clone(const struct datatype *orig_dtype)
@@ -1239,7 +1250,7 @@ struct datatype *datatype_clone(const struct datatype *orig_dtype)
dtype->name = xstrdup(orig_dtype->name);
dtype->desc = xstrdup(orig_dtype->desc);
dtype->flags = DTYPE_F_ALLOC | orig_dtype->flags;
- dtype->refcnt = 0;
+ dtype->refcnt = 1;
return dtype;
}
@@ -1252,6 +1263,9 @@ void datatype_free(const struct datatype *ptr)
return;
if (!(dtype->flags & DTYPE_F_ALLOC))
return;
+
+ assert(dtype->refcnt != 0);
+
if (--dtype->refcnt > 0)
return;
@@ -1304,7 +1318,7 @@ const struct datatype *set_datatype_alloc(const struct datatype *orig_dtype,
/* Restrict dynamic datatype allocation to generic integer datatype. */
if (orig_dtype != &integer_type)
- return orig_dtype;
+ return datatype_get(orig_dtype);
dtype = datatype_clone(orig_dtype);
dtype->byteorder = byteorder;
diff --git a/src/evaluate.c b/src/evaluate.c
index 922ce42114a5..8a7b076d96f5 100644
--- a/src/evaluate.c
+++ b/src/evaluate.c
@@ -83,7 +83,7 @@ static void key_fix_dtype_byteorder(struct expr *key)
if (dtype->byteorder == key->byteorder)
return;
- datatype_set(key, set_datatype_alloc(dtype, key->byteorder));
+ datatype_set_take(key, set_datatype_alloc(dtype, key->byteorder));
}
static int set_evaluate(struct eval_ctx *ctx, struct set *set);
@@ -1522,8 +1522,7 @@ static int expr_evaluate_concat(struct eval_ctx *ctx, struct expr **expr)
clone = datatype_clone(i->dtype);
clone->size = i->len;
clone->byteorder = i->byteorder;
- clone->refcnt = 1;
- i->dtype = clone;
+ datatype_set_take(i, clone);
}
if (dtype == NULL && i->dtype->size == 0)
@@ -1551,7 +1550,7 @@ static int expr_evaluate_concat(struct eval_ctx *ctx, struct expr **expr)
}
(*expr)->flags |= flags;
- datatype_set(*expr, concat_type_alloc(ntype));
+ datatype_set_take(*expr, concat_type_alloc(ntype));
(*expr)->len = size;
if (off > 0)
@@ -1887,10 +1886,11 @@ static int mapping_expr_expand(struct eval_ctx *ctx)
static int expr_evaluate_map(struct eval_ctx *ctx, struct expr **expr)
{
+ const struct datatype *dtype = NULL;
struct expr *map = *expr, *mappings;
struct expr_ctx ectx = ctx->ectx;
- const struct datatype *dtype;
struct expr *key, *data;
+ int r;
if (map->map->etype == EXPR_CT &&
(map->map->ct.key == NFT_CT_SRC ||
@@ -1948,23 +1948,31 @@ static int expr_evaluate_map(struct eval_ctx *ctx, struct expr **expr)
map->mappings = mappings;
ctx->set = mappings->set;
- if (expr_evaluate(ctx, &map->mappings->set->init) < 0)
- return -1;
+ if (expr_evaluate(ctx, &map->mappings->set->init) < 0) {
+ r = -1;
+ goto out;
+ }
if (set_is_interval(map->mappings->set->init->set_flags) &&
!(map->mappings->set->init->set_flags & NFT_SET_CONCAT) &&
- interval_set_eval(ctx, ctx->set, map->mappings->set->init) < 0)
- return -1;
+ interval_set_eval(ctx, ctx->set, map->mappings->set->init) < 0) {
+ r = -1;
+ goto out;
+ }
expr_set_context(&ctx->ectx, ctx->set->key->dtype, ctx->set->key->len);
- if (binop_transfer(ctx, expr) < 0)
- return -1;
+ if (binop_transfer(ctx, expr) < 0) {
+ r = -1;
+ goto out;
+ }
if (ctx->set->data->flags & EXPR_F_INTERVAL) {
ctx->set->data->len *= 2;
- if (mapping_expr_expand(ctx))
- return -1;
+ if (mapping_expr_expand(ctx)) {
+ r = -1;
+ goto out;
+ }
}
ctx->set->key->len = ctx->ectx.len;
@@ -1974,12 +1982,16 @@ static int expr_evaluate_map(struct eval_ctx *ctx, struct expr **expr)
map_set_concat_info(map);
break;
case EXPR_SYMBOL:
- if (expr_evaluate(ctx, &map->mappings) < 0)
- return -1;
+ if (expr_evaluate(ctx, &map->mappings) < 0) {
+ r = -1;
+ goto out;
+ }
if (map->mappings->etype != EXPR_SET_REF ||
- !set_is_datamap(map->mappings->set->flags))
- return expr_error(ctx->msgs, map->mappings,
+ !set_is_datamap(map->mappings->set->flags)) {
+ r = expr_error(ctx->msgs, map->mappings,
"Expression is not a map");
+ goto out;
+ }
break;
case EXPR_SET_REF:
/* symbol has been already evaluated to set reference */
@@ -1989,22 +2001,30 @@ static int expr_evaluate_map(struct eval_ctx *ctx, struct expr **expr)
expr_name(map->mappings));
}
- if (!datatype_equal(map->map->dtype, map->mappings->set->key->dtype))
- return expr_binary_error(ctx->msgs, map->mappings, map->map,
+ if (!datatype_equal(map->map->dtype, map->mappings->set->key->dtype)) {
+ r = expr_binary_error(ctx->msgs, map->mappings, map->map,
"datatype mismatch, map expects %s, "
"mapping expression has type %s",
map->mappings->set->key->dtype->desc,
map->map->dtype->desc);
+ goto out;
+ }
datatype_set(map, map->mappings->set->data->dtype);
map->flags |= EXPR_F_CONSTANT;
/* Data for range lookups needs to be in big endian order */
if (map->mappings->set->flags & NFT_SET_INTERVAL &&
- byteorder_conversion(ctx, &map->map, BYTEORDER_BIG_ENDIAN) < 0)
- return -1;
+ byteorder_conversion(ctx, &map->map, BYTEORDER_BIG_ENDIAN) < 0) {
+ r = -1;
+ goto out;
+ }
- return 0;
+ r = 0;
+
+out:
+ datatype_free(dtype);
+ return r;
}
static bool data_mapping_has_interval(struct expr *data)
@@ -3766,8 +3786,10 @@ static int stmt_evaluate_nat_map(struct eval_ctx *ctx, struct stmt *stmt)
{
struct proto_ctx *pctx = eval_proto_ctx(ctx);
struct expr *one, *two, *data, *tmp;
- const struct datatype *dtype;
- int addr_type, err;
+ const struct datatype *dtype = NULL;
+ const struct datatype *dtype2;
+ int addr_type;
+ int r;
if (stmt->nat.family == NFPROTO_INET)
expr_family_infer(pctx, stmt->nat.addr, &stmt->nat.family);
@@ -3787,18 +3809,23 @@ static int stmt_evaluate_nat_map(struct eval_ctx *ctx, struct stmt *stmt)
dtype = concat_type_alloc((addr_type << TYPE_BITS) | TYPE_INET_SERVICE);
expr_set_context(&ctx->ectx, dtype, dtype->size);
- if (expr_evaluate(ctx, &stmt->nat.addr))
- return -1;
+ if (expr_evaluate(ctx, &stmt->nat.addr)) {
+ r = -1;
+ goto out;
+ }
if (pctx->protocol[PROTO_BASE_TRANSPORT_HDR].desc == NULL &&
!nat_evaluate_addr_has_th_expr(stmt->nat.addr)) {
- return stmt_binary_error(ctx, stmt->nat.addr, stmt,
+ r = stmt_binary_error(ctx, stmt->nat.addr, stmt,
"transport protocol mapping is only "
"valid after transport protocol match");
+ goto out;
}
- if (stmt->nat.addr->etype != EXPR_MAP)
- return 0;
+ if (stmt->nat.addr->etype != EXPR_MAP) {
+ r = 0;
+ goto out;
+ }
data = stmt->nat.addr->mappings->set->data;
if (data->flags & EXPR_F_INTERVAL)
@@ -3806,37 +3833,43 @@ static int stmt_evaluate_nat_map(struct eval_ctx *ctx, struct stmt *stmt)
datatype_set(data, dtype);
- if (expr_ops(data)->type != EXPR_CONCAT)
- return __stmt_evaluate_arg(ctx, stmt, dtype, dtype->size,
+ if (expr_ops(data)->type != EXPR_CONCAT) {
+ r = __stmt_evaluate_arg(ctx, stmt, dtype, dtype->size,
BYTEORDER_BIG_ENDIAN,
&stmt->nat.addr);
+ goto out;
+ }
one = list_first_entry(&data->expressions, struct expr, list);
two = list_entry(one->list.next, struct expr, list);
- if (one == two || !list_is_last(&two->list, &data->expressions))
- return __stmt_evaluate_arg(ctx, stmt, dtype, dtype->size,
+ if (one == two || !list_is_last(&two->list, &data->expressions)) {
+ r = __stmt_evaluate_arg(ctx, stmt, dtype, dtype->size,
BYTEORDER_BIG_ENDIAN,
&stmt->nat.addr);
+ goto out;
+ }
- dtype = get_addr_dtype(stmt->nat.family);
+ dtype2 = get_addr_dtype(stmt->nat.family);
tmp = one;
- err = __stmt_evaluate_arg(ctx, stmt, dtype, dtype->size,
+ r = __stmt_evaluate_arg(ctx, stmt, dtype2, dtype2->size,
BYTEORDER_BIG_ENDIAN,
&tmp);
- if (err < 0)
- return err;
+ if (r < 0)
+ goto out;
if (tmp != one)
BUG("Internal error: Unexpected alteration of l3 expression");
tmp = two;
- err = nat_evaluate_transport(ctx, stmt, &tmp);
- if (err < 0)
- return err;
+ r = nat_evaluate_transport(ctx, stmt, &tmp);
+ if (r < 0)
+ goto out;
if (tmp != two)
BUG("Internal error: Unexpected alteration of l4 expression");
- return err;
+out:
+ datatype_free(dtype);
+ return r;
}
static bool nat_concat_map(struct eval_ctx *ctx, struct stmt *stmt)
@@ -4550,8 +4583,7 @@ static int set_expr_evaluate_concat(struct eval_ctx *ctx, struct expr **expr)
dtype = datatype_clone(i->dtype);
dtype->size = i->len;
dtype->byteorder = i->byteorder;
- dtype->refcnt = 1;
- i->dtype = dtype;
+ datatype_set_take(i, dtype);
}
if (i->dtype->size == 0 && i->len == 0)
@@ -4574,7 +4606,7 @@ static int set_expr_evaluate_concat(struct eval_ctx *ctx, struct expr **expr)
}
(*expr)->flags |= flags;
- datatype_set(*expr, concat_type_alloc(ntype));
+ datatype_set_take(*expr, concat_type_alloc(ntype));
(*expr)->len = size;
expr_set_context(&ctx->ectx, (*expr)->dtype, (*expr)->len);
diff --git a/src/expression.c b/src/expression.c
index 147320f08937..232f48a16f7f 100644
--- a/src/expression.c
+++ b/src/expression.c
@@ -1014,7 +1014,7 @@ static struct expr *concat_expr_parse_udata(const struct nftnl_udata *attr)
if (!dtype)
goto err_free;
- concat_expr->dtype = datatype_get(dtype);
+ datatype_set_take(concat_expr, dtype);
concat_expr->len = len;
return concat_expr;
diff --git a/src/netlink.c b/src/netlink.c
index af6fd427bd57..eb559cf33abe 100644
--- a/src/netlink.c
+++ b/src/netlink.c
@@ -799,6 +799,9 @@ enum nft_data_types dtype_map_to_kernel(const struct datatype *dtype)
static const struct datatype *dtype_map_from_kernel(enum nft_data_types type)
{
+ /* The function always returns ownership of a reference. But for
+ * &verdict_Type and datatype_lookup(), those are static instances,
+ * we can omit the datatype_get() call. */
switch (type) {
case NFT_DATA_VERDICT:
return &verdict_type;
@@ -934,12 +937,14 @@ struct set *netlink_delinearize_set(struct netlink_ctx *ctx,
const struct nftnl_udata *ud[NFTNL_UDATA_SET_MAX + 1] = {};
enum byteorder keybyteorder = BYTEORDER_INVALID;
enum byteorder databyteorder = BYTEORDER_INVALID;
- const struct datatype *keytype, *datatype = NULL;
struct expr *typeof_expr_key, *typeof_expr_data;
struct setelem_parse_ctx set_parse_ctx;
+ const struct datatype *datatype = NULL;
+ const struct datatype *keytype = NULL;
+ const struct datatype *dtype2 = NULL;
+ const struct datatype *dtype = NULL;
const char *udata, *comment = NULL;
uint32_t flags, key, objtype = 0;
- const struct datatype *dtype;
uint32_t data_interval = 0;
bool automerge = false;
struct set *set;
@@ -978,7 +983,8 @@ struct set *netlink_delinearize_set(struct netlink_ctx *ctx,
if (keytype == NULL) {
netlink_io_error(ctx, NULL, "Unknown data type in set key %u",
key);
- return NULL;
+ set = NULL;
+ goto out;
}
flags = nftnl_set_get_u32(nls, NFTNL_SET_FLAGS);
@@ -991,8 +997,8 @@ struct set *netlink_delinearize_set(struct netlink_ctx *ctx,
netlink_io_error(ctx, NULL,
"Unknown data type in set key %u",
data);
- datatype_free(keytype);
- return NULL;
+ set = NULL;
+ goto out;
}
}
@@ -1030,19 +1036,18 @@ struct set *netlink_delinearize_set(struct netlink_ctx *ctx,
if (datatype) {
uint32_t dlen;
- dtype = set_datatype_alloc(datatype, databyteorder);
+ dtype2 = set_datatype_alloc(datatype, databyteorder);
klen = nftnl_set_get_u32(nls, NFTNL_SET_DATA_LEN) * BITS_PER_BYTE;
dlen = data_interval ? klen / 2 : klen;
if (set_udata_key_valid(typeof_expr_data, dlen)) {
typeof_expr_data->len = klen;
- datatype_free(datatype_get(dtype));
set->data = typeof_expr_data;
} else {
expr_free(typeof_expr_data);
set->data = constant_expr_alloc(&netlink_location,
- dtype,
+ dtype2,
databyteorder, klen,
NULL);
@@ -1053,16 +1058,12 @@ struct set *netlink_delinearize_set(struct netlink_ctx *ctx,
if (data_interval)
set->data->flags |= EXPR_F_INTERVAL;
-
- if (dtype != datatype)
- datatype_free(datatype);
}
dtype = set_datatype_alloc(keytype, keybyteorder);
klen = nftnl_set_get_u32(nls, NFTNL_SET_KEY_LEN) * BITS_PER_BYTE;
if (set_udata_key_valid(typeof_expr_key, klen)) {
- datatype_free(datatype_get(dtype));
set->key = typeof_expr_key;
set->key_typeof_valid = true;
} else {
@@ -1072,9 +1073,6 @@ struct set *netlink_delinearize_set(struct netlink_ctx *ctx,
NULL);
}
- if (dtype != keytype)
- datatype_free(keytype);
-
set->flags = nftnl_set_get_u32(nls, NFTNL_SET_FLAGS);
set->handle.handle.id = nftnl_set_get_u64(nls, NFTNL_SET_HANDLE);
@@ -1102,6 +1100,11 @@ struct set *netlink_delinearize_set(struct netlink_ctx *ctx,
}
}
+out:
+ datatype_free(datatype);
+ datatype_free(keytype);
+ datatype_free(dtype2);
+ datatype_free(dtype);
return set;
}
diff --git a/src/netlink_delinearize.c b/src/netlink_delinearize.c
index bde783bdf4ad..f4e9dda473c9 100644
--- a/src/netlink_delinearize.c
+++ b/src/netlink_delinearize.c
@@ -2769,7 +2769,7 @@ static void expr_postprocess(struct rule_pp_ctx *ctx, struct expr **exprp)
}
ctx->flags &= ~RULE_PP_IN_CONCATENATION;
list_splice(&tmp, &expr->expressions);
- datatype_set(expr, concat_type_alloc(ntype));
+ datatype_set_take(expr, concat_type_alloc(ntype));
break;
}
case EXPR_UNARY:
diff --git a/src/payload.c b/src/payload.c
index 179ddcbdd3fe..03aa552dec77 100644
--- a/src/payload.c
+++ b/src/payload.c
@@ -254,8 +254,7 @@ static struct expr *payload_expr_parse_udata(const struct nftnl_udata *attr)
dtype = datatype_clone(&xinteger_type);
dtype->size = len;
dtype->byteorder = BYTEORDER_BIG_ENDIAN;
- dtype->refcnt = 1;
- expr->dtype = dtype;
+ datatype_set_take(expr, dtype);
}
if (ud[NFTNL_UDATA_SET_KEY_PAYLOAD_INNER_DESC]) {
--
2.41.0
