Shaochun Chen points out we leak dumper filter state allocations
stored in dump_control->data in case there is an error before netlink sets
cb_running (after which ->done will be called at some point).
In order to fix this, add .start functions and do the allocations
there.
->done is going to clean up, and in case error occurs before
->start invocation no cleanups need to be done anymore.
Reported-by: shaochun chen <cscnull@xxxxxxxxx>
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
---
There are other problematic spots outside of nf_tables too which
will need similar changes.
net/netfilter/nf_tables_api.c | 219 ++++++++++++++++++++++--------------------
1 file changed, 115 insertions(+), 104 deletions(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index d7b9748e338e..f5745e4c6513 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2271,6 +2271,39 @@ static int nf_tables_dump_rules(struct sk_buff *skb,
return skb->len;
}
+static int nf_tables_dump_rules_start(struct netlink_callback *cb)
+{
+ const struct nlattr * const *nla = cb->data;
+ struct nft_rule_dump_ctx *ctx = NULL;
+
+ if (nla[NFTA_RULE_TABLE] || nla[NFTA_RULE_CHAIN]) {
+ ctx = kzalloc(sizeof(*ctx), GFP_ATOMIC);
+ if (!ctx)
+ return -ENOMEM;
+
+ if (nla[NFTA_RULE_TABLE]) {
+ ctx->table = nla_strdup(nla[NFTA_RULE_TABLE],
+ GFP_ATOMIC);
+ if (!ctx->table) {
+ kfree(ctx);
+ return -ENOMEM;
+ }
+ }
+ if (nla[NFTA_RULE_CHAIN]) {
+ ctx->chain = nla_strdup(nla[NFTA_RULE_CHAIN],
+ GFP_ATOMIC);
+ if (!ctx->chain) {
+ kfree(ctx->table);
+ kfree(ctx);
+ return -ENOMEM;
+ }
+ }
+ }
+
+ cb->data = ctx;
+ return 0;
+}
+
static int nf_tables_dump_rules_done(struct netlink_callback *cb)
{
struct nft_rule_dump_ctx *ctx = cb->data;
@@ -2300,38 +2333,13 @@ static int nf_tables_getrule(struct net *net, struct sock *nlsk,
if (nlh->nlmsg_flags & NLM_F_DUMP) {
struct netlink_dump_control c = {
+ .start= nf_tables_dump_rules_start,
.dump = nf_tables_dump_rules,
.done = nf_tables_dump_rules_done,
.module = THIS_MODULE,
+ .data = (void *)nla,
};
- if (nla[NFTA_RULE_TABLE] || nla[NFTA_RULE_CHAIN]) {
- struct nft_rule_dump_ctx *ctx;
-
- ctx = kzalloc(sizeof(*ctx), GFP_ATOMIC);
- if (!ctx)
- return -ENOMEM;
-
- if (nla[NFTA_RULE_TABLE]) {
- ctx->table = nla_strdup(nla[NFTA_RULE_TABLE],
- GFP_ATOMIC);
- if (!ctx->table) {
- kfree(ctx);
- return -ENOMEM;
- }
- }
- if (nla[NFTA_RULE_CHAIN]) {
- ctx->chain = nla_strdup(nla[NFTA_RULE_CHAIN],
- GFP_ATOMIC);
- if (!ctx->chain) {
- kfree(ctx->table);
- kfree(ctx);
- return -ENOMEM;
- }
- }
- c.data = ctx;
- }
-
return nft_netlink_dump_start_rcu(nlsk, skb, nlh, &c);
}
@@ -3181,6 +3189,18 @@ static int nf_tables_dump_sets(struct sk_buff *skb, struct netlink_callback *cb)
return skb->len;
}
+static int nf_tables_dump_sets_start(struct netlink_callback *cb)
+{
+ struct nft_ctx *ctx_dump = NULL;
+
+ ctx_dump = kmemdup(cb->data, sizeof(*ctx_dump), GFP_ATOMIC);
+ if (ctx_dump == NULL)
+ return -ENOMEM;
+
+ cb->data = ctx_dump;
+ return 0;
+}
+
static int nf_tables_dump_sets_done(struct netlink_callback *cb)
{
kfree(cb->data);
@@ -3208,18 +3228,12 @@ static int nf_tables_getset(struct net *net, struct sock *nlsk,
if (nlh->nlmsg_flags & NLM_F_DUMP) {
struct netlink_dump_control c = {
+ .start = nf_tables_dump_sets_start,
.dump = nf_tables_dump_sets,
.done = nf_tables_dump_sets_done,
+ .data = &ctx,
.module = THIS_MODULE,
};
- struct nft_ctx *ctx_dump;
-
- ctx_dump = kmalloc(sizeof(*ctx_dump), GFP_ATOMIC);
- if (ctx_dump == NULL)
- return -ENOMEM;
-
- *ctx_dump = ctx;
- c.data = ctx_dump;
return nft_netlink_dump_start_rcu(nlsk, skb, nlh, &c);
}
@@ -3869,6 +3883,15 @@ static int nf_tables_dump_set(struct sk_buff *skb, struct netlink_callback *cb)
return -ENOSPC;
}
+static int nf_tables_dump_set_start(struct netlink_callback *cb)
+{
+ struct nft_set_dump_ctx *dump_ctx = cb->data;
+
+ cb->data = kmemdup(dump_ctx, sizeof(*dump_ctx), GFP_ATOMIC);
+
+ return cb->data ? 0 : -ENOMEM;
+}
+
static int nf_tables_dump_set_done(struct netlink_callback *cb)
{
kfree(cb->data);
@@ -4022,20 +4045,17 @@ static int nf_tables_getsetelem(struct net *net, struct sock *nlsk,
if (nlh->nlmsg_flags & NLM_F_DUMP) {
struct netlink_dump_control c = {
+ .start = nf_tables_dump_set_start,
.dump = nf_tables_dump_set,
.done = nf_tables_dump_set_done,
.module = THIS_MODULE,
};
- struct nft_set_dump_ctx *dump_ctx;
-
- dump_ctx = kmalloc(sizeof(*dump_ctx), GFP_ATOMIC);
- if (!dump_ctx)
- return -ENOMEM;
-
- dump_ctx->set = set;
- dump_ctx->ctx = ctx;
+ struct nft_set_dump_ctx dump_ctx = {
+ .set = set,
+ .ctx = ctx,
+ };
- c.data = dump_ctx;
+ c.data = &dump_ctx;
return nft_netlink_dump_start_rcu(nlsk, skb, nlh, &c);
}
@@ -4995,38 +5015,42 @@ static int nf_tables_dump_obj(struct sk_buff *skb, struct netlink_callback *cb)
return skb->len;
}
-static int nf_tables_dump_obj_done(struct netlink_callback *cb)
+static int nf_tables_dump_obj_start(struct netlink_callback *cb)
{
- struct nft_obj_filter *filter = cb->data;
+ const struct nlattr * const *nla = cb->data;
+ struct nft_obj_filter *filter = NULL;
- if (filter) {
- kfree(filter->table);
- kfree(filter);
+ if (nla[NFTA_OBJ_TABLE] || nla[NFTA_OBJ_TYPE]) {
+ filter = kzalloc(sizeof(*filter), GFP_ATOMIC);
+ if (!filter)
+ return -ENOMEM;
+
+ if (nla[NFTA_OBJ_TABLE]) {
+ filter->table = nla_strdup(nla[NFTA_OBJ_TABLE], GFP_ATOMIC);
+ if (!filter->table) {
+ kfree(filter);
+ return -ENOMEM;
+ }
+ }
+
+ if (nla[NFTA_OBJ_TYPE])
+ filter->type = ntohl(nla_get_be32(nla[NFTA_OBJ_TYPE]));
}
+ cb->data = filter;
return 0;
}
-static struct nft_obj_filter *
-nft_obj_filter_alloc(const struct nlattr * const nla[])
+static int nf_tables_dump_obj_done(struct netlink_callback *cb)
{
- struct nft_obj_filter *filter;
-
- filter = kzalloc(sizeof(*filter), GFP_ATOMIC);
- if (!filter)
- return ERR_PTR(-ENOMEM);
+ struct nft_obj_filter *filter = cb->data;
- if (nla[NFTA_OBJ_TABLE]) {
- filter->table = nla_strdup(nla[NFTA_OBJ_TABLE], GFP_ATOMIC);
- if (!filter->table) {
- kfree(filter);
- return ERR_PTR(-ENOMEM);
- }
+ if (filter) {
+ kfree(filter->table);
+ kfree(filter);
}
- if (nla[NFTA_OBJ_TYPE])
- filter->type = ntohl(nla_get_be32(nla[NFTA_OBJ_TYPE]));
- return filter;
+ return 0;
}
/* called with rcu_read_lock held */
@@ -5047,21 +5071,13 @@ static int nf_tables_getobj(struct net *net, struct sock *nlsk,
if (nlh->nlmsg_flags & NLM_F_DUMP) {
struct netlink_dump_control c = {
+ .start = nf_tables_dump_obj_start,
.dump = nf_tables_dump_obj,
.done = nf_tables_dump_obj_done,
.module = THIS_MODULE,
+ .data = (void *)nla,
};
- if (nla[NFTA_OBJ_TABLE] ||
- nla[NFTA_OBJ_TYPE]) {
- struct nft_obj_filter *filter;
-
- filter = nft_obj_filter_alloc(nla);
- if (IS_ERR(filter))
- return -ENOMEM;
-
- c.data = filter;
- }
return nft_netlink_dump_start_rcu(nlsk, skb, nlh, &c);
}
@@ -5667,37 +5683,39 @@ static int nf_tables_dump_flowtable(struct sk_buff *skb,
return skb->len;
}
-static int nf_tables_dump_flowtable_done(struct netlink_callback *cb)
+static int nf_tables_dump_flowtable_start(struct netlink_callback *cb)
{
- struct nft_flowtable_filter *filter = cb->data;
+ const struct nlattr * const *nla = cb->data;
+ struct nft_flowtable_filter *filter = NULL;
- if (!filter)
- return 0;
+ if (nla[NFTA_FLOWTABLE_TABLE]) {
+ filter = kzalloc(sizeof(*filter), GFP_ATOMIC);
+ if (!filter)
+ return -ENOMEM;
- kfree(filter->table);
- kfree(filter);
+ filter->table = nla_strdup(nla[NFTA_FLOWTABLE_TABLE],
+ GFP_ATOMIC);
+ if (!filter->table) {
+ kfree(filter);
+ return -ENOMEM;
+ }
+ }
+ cb->data = filter;
return 0;
}
-static struct nft_flowtable_filter *
-nft_flowtable_filter_alloc(const struct nlattr * const nla[])
+static int nf_tables_dump_flowtable_done(struct netlink_callback *cb)
{
- struct nft_flowtable_filter *filter;
+ struct nft_flowtable_filter *filter = cb->data;
- filter = kzalloc(sizeof(*filter), GFP_ATOMIC);
if (!filter)
- return ERR_PTR(-ENOMEM);
+ return 0;
- if (nla[NFTA_FLOWTABLE_TABLE]) {
- filter->table = nla_strdup(nla[NFTA_FLOWTABLE_TABLE],
- GFP_ATOMIC);
- if (!filter->table) {
- kfree(filter);
- return ERR_PTR(-ENOMEM);
- }
- }
- return filter;
+ kfree(filter->table);
+ kfree(filter);
+
+ return 0;
}
/* called with rcu_read_lock held */
@@ -5717,20 +5735,13 @@ static int nf_tables_getflowtable(struct net *net, struct sock *nlsk,
if (nlh->nlmsg_flags & NLM_F_DUMP) {
struct netlink_dump_control c = {
+ .start = nf_tables_dump_flowtable_start,
.dump = nf_tables_dump_flowtable,
.done = nf_tables_dump_flowtable_done,
.module = THIS_MODULE,
+ .data = (void *)nla,
};
- if (nla[NFTA_FLOWTABLE_TABLE]) {
- struct nft_flowtable_filter *filter;
-
- filter = nft_flowtable_filter_alloc(nla);
- if (IS_ERR(filter))
- return -ENOMEM;
-
- c.data = filter;
- }
return nft_netlink_dump_start_rcu(nlsk, skb, nlh, &c);
}
--
2.16.4
--
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