[PATCH net] ipv6: fix memory leak with multiple tables during netns destruction

Subsystems: networking [general], networking [ipv4/ipv6], the rest

STALE3286d

7 messages, 4 authors, 2017-09-08 · open the first message on its own page

[PATCH net] ipv6: fix memory leak with multiple tables during netns destruction

From: Sabrina Dubroca <sd@queasysnail.net>
Date: 2017-09-08 08:26:27

fib6_net_exit only frees the main and local tables. If another table was
created with fib6_alloc_table, we leak it when the netns is destroyed.

Fix this in the same way ip_fib_net_exit cleans up tables, by walking
through the whole hashtable of fib6_table's. We can get rid of the
special cases for local and main, since they're also part of the
hashtable.

Reproducer:
    ip netns add x
    ip -net x -6 rule add from 6003:1::/64 table 100
    ip netns del x

Reported-by: Jianlin Shi <redacted>
Fixes: 58f09b78b730 ("[NETNS][IPV6] ip6_fib - make it per network namespace")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
---
 net/ipv6/ip6_fib.c | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index a3b5c163325f..8280172c806c 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c

@@ -191,6 +191,12 @@ void rt6_free_pcpu(struct rt6_info *non_pcpu_rt)
 }
 EXPORT_SYMBOL_GPL(rt6_free_pcpu);
 
+static void fib6_free_table(struct fib6_table *table)
+{
+	inetpeer_invalidate_tree(&table->tb6_peers);
+	kfree(table);
+}
+
 static void fib6_link_table(struct net *net, struct fib6_table *tb)
 {
 	unsigned int h;

@@ -2022,15 +2028,22 @@ static int __net_init fib6_net_init(struct net *net)
 
 static void fib6_net_exit(struct net *net)
 {
+	unsigned int i;
+
 	rt6_ifdown(net, NULL);
 	del_timer_sync(&net->ipv6.ip6_fib_timer);
 
-#ifdef CONFIG_IPV6_MULTIPLE_TABLES
-	inetpeer_invalidate_tree(&net->ipv6.fib6_local_tbl->tb6_peers);
-	kfree(net->ipv6.fib6_local_tbl);
-#endif
-	inetpeer_invalidate_tree(&net->ipv6.fib6_main_tbl->tb6_peers);
-	kfree(net->ipv6.fib6_main_tbl);
+	for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
+		struct hlist_head *head = &net->ipv6.fib_table_hash[i];
+		struct hlist_node *tmp;
+		struct fib6_table *tb;
+
+		hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) {
+			hlist_del(&tb->tb6_hlist);
+			fib6_free_table(tb);
+		}
+	}
+
 	kfree(net->ipv6.fib_table_hash);
 	kfree(net->ipv6.rt6_stats);
 	fib6_notifier_exit(net);

-- 
2.14.1

Re: [PATCH net] ipv6: fix memory leak with multiple tables during netns destruction

From: David Miller <davem@davemloft.net>
Date: 2017-09-08 16:49:19

From: Sabrina Dubroca <sd@queasysnail.net>
Date: Fri,  8 Sep 2017 10:26:19 +0200

fib6_net_exit only frees the main and local tables. If another table was
created with fib6_alloc_table, we leak it when the netns is destroyed.

Fix this in the same way ip_fib_net_exit cleans up tables, by walking
through the whole hashtable of fib6_table's. We can get rid of the
special cases for local and main, since they're also part of the
hashtable.

Reproducer:
    ip netns add x
    ip -net x -6 rule add from 6003:1::/64 table 100
    ip netns del x

Reported-by: Jianlin Shi <redacted>
Fixes: 58f09b78b730 ("[NETNS][IPV6] ip6_fib - make it per network namespace")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>

Applied and queued up for -stable, thanks.

Re: [PATCH net] ipv6: fix memory leak with multiple tables during netns destruction

From: Eric Dumazet <hidden>
Date: 2017-09-08 17:59:54

On Fri, 2017-09-08 at 10:26 +0200, Sabrina Dubroca wrote:

quoted hunk

fib6_net_exit only frees the main and local tables. If another table was
created with fib6_alloc_table, we leak it when the netns is destroyed.

Fix this in the same way ip_fib_net_exit cleans up tables, by walking
through the whole hashtable of fib6_table's. We can get rid of the
special cases for local and main, since they're also part of the
hashtable.

Reproducer:
    ip netns add x
    ip -net x -6 rule add from 6003:1::/64 table 100
    ip netns del x

Reported-by: Jianlin Shi <redacted>
Fixes: 58f09b78b730 ("[NETNS][IPV6] ip6_fib - make it per network namespace")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
---
 net/ipv6/ip6_fib.c | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index a3b5c163325f..8280172c806c 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c

@@ -191,6 +191,12 @@ void rt6_free_pcpu(struct rt6_info *non_pcpu_rt)
 }
 EXPORT_SYMBOL_GPL(rt6_free_pcpu);
 
+static void fib6_free_table(struct fib6_table *table)
+{
+	inetpeer_invalidate_tree(&table->tb6_peers);
+	kfree(table);
+}
+
 static void fib6_link_table(struct net *net, struct fib6_table *tb)
 {
 	unsigned int h;

@@ -2022,15 +2028,22 @@ static int __net_init fib6_net_init(struct net *net)
 
 static void fib6_net_exit(struct net *net)
 {
+	unsigned int i;
+
 	rt6_ifdown(net, NULL);
 	del_timer_sync(&net->ipv6.ip6_fib_timer);
 
-#ifdef CONFIG_IPV6_MULTIPLE_TABLES
-	inetpeer_invalidate_tree(&net->ipv6.fib6_local_tbl->tb6_peers);
-	kfree(net->ipv6.fib6_local_tbl);
-#endif
-	inetpeer_invalidate_tree(&net->ipv6.fib6_main_tbl->tb6_peers);
-	kfree(net->ipv6.fib6_main_tbl);
+	for (i = 0; i < FIB_TABLE_HASHSZ; i++) {

should not this be FIB6_TABLE_HASHSZ ?

+		struct hlist_head *head = &net->ipv6.fib_table_hash[i];
+		struct hlist_node *tmp;
+		struct fib6_table *tb;
+
+		hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) {
+			hlist_del(&tb->tb6_hlist);
+			fib6_free_table(tb);
+		}
+	}
+
 	kfree(net->ipv6.fib_table_hash);
 	kfree(net->ipv6.rt6_stats);
 	fib6_notifier_exit(net);

Re: [PATCH net] ipv6: fix memory leak with multiple tables during netns destruction

From: Cong Wang <hidden>
Date: 2017-09-08 18:24:56

On Fri, Sep 8, 2017 at 1:26 AM, Sabrina Dubroca [off-list ref] wrote:

quoted hunk

fib6_net_exit only frees the main and local tables. If another table was
created with fib6_alloc_table, we leak it when the netns is destroyed.

Fix this in the same way ip_fib_net_exit cleans up tables, by walking
through the whole hashtable of fib6_table's. We can get rid of the
special cases for local and main, since they're also part of the
hashtable.

Reproducer:
    ip netns add x
    ip -net x -6 rule add from 6003:1::/64 table 100
    ip netns del x

Reported-by: Jianlin Shi <redacted>
Fixes: 58f09b78b730 ("[NETNS][IPV6] ip6_fib - make it per network namespace")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
---
 net/ipv6/ip6_fib.c | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index a3b5c163325f..8280172c806c 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c

@@ -191,6 +191,12 @@ void rt6_free_pcpu(struct rt6_info *non_pcpu_rt)
 }
 EXPORT_SYMBOL_GPL(rt6_free_pcpu);

+static void fib6_free_table(struct fib6_table *table)
+{
+       inetpeer_invalidate_tree(&table->tb6_peers);
+       kfree(table);
+}
+
 static void fib6_link_table(struct net *net, struct fib6_table *tb)
 {
        unsigned int h;

@@ -2022,15 +2028,22 @@ static int __net_init fib6_net_init(struct net *net)

 static void fib6_net_exit(struct net *net)
 {
+       unsigned int i;
+
        rt6_ifdown(net, NULL);
        del_timer_sync(&net->ipv6.ip6_fib_timer);

-#ifdef CONFIG_IPV6_MULTIPLE_TABLES
-       inetpeer_invalidate_tree(&net->ipv6.fib6_local_tbl->tb6_peers);
-       kfree(net->ipv6.fib6_local_tbl);
-#endif
-       inetpeer_invalidate_tree(&net->ipv6.fib6_main_tbl->tb6_peers);
-       kfree(net->ipv6.fib6_main_tbl);
+       for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
+               struct hlist_head *head = &net->ipv6.fib_table_hash[i];
+               struct hlist_node *tmp;
+               struct fib6_table *tb;
+
+               hlist_for_each_entry_safe(tb, tmp, head, tb6_hlist) {
+                       hlist_del(&tb->tb6_hlist);

hlist_del_rcu() ?

+                       fib6_free_table(tb);

kfree_rcu() in fib6_free_table()?

+               }
+       }
+
        kfree(net->ipv6.fib_table_hash);
        kfree(net->ipv6.rt6_stats);
        fib6_notifier_exit(net);
--
2.14.1

[PATCH net] ipv6: fix typo in fib6_net_exit()

From: Eric Dumazet <hidden>
Date: 2017-09-08 22:48:50

From: Eric Dumazet <edumazet@google.com>

IPv6 FIB should use FIB6_TABLE_HASHSZ, not FIB_TABLE_HASHSZ.

Fixes: ba1cc08d9488 ("ipv6: fix memory leak with multiple tables during netns destruction")
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/ipv6/ip6_fib.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 8280172c806ca47c5ca4aef723d405a0a8d7df2a..e5308d7cbd75c4fb67861082382122d445cf5b74 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c

@@ -2033,7 +2033,7 @@ static void fib6_net_exit(struct net *net)
 	rt6_ifdown(net, NULL);
 	del_timer_sync(&net->ipv6.ip6_fib_timer);
 
-	for (i = 0; i < FIB_TABLE_HASHSZ; i++) {
+	for (i = 0; i < FIB6_TABLE_HASHSZ; i++) {
 		struct hlist_head *head = &net->ipv6.fib_table_hash[i];
 		struct hlist_node *tmp;
 		struct fib6_table *tb;

Re: [PATCH net] ipv6: fix typo in fib6_net_exit()

From: David Miller <davem@davemloft.net>
Date: 2017-09-08 23:09:28

From: Eric Dumazet <redacted>
Date: Fri, 08 Sep 2017 15:48:47 -0700

From: Eric Dumazet <edumazet@google.com>

IPv6 FIB should use FIB6_TABLE_HASHSZ, not FIB_TABLE_HASHSZ.

Fixes: ba1cc08d9488 ("ipv6: fix memory leak with multiple tables during netns destruction")
Signed-off-by: Eric Dumazet <edumazet@google.com>

Applied.

Re: [PATCH net] ipv6: fix typo in fib6_net_exit()

From: Sabrina Dubroca <sd@queasysnail.net>
Date: 2017-09-08 23:10:01

2017-09-08, 15:48:47 -0700, Eric Dumazet wrote:

From: Eric Dumazet <edumazet@google.com>

IPv6 FIB should use FIB6_TABLE_HASHSZ, not FIB_TABLE_HASHSZ.

Fixes: ba1cc08d9488 ("ipv6: fix memory leak with multiple tables during netns destruction")
Signed-off-by: Eric Dumazet <edumazet@google.com>

Ouch, yes :(
Thanks for the fix.

Acked-by: Sabrina Dubroca <sd@queasysnail.net>

-- 
Sabrina

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