diff options
| author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2025-04-17 17:03:53 -0700 |
|---|---|---|
| committer | Paolo Abeni <pabeni@redhat.com> | 2025-04-24 09:29:56 +0200 |
| commit | 834d97843e3bca86f17cc517885f54f3433427b2 (patch) | |
| tree | c6a14d4410eef5584c0111a7f6e3ab46f6e23732 /net | |
| parent | 71c0efb6d12f4c734b2a894c17e84ebab49b4c60 (diff) | |
ipv6: Protect fib6_link_table() with spinlock.
We will get rid of RTNL from RTM_NEWROUTE and SIOCADDRT.
If the request specifies a new table ID, fib6_new_table() is
called to create a new routing table.
Two concurrent requests could specify the same table ID, so we
need a lock to protect net->ipv6.fib_table_hash[h].
Let's add a spinlock to protect the hash bucket linkage.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://patch.msgid.link/20250418000443.43734-13-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv6/ip6_fib.c | 26 |
1 files changed, 21 insertions, 5 deletions
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index bf727149fdec..79b672f3fc53 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -249,19 +249,33 @@ static struct fib6_table *fib6_alloc_table(struct net *net, u32 id) struct fib6_table *fib6_new_table(struct net *net, u32 id) { - struct fib6_table *tb; + struct fib6_table *tb, *new_tb; if (id == 0) id = RT6_TABLE_MAIN; + tb = fib6_get_table(net, id); if (tb) return tb; - tb = fib6_alloc_table(net, id); - if (tb) - fib6_link_table(net, tb); + new_tb = fib6_alloc_table(net, id); + if (!new_tb) + return NULL; + + spin_lock_bh(&net->ipv6.fib_table_hash_lock); + + tb = fib6_get_table(net, id); + if (unlikely(tb)) { + spin_unlock_bh(&net->ipv6.fib_table_hash_lock); + kfree(new_tb); + return tb; + } - return tb; + fib6_link_table(net, new_tb); + + spin_unlock_bh(&net->ipv6.fib_table_hash_lock); + + return new_tb; } EXPORT_SYMBOL_GPL(fib6_new_table); @@ -2423,6 +2437,8 @@ static int __net_init fib6_net_init(struct net *net) if (!net->ipv6.fib_table_hash) goto out_rt6_stats; + spin_lock_init(&net->ipv6.fib_table_hash_lock); + net->ipv6.fib6_main_tbl = kzalloc(sizeof(*net->ipv6.fib6_main_tbl), GFP_KERNEL); if (!net->ipv6.fib6_main_tbl) |