This is a note to let you know that I've just added the patch titled inet_diag: annotate data-races around inet_diag_table[] to the 6.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: inet_diag-annotate-data-races-around-inet_diag_table.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit b05e00f391de68fe7d481a989e85873f74a1ac8f Author: Eric Dumazet <edumazet@xxxxxxxxxx> Date: Mon Jan 22 11:25:56 2024 +0000 inet_diag: annotate data-races around inet_diag_table[] [ Upstream commit e50e10ae5d81ddb41547114bfdc5edc04422f082 ] inet_diag_lock_handler() reads inet_diag_table[proto] locklessly. Use READ_ONCE()/WRITE_ONCE() annotations to avoid potential issues. Fixes: d523a328fb02 ("[INET]: Fix inet_diag dead-lock regression") Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Reviewed-by: Guillaume Nault <gnault@xxxxxxxxxx> Reviewed-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx> Reviewed-by: Willem de Bruijn <willemb@xxxxxxxxxx> Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c index e13a84433413e..132b10e23758b 100644 --- a/net/ipv4/inet_diag.c +++ b/net/ipv4/inet_diag.c @@ -57,7 +57,7 @@ static const struct inet_diag_handler *inet_diag_lock_handler(int proto) return ERR_PTR(-ENOENT); } - if (!inet_diag_table[proto]) + if (!READ_ONCE(inet_diag_table[proto])) sock_load_diag_module(AF_INET, proto); mutex_lock(&inet_diag_table_mutex); @@ -1419,7 +1419,7 @@ int inet_diag_register(const struct inet_diag_handler *h) mutex_lock(&inet_diag_table_mutex); err = -EEXIST; if (!inet_diag_table[type]) { - inet_diag_table[type] = h; + WRITE_ONCE(inet_diag_table[type], h); err = 0; } mutex_unlock(&inet_diag_table_mutex); @@ -1436,7 +1436,7 @@ void inet_diag_unregister(const struct inet_diag_handler *h) return; mutex_lock(&inet_diag_table_mutex); - inet_diag_table[type] = NULL; + WRITE_ONCE(inet_diag_table[type], NULL); mutex_unlock(&inet_diag_table_mutex); } EXPORT_SYMBOL_GPL(inet_diag_unregister);