2023-11-16 02:23:00

by Minjie Du

Subject: [PATCH v2] net/tcp: use kfree_sensitive() instend of kfree() in two functions

key might contain private information, so use kfree_sensitive to free it.
In tcp_time_wait_init() and tcp_md5_twsk_free_rcu() use kfree_sensitive().

Signed-off-by: Minjie Du <[email protected]>
---
net/ipv4/tcp_minisocks.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index a9807eeb311c..83686c7e7ce9 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -281,7 +281,7 @@ static void tcp_time_wait_init(struct sock *sk, struct tcp_timewait_sock *tcptw)
return;
out_free:
WARN_ON_ONCE(1);
- kfree(tcptw->tw_md5_key);
+ kfree_sensitive(tcptw->tw_md5_key);
tcptw->tw_md5_key = NULL;
#endif
}
@@ -368,7 +368,7 @@ static void tcp_md5_twsk_free_rcu(struct rcu_head *head)
struct tcp_md5sig_key *key;

key = container_of(head, struct tcp_md5sig_key, rcu);
- kfree(key);
+ kfree_sensitive(key);
static_branch_slow_dec_deferred(&tcp_md5_needed);
tcp_md5_release_sigpool();
}
--
2.39.0

2023-11-16 08:44:31

by Eric Dumazet

Subject: Re: [PATCH v2] net/tcp: use kfree_sensitive() instend of kfree() in two functions

On Thu, Nov 16, 2023 at 3:22 AM Minjie Du <[email protected]> wrote:
>
> key might contain private information, so use kfree_sensitive to free it.
> In tcp_time_wait_init() and tcp_md5_twsk_free_rcu() use kfree_sensitive().
>
> Signed-off-by: Minjie Du <[email protected]>
> ---
>

You have not addressed my prior feedback.

3) You forgot tcp_time_wait_init(), tcp_md5_do_del(), tcp_md5_key_copy(),
tcp_md5_do_add(), tcp_clear_md5_list().