From 5f41ae6fca9d40ab3cb9b0507931ef7a9b3ea50b Mon Sep 17 00:00:00 2001 From: Jeremy Kerr Date: Tue, 24 Jan 2023 10:01:04 +0800 Subject: [PATCH] net: mctp: move expiry timer delete to unhash Currently, we delete the key expiry timer (in sk->close) before unhashing the sk. This means that another thread may find the sk through its presence on the key list, and re-queue the timer. This change moves the timer deletion to the unhash, after we have made the key no longer observable, so the timer cannot be re-queued. Fixes: 7b14e15ae6f4 ("mctp: Implement a timeout for tags") Signed-off-by: Jeremy Kerr Signed-off-by: David S. Miller --- net/mctp/af_mctp.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/net/mctp/af_mctp.c b/net/mctp/af_mctp.c index fc9e728b6333..fb6ae3110528 100644 --- a/net/mctp/af_mctp.c +++ b/net/mctp/af_mctp.c @@ -544,9 +544,6 @@ static int mctp_sk_init(struct sock *sk) static void mctp_sk_close(struct sock *sk, long timeout) { - struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk); - - del_timer_sync(&msk->key_expiry); sk_common_release(sk); } @@ -581,6 +578,12 @@ static void mctp_sk_unhash(struct sock *sk) __mctp_key_remove(key, net, fl2, MCTP_TRACE_KEY_CLOSED); } spin_unlock_irqrestore(&net->mctp.keys_lock, flags); + + /* Since there are no more tag allocations (we have removed all of the + * keys), stop any pending expiry events. the timer cannot be re-queued + * as the sk is no longer observable + */ + del_timer_sync(&msk->key_expiry); } static struct proto mctp_proto = {