From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8067825393E; Tue, 25 Aug 2026 13:58:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787666294; cv=none; b=rf07a3BA8vaXWLC1AIqetRdyugUJYlOfw/TsSNrpDqcz55x/IQyilnCXlrfNnLLS345TOMWYzwjTuHY2rYd5AVMTkB/6dcx65iDUmJsXUMgKpGalglJwfdan9DKQoj/0MSPog8jx6IzO9fjfSjtfjzhvQlpaAK6FOrR6hFeG4Jg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787666294; c=relaxed/simple; bh=W9z6XA/pSmqIa9nNNNk0hwtjndWtv+LKz94G7iW1pR4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qfUk8Uml/l9zZ/lpEuPJxzh6nDAsSTEHhWOgeQpw5ho2k24j1jCQuk2hOAtHLb4bHfvoOZuAejXwYVAogcAyMjJi7/DQ23o5+9fPLVD+iZE0j0vNyhcyYS2lPo1oYloohERzhJKe+4qfNmTKhoR7t5PaW2bGNnZHxByf1O72XWw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=jEUMMREy; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="jEUMMREy" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D52ED1F00A3D; Tue, 25 Aug 2026 13:58:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1787666293; bh=o7cmlDTKNzviJsbS0lOvLHZ7L7T/ejPBsGur8t3Aim8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=jEUMMREyiQkuNuoRLEnK8hJGlv8bmS6UQIll+XU5Vmlr1XkXDZETQdUatwBz3mACJ jcFxinMO5qP5nAqzgHulTjnRiLsGuY2/JaetL/pyOCsCqAEdh6XPilNW3r3w4SWZ+V W7vcU0noJkBXX1qO6ZSnAf3dsUtZLaEoIH2FVNoQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Mat Martineau , "Matthieu Baerts (NGI0)" , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.15 70/76] mptcp: pm: ADD_ADDR rtx: free sk if last Date: Tue, 25 Aug 2026 15:27:03 +0200 Message-ID: <20260825132544.301715728@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260825132541.568214149@linuxfoundation.org> References: <20260825132541.568214149@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Matthieu Baerts (NGI0)" [ Upstream commit b7b9a461569734d33d3259d58d2507adfac107ed ] When an ADD_ADDR is retransmitted, the sk is held in sk_reset_timer(), and released at the end. If at that moment, it was the last reference being held, the sk would not be freed. sock_put() should then be called instead of __sock_put(). But that's not enough: if it is the last reference, sock_put() will call sk_free(), which will end up calling sk_stop_timer_sync() on the same timer, and waiting indefinitely to finish. So it is needed to mark that the timer is done at the end of the timer handler when it has not been rescheduled, not to call sk_stop_timer_sync() on "itself". Fixes: 00cfd77b9063 ("mptcp: retransmit ADD_ADDR when timeout") Cc: stable@vger.kernel.org Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-5-fca8091060a4@kernel.org Signed-off-by: Jakub Kicinski Stable-dep-of: a7aad5b69d3b ("mptcp: pm: fix data race in add_addr timer callback") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/mptcp/pm_netlink.c | 28 +++++++++++++++++----------- 1 file changed, 17 insertions(+), 11 deletions(-) --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -36,6 +36,7 @@ struct mptcp_pm_add_entry { struct timer_list add_timer; struct mptcp_sock *sock; u8 retrans_times; + bool timer_done; struct rcu_head rcu; }; @@ -316,22 +317,22 @@ static void mptcp_pm_add_timer(struct ti struct mptcp_pm_add_entry *entry = from_timer(entry, timer, add_timer); struct mptcp_sock *msk = entry->sock; struct sock *sk = (struct sock *)msk; - unsigned int timeout; + unsigned int timeout = 0; pr_debug("msk=%p\n", msk); + bh_lock_sock(sk); if (unlikely(inet_sk_state_load(sk) == TCP_CLOSE)) - goto exit; + goto out; - bh_lock_sock(sk); if (sock_owned_by_user(sk)) { /* Try again later. */ - sk_reset_timer(sk, timer, jiffies + HZ / 20); + timeout = HZ / 20; goto out; } if (mptcp_pm_should_add_signal_addr(msk)) { - sk_reset_timer(sk, timer, jiffies + HZ); + timeout = HZ; goto out; } @@ -354,9 +355,8 @@ static void mptcp_pm_add_timer(struct ti entry->retrans_times++; } - if (entry->retrans_times < ADD_ADDR_RETRANS_MAX) - sk_reset_timer(sk, timer, - jiffies + timeout); + if (entry->retrans_times >= ADD_ADDR_RETRANS_MAX) + timeout = 0; spin_unlock_bh(&msk->pm.lock); @@ -364,9 +364,13 @@ static void mptcp_pm_add_timer(struct ti mptcp_pm_subflow_established(msk); out: + if (timeout) + sk_reset_timer(sk, timer, jiffies + timeout); + else + /* if sock_put calls sk_free: avoid waiting for this timer */ + entry->timer_done = true; bh_unlock_sock(sk); -exit: - __sock_put(sk); + sock_put(sk); } struct mptcp_pm_add_entry * @@ -427,6 +431,7 @@ static bool mptcp_pm_alloc_anno_list(str add_entry->retrans_times = 0; timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0); + add_entry->timer_done = false; timeout = mptcp_get_add_addr_timeout(net); if (timeout) sk_reset_timer(sk, &add_entry->add_timer, jiffies + timeout); @@ -447,7 +452,8 @@ void mptcp_pm_free_anno_list(struct mptc spin_unlock_bh(&msk->pm.lock); list_for_each_entry_safe(entry, tmp, &free_list, list) { - sk_stop_timer_sync(sk, &entry->add_timer); + if (!entry->timer_done) + sk_stop_timer_sync(sk, &entry->add_timer); kfree_rcu(entry, rcu); } }