From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj1-f54.google.com (mail-pj1-f54.google.com [209.85.216.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D3D023FB05D for ; Fri, 5 Jun 2026 14:58:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.54 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780671494; cv=none; b=jApwDcxW81lMO0PTyHks5WWCLd6LJB8IhUjmSNiuo8Z0wRAFpD8Tn27S5mZpAEZlODu0lUcgC6GTv9TaSI068B9Nmg7ZnQ2oL7CUTe0YTjNOAi579l91LRX3MCSUsGkeOMGRPPN/1RYHAYx2/G2Rbjsojy6dmbLg8IPEjUm7p6Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780671494; c=relaxed/simple; bh=g/Vf5S/ImH9NFAJ8TFesAonWYxBfyXfhedQepyu5x4w=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=iCEPSd/O+BXU04H7Muq3/cBNIIgi7XOfNee71gwLEPLvxGHu5RlJGisaxC78PYdjPCo2q6VCQrG/SL0g2j3GTZsd18/Li8Y3NtGY7bDoEG9DqfoNMFTEOZ+sGBwZyWp0uB+LDk64qwkKNf3AH+2XLVZCjHQpuWkooZzvknyk9p0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=UAwJwzYZ; arc=none smtp.client-ip=209.85.216.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="UAwJwzYZ" Received: by mail-pj1-f54.google.com with SMTP id 98e67ed59e1d1-36d6bb38b44so1423964a91.0 for ; Fri, 05 Jun 2026 07:58:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1780671492; x=1781276292; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=g6llRc9O739ZmXHdXtpVluJELJf01erqJYXeZGoa0Iw=; b=UAwJwzYZ0v2xgArabsiWgErFmQVFXuEB+E9QobILKvEx2eZMBuV+A3LJBzjzXsRoyL 8odLsqgTRVPfhY8ZIbQdJRZtaa2lGo06dCRZhLxV3NhJTFlUIltJzLcZyzIFb5GOjyY9 RKsD86MUyMRHQkMhpP+lI4CtSXHbomDfMOWpALtC4p3ZcclhoEawcBdg20CcZ/6w94cn aEn9JQt6Z+xQxWeRc+m43867nDbX9WwjQAsFx3XY3D/fp/l1DzQZb/wNwwYQOUI8Yg98 byGrgyFgECXcKt5sx0Kbq8zkYNd88lZy1yXwCk6HdOLWUlRyypYIzYWmiezJN76mWBO1 JXBg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1780671492; x=1781276292; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to; bh=g6llRc9O739ZmXHdXtpVluJELJf01erqJYXeZGoa0Iw=; b=lG9kGVSAfwnZX6nsCJOAGfmCjBQLugMlNJm2MsVWkJ4INjOLb0cncYL84hhDK6eBQI FILsVmnIJn7mEObxxka2qGHRsZ+B9+XoaAiplAQKd7IzgMnxsQ9p4z57Vhtz08iF/DsK VSpjrlCMylslUFN6VVl18NTt+LQ7/pYoutI7HJncijcEYyAP3mLm9itGR3i7CUEPIE0y FFQvjxpqTjw1T82OkqblIg9BR+yM8iS9Zlq2PbMGL64sOjMrwaxrzPDR9XtWxF2nG7oD jXM/hLDlixYYbhxNO0deda7PaLFI3bbMNAK9iW8EoBEeJBjzYwB/xemOfg/WMBChaZEt VzsA== X-Forwarded-Encrypted: i=1; AFNElJ97gINffzFmUnfuE6+tixdgD8kySxed4Wlr2cRTTcqkkYVBZAmGXowSiNNLgn5qDpvWxhJ8l4CoCY+OAd8=@vger.kernel.org X-Gm-Message-State: AOJu0YxI52i0OICytmyTqVsvZS7eY9QfRGSi4LHVxdBl6/0373QaVvud 11TOLNnmgcjXNb4mlIFM8v27/R/qJV20E+dK2cBqRc1KD4HsNahDIpf/ X-Gm-Gg: Acq92OHAhBQGnDDkblfJLcc+7sQLbBe8UoqHDd1e84x39XJDqxBvhU8wQieIqOhHTEP 5jD65jSHgSm3uljPvIWuBXOLqvtlT9LfRvmNlwugUKmP58IXi+2PckSR2S7DUtx4h+1BvI0Pu7h x9ueFFV3hRwyF2Ks18NoE/iUqCtmCETbP0w9xN3Fhebn7pPF6b9qe+c2CPRMmX+rPD8jieQBhST BzMeHhjkEku9YugOQ2glZf4tSXAlLeJ+VJeFLuwRAHGUSBxWWKYn5VliVaFge3mesWpSvCjXAWe XSFQF0Dx8UzjlVbekDN884ss3OnYO2k25xlEzNNh9NfS27qkAzsUkOAFyf+Lw5JfYSu0UGlI+Mv 6oJFULdB9/5TssSOVbQyoZmeHv4VE3EexLO6Pr0DhymHZh8dulRAMbQy7aBqtARWRtlBdmNdWsN lLWzzaG8iYD7MDxhGF8MZCBRmZ/MmpTA6IvXFzyXBy77IdyDJcGj2X5tXUGkCvvxrg5PiojEfli x8= X-Received: by 2002:a17:90b:5827:b0:36b:a0fa:ff96 with SMTP id 98e67ed59e1d1-370ef1f2cdemr4307027a91.12.1780671492081; Fri, 05 Jun 2026 07:58:12 -0700 (PDT) Received: from m-upc-A520M-HDV.flets-east.jp ([2400:2410:3f60:500:1cda:ba68:a654:c3cf]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-36f70a28c0esm7058231a91.12.2026.06.05.07.58.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 05 Jun 2026 07:58:11 -0700 (PDT) From: Yuyang Huang To: Yuyang Huang Cc: "David S. Miller" , David Ahern , Eric Dumazet , Ido Schimmel , Jakub Kicinski , Paolo Abeni , Simon Horman , linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH net-next 2/2] ipv6: mcast: annotate igmp6 timer expiry race Date: Fri, 5 Jun 2026 23:57:59 +0900 Message-ID: <20260605145759.59639-3-sigefriedhyy@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260605145759.59639-1-sigefriedhyy@gmail.com> References: <20260605145759.59639-1-sigefriedhyy@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit /proc/net/igmp6 walks IPv6 multicast memberships under RCU and reads mca_work.timer.expires to print the remaining multicast timer. The delayed-work timer can be updated concurrently. Annotate the intentional lockless procfs snapshot with READ_ONCE(). Signed-off-by: Yuyang Huang --- net/ipv6/mcast.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c index bd3972730aa0..184e57469086 100644 --- a/net/ipv6/mcast.c +++ b/net/ipv6/mcast.c @@ -2983,6 +2983,7 @@ static int igmp6_mc_seq_show(struct seq_file *seq, void *v) { struct ifmcaddr6 *im = (struct ifmcaddr6 *)v; struct igmp6_mc_iter_state *state = igmp6_mc_seq_private(seq); + unsigned long expires = READ_ONCE(im->mca_work.timer.expires); unsigned int mca_flags = READ_ONCE(im->mca_flags); seq_printf(seq, @@ -2991,7 +2992,7 @@ static int igmp6_mc_seq_show(struct seq_file *seq, void *v) &im->mca_addr, READ_ONCE(im->mca_users), mca_flags, (mca_flags & MAF_TIMER_RUNNING) ? - jiffies_to_clock_t(im->mca_work.timer.expires - jiffies) : 0); + jiffies_to_clock_t(expires - jiffies) : 0); return 0; } -- 2.43.0