From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=213.160.73.56 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794481062; b=cSQRNqknHrON0Ue4ZC5Nonbo2JPLhvitwY7OvqwtqIggXRSSrBRZvo9PuP+qJchOHRhd aLcz258rZLKbjDxc09BL/NcMtsny5G2nJ/u62587+LwsCdOTSNmIp5a6KJRJ+lJujvdtL EQ2k8WUBUkwEKtv5QP0GXXqopM7gyNgr+P9HLZeMQi+5Iq3ZrtQJBiesdzD3SsOFVdXRi AP6wbmDsvru9GviXW6ms6YKlaqObhTpBoDd2AnjzJinaAGo2G+odHIxJZLA0vLNMGPscs Wj6V5nbJoYtB5Q24ct+NZCNb7jytqrsRDD7W1HTTbzsNvCLGVxiZMl3mDu0yrixDrlQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794481062; h=DMARC-Filter:Received:DKIM-Signature:From:To:Subject:Date:Message-ID: In-Reply-To:References:MIME-Version:Content-Type; bh=8P9ng6dnAOZ1uLRwI2Xyior8nl1Uol/mP/8AoZqdZUo=; b=WARinW6u+uXojqxRDImtfW6YdKbswKZmQG7uWGtRce3NnESFJ/MQ4gWTaG8R5k1/Oy2f zjcRA0+B1ZbsRg0ePltcc/eV8yFPsMCm40YngGgbAgYUyuWAUdPPYc8QNSgw6fxKpK0aj XgmNg7rixbYqDvQigyPLI5GFoekGu2YU4LzvnN3SvNEUnBSHFw1CA9rO7MCgVGFD8obig h7M6rqUnYv48Wdgw1xDMCUlKthF8YKZEN7b1zICT1BSCgGUEzOOzi8j8f8ZgrOniFD7R/ Ehyz9g9Nk1txAt8t/tMDEs4SztkpJpHZEoSghn3ckb8WqWY7OG3+whJUPXslz1WyjBQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=narfation.org; spf=pass smtp.mailfrom=narfation.org; dkim=pass header.d=narfation.org header.i=@narfation.org header.a=rsa-sha256 header.s=20121 header.b=aZBIcGHd; arc=none smtp.remote-ip=213.160.73.56 Received: from dvalin.narfation.org (dvalin.narfation.org [213.160.73.56]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 21F3E606A31C for ; Thu, 12 Nov 2026 10:57:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 21F3E606A31C Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=narfation.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=narfation.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=narfation.org header.i=@narfation.org header.a=rsa-sha256 header.s=20121 header.b=aZBIcGHd Received: by dvalin.narfation.org (Postfix) id 46F7F1FEF7; Thu, 12 Nov 2026 10:57:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=narfation.org; s=20121; t=1794481060; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=8P9ng6dnAOZ1uLRwI2Xyior8nl1Uol/mP/8AoZqdZUo=; b=aZBIcGHdgmTgfk0JcPXJLdRysccdxIvZ/gaPvXpts6Ofv5Y3eOzvbwWlk3Cs5A0WFSNdlC aXjzjLzKCOIB85shL/DCf4ggsC9869mYZ9NSWOp2K5ht2NFUHFIfa1J1JkBsqpC+2fk3dO uiewdbMYQkq+6nYDyjZ4z8TL97QIwfo= From: Sven Eckelmann To: sashiko-reviews@lists.linux.dev, b.a.t.m.a.n@lists.open-mesh.org, netdev@vger.kernel.org Subject: Re: [PATCH net-next 09/15] batman-adv: annotate originator last_seen with READ/WRITE_ONCE Date: Thu, 12 Nov 2026 11:57:37 +0100 Message-ID: <1831685.QkHrqEjB74@ripper> In-Reply-To: References: <20261111102729.2096241-1-sw@simonwunderlich.de> <20261111102729.2096241-10-sw@simonwunderlich.de> X-Mailing-List: netdev@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart4751616.8F6SAcFxjW"; micalg="pgp-sha512"; protocol="application/pgp-signature" --nextPart4751616.8F6SAcFxjW Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8"; protected-headers="v1" From: Sven Eckelmann Date: Thu, 12 Nov 2026 11:57:37 +0100 Message-ID: <1831685.QkHrqEjB74@ripper> In-Reply-To: MIME-Version: 1.0 On Thursday, 12 November 2026 11:34:43 CET sashiko-bot@kernel.org wrote: [...] > [Severity: Medium] > This problem wasn't introduced by this patch, but can > batadv_v_neigh_dump_neigh() and batadv_iv_neigh_dump_neigh() batadv_iv_neigh_dump_neigh? There is no function with this name in the source code. There is only batadv_iv_ogm_neigh_dump_neigh() > suffer from > the same timestamp underflow [1]? > > net/batman-adv/bat_v.c:batadv_v_neigh_dump_neigh() { > ... > last_seen_msecs = jiffies_to_msecs(jiffies - hardif_neigh->last_seen); > ... > } > > Because hardif_neigh->last_seen is updated locklessly on packet reception > and read without READ_ONCE() or jiffies_delta_to_msecs(), a concurrent > update can leave hardif_neigh->last_seen ahead of the sampled jiffies > value, wrapping the subtraction and exporting a huge last_seen_msecs > value over netlink. This is adjusted in the next two patches in this patchset. Regards, Sven --nextPart4751616.8F6SAcFxjW Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. Content-Transfer-Encoding: 7Bit -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQS81G/PswftH/OW8cVND3cr0xT1ywUCavWboQAKCRBND3cr0xT1 y30qAQCxM2pzrCpWwjtmdG17Uozu4UXuGHZ7Y558+4W2pqCO7wD/dz9ukJGdb+Jv qjF9rkCqVOr4xg+aDzhwJ5Pan1aQGww= =hGQR -----END PGP SIGNATURE----- --nextPart4751616.8F6SAcFxjW--