From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793336081; b=cvWZjT7+jjNJuzXKd+of9nqeJUm0zb/F90T9h/XYEEh9VJOCYLCX1Z4T8bSwmB4Sp6vt /Vk0ikzrk4vj2okESJjUwGGQxDNeqsySITm8ITNPMkIAi0kEr7smZfZnlRvlS+INVQw4y 4m7dMKl/5mP+zyQYtRulTynvehFvU4Vp5tgjcZP2nR8zEVjHIPIaZg4181iYqUTQlPay4 CnLLkYPi81CaPP7nM11jBxixuah9wsGPDLkK8fjqbZncPB/faJpQnotlytj7z2ANCj51/ 2d4ldBR0j4FyhkurS0pVkfPKejF9B6DB0lkL3RhyAhrUK1HF9Vdx2HBZtukh1yBaveA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793336081; h=Received:DKIM-Signature:Message-ID:From:Subject:Reply-To:To:Cc: In-Reply-To:References:Content-Type:Content-Transfer-Encoding:Date; bh=WZfFeDqbdcOih6qA1/0BBGjlPc+vzdZ9HbJkxb4c1zo=; b=5gGEHYLURXY0aObolyiwddko4UCGpbETiNVAdUq1xiaOI9T0NEdJs7/zM4wY0vzi+Nxs lFvkzguocdtI61XGNx8NprtVsx6VqlXuE+JbrFpckObeDF/QsdSHE0Rmt23gn9/83S9NN gydLzyfJ8u/NgY54dWSW9Djv6JUWf9goqBnmRhvUi4xG3LYrW6AajOz/WcUgKbaVTBy9e 8CQuuQxw8P9s6wzz0pjxfH6wFrCidRgrAb6bAatudrREgu4kVJa/87DXWdDjoz3H7/Q7S ch+LvFFbbVODqSFQbBl0mAbqsrJduQkZkQvYjA02YLWRzywxq3RNplYMSHZWmMZC//Q== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b="jvbky/YE"; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 43529606A31C for ; Fri, 30 Oct 2026 04:54:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=jvbky/YE Received: by smtp.kernel.org (Postfix) with ESMTPSA id 975541F00A02; Fri, 30 Oct 2026 04:54:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793336080; bh=WZfFeDqbdcOih6qA1/0BBGjlPc+vzdZ9HbJkxb4c1zo=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=jvbky/YENJDroiuh3eoYVE6o4UkZNl9WmJIynh5ZBQYmFmDZQ/TQG+rGjlCrHqi0D 3tbIho+rSyF2TKXfCJUqdbZfEa1ga3honDWvn2raXsxejD9BvPTAj146wzOKyG7Fo5 xL7NoaEqjlC2L9NmBrNHdBjF0ueL5YMqFcG62OIOfnRoyLrFqLh3qcjMEnHqm97oIP /ttFgYSQURY02gPbxh2TFPWHgFJ7+XKEym7MrF91FkaGUFDeO8sQ6iGQL3PdpENk3T iGgCZ1kYWaKSmsVrzuEOj8CMNwvjXolzSu7jgdE5phG2HHUC9pzZFBGjOJuTSu56Fd jPn+wgLTvqQuw== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH net v2 2/2] net/iucv: do not count the SHT frame against the receive window Reply-To: sashiko-reviews@lists.linux.dev To: "Bryam Vargas" Cc: linux-s390@vger.kernel.org, "Heiko Carstens" , "Vasily Gorbik" , "Alexander Gordeev" , "Christian Borntraeger" In-Reply-To: <20261028-b4-disp-dd3e4ebb-v2-2-3747658d59bd@proton.me> References: <20261028-b4-disp-dd3e4ebb-v2-0-3747658d59bd@proton.me> <20261028-b4-disp-dd3e4ebb-v2-2-3747658d59bd@proton.me> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 30 Oct 2026 04:54:40 +0000 X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list > From: Bryam Vargas >=20 > iucv_sock_recvmsg() counts every HiperSockets frame it consumes in > msg_recv, the SHT's empty one included, while the peer counts only what > sendmsg() sends against the window it was granted; the SHT goes out > through iucv_send_ctrl() uncounted, one per shutdown(SHUT_WR) call. The > next window update zeroes msg_recv and takes the surplus with it, but > recvmsg() sends none while frames wait in backlog_skb_q, and an SHT read > in that state pushes msg_recv past msglimit: WARN_ON(1) fires, the socket > is closed and the reader gets -EFAULT instead of EOF. A peer that sends > past its window reaches the same WARN from the network; with > panic_on_warn that is a remote panic. The SHT frame dates from > 82492a355fac, the WARN and the close from 800c5eb7b5eb. >=20 > The SHT reaches recvmsg() as a zero-length frame, like a zero-length > [ ... ] > Fixes: 800c5eb7b5eb ("af_iucv: change net_device handling for HS transpor= t") > Reported-by: Sashiko > Closes: https://lore.kernel.org/netdev/179183431327.434549.44634814883785= 0426@kernel.org/ > Cc: stable@vger.kernel.org > Signed-off-by: Bryam Vargas Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261028-b4-disp-dd= 3e4ebb-v2-0-3747658d59bd@proton.me?part=3D2