From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-io1-f69.google.com (mail-io1-f69.google.com [209.85.166.69]) (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 ED2981A3142 for ; Sat, 5 Jul 2025 09:27:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.69 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751707670; cv=none; b=mZQtGDCDOhLD4+YyjvMPCyIaIJw5BGuDV3JhPIj7bNAvfgXALV/jiRYV4fUIZK56r/F4GJjnn4i9cF81NI0IlbdNNcdrv/iGUffqfioNJuBHgZv5BgoaGwnwey8sy+IgEz8SOEDX9YWZ5QUobjL3ynvHlbaE7nAOkYGJ5LkjgSs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751707670; c=relaxed/simple; bh=+S677AhOefcSqJs5yrwnv1yg868QHmWn7NVnUUe7H+Q=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To:Cc: Content-Type; b=BSq8LJQIZaAXx5c3PZ4KBllxjX/j5nOPxc1DljqY4DRSj/ZBpDDZQ9f4K23PlynLXo9Z2zqBgj2d5lw2g9SqXU7W9+2JWBqaJjE+WKH0jO7p5kAybq7RFpxKeVx8qiXZDemtKmAtbW5bI/qWyQ2N0mKUDabx+PyqTZ+HcyW3iic= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.166.69 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-io1-f69.google.com with SMTP id ca18e2360f4ac-86cf0364dd2so278352639f.0 for ; Sat, 05 Jul 2025 02:27:48 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1751707668; x=1752312468; h=cc:to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=+fY3a8I8+COUPqjAARrlRnUdwmTXHzUtWTquSqGNZ9U=; b=cEpufD019+nY58LRdNZ5BPumk2M3uMsMIlFwsulVeDK96SeBednlQDnAYu1qb0XZhb +ZUW3hAN8o673caGosbZlySvBQy6hJg9t3r58paz6NvRiqmHyIWpxL5FzjoqLw1iIR4B WiLR5h22XCte1EI6wb40jwLVoJZCc+I430y1hsxYvbl0JWj6j/SDun6CRWKsUjyfvddK m9AVrtV8kDWaDN4Uioh1lpNqwzrGtiGgU5RDaGG1p0ECwLLGdjA1p7O6jljcPnVaou+1 Pdk9cnR6LDXUZFvB4+XNbOoXKodVPKOkCyzQW09OtlPa6hv9I5/geNwn9fjAZAZ7KfnK biAg== X-Gm-Message-State: AOJu0YxqVHl1D817sZqrk6V3i/k5sQZdPWS2JPk2AR58JFBbaKBCOaaF 5B+rsozt8Ofurm5+XknZhVRSKEz23MIGYQd71+W7Wo/yQVePZwRJprxYOS7qwaJPCIZOygNovOp mms5GClGyvJQvbUD+PyKlCv54YXCQHW+vnbPMuB4SNCf8n1xTuLr+s9aEgmI= X-Google-Smtp-Source: AGHT+IHWWa5WzcHB8KtthAt0+HcVoZkbbdMoupQ3aDOeAtPXRH649h9x7ObZMyubVG6MqVxkVmvBBiytYcd+n6949l0BoKFYWNc6 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:1d86:b0:3dd:b808:be68 with SMTP id e9e14a558f8ab-3e13ef146f7mr14083045ab.16.1751707668129; Sat, 05 Jul 2025 02:27:48 -0700 (PDT) Date: Sat, 05 Jul 2025 02:27:48 -0700 In-Reply-To: <20250705092739.28018-1-takamitz@amazon.co.jp> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6868f014.a00a0220.c7b3.0033.GAE@google.com> Subject: Re: [syzbot] [net?] WARNING in taprio_get_start_time (2) From: syzbot To: takamitz@amazon.co.jp Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, takamitz@amazon.co.jp, takamitz@amazon.com Content-Type: text/plain; charset="UTF-8" > I found validation does not work properly when link speed is large. > picos_per_byte becomes too small when link speed is large, and > length_to_duration(q, ETH_ZLEN) becomes zero. This results in failing > validation in fill_sched_entry() and parse_taprio_schedule(), and any > entry->interval and cycle_time are permitted. > > picos_per_byte should be larger than 16 because ETH_ZLEN (60) * > &q->picos_per_byte should be larger than PSEC_PER_NSEC=1000. > > This report seems to be related this, so let me check the following patch > resolve the issue. > > #syz test This crash does not have a reproducer. I cannot test it. > > diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c > index 2b14c81a87e5..b0a5bd1c9995 100644 > --- a/net/sched/sch_taprio.c > +++ b/net/sched/sch_taprio.c > @@ -43,6 +43,11 @@ static struct static_key_false taprio_have_working_mqprio; > #define TAPRIO_SUPPORTED_FLAGS \ > (TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST | TCA_TAPRIO_ATTR_FLAG_FULL_OFFLOAD) > #define TAPRIO_FLAGS_INVALID U32_MAX > +/* picos_per_byte should be larger than 16 since duration for minimum ethernet > + * frame should not be zero. > + */ > +#define TAPRIO_PICOS_PER_BYTE_MIN 17 > + > > struct sched_entry { > /* Durations between this GCL entry and the GCL entry where the > @@ -1299,7 +1304,7 @@ static void taprio_set_picos_per_byte(struct net_device *dev, > speed = ecmd.base.speed; > > skip: > - picos_per_byte = (USEC_PER_SEC * 8) / speed; > + picos_per_byte = max((USEC_PER_SEC * 8) / speed, TAPRIO_PICOS_PER_BYTE_MIN); > > atomic64_set(&q->picos_per_byte, picos_per_byte); > netdev_dbg(dev, "taprio: set %s's picos_per_byte to: %lld, linkspeed: %d\n",