From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-181.mta1.migadu.com (out-181.mta1.migadu.com [95.215.58.181]) (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 742CA17545 for ; Wed, 17 Jul 2024 19:16:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.181 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721243791; cv=none; b=m6GfZH/Q6MDmamYmrge3OSQkNlcz/pNBXGM19DF9449D8nbBCV6c8lsPpm5M6dDaYAgd6i/VfrSA+qg8yY7fMkff6SmrvMuNoPj10oe7/pQfg+BS73BGs3wetdP8jmSwDV9DIKk/TwgFRCw7osHIVOAIl9j9RNvzNlqqOpxsySY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721243791; c=relaxed/simple; bh=dWEsRQH395VEBrUpm8P8J+4vocY7M+svKcuuXSmZKfM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=GqXObNmXbnSNNUYL/ClL3MJqgJtO/U0pb7YDs6VTOMjV3/Smxk8yBoMU1rOi1nGsFrSN1v6O8x1nNfx7W78oRDYXOfXvJMk3MUiK634xD4qUjXCGUOiQqCP1bbtvkn9uwEiUsHZoqfOr02L7z1H4YNGWD2GbLxuYokuxJlxTVXM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=AJIYf0vC; arc=none smtp.client-ip=95.215.58.181 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="AJIYf0vC" X-Envelope-To: toke@redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1721243786; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=fH5ALR4dDh/EwVo7Sy+L0QyU76WKYRhmEvdApIz7gxM=; b=AJIYf0vCQIqtT+G8toHuUXyxX6UKx63dh2phO8HRTMyABIBm0ElvPqfGN4sacZWt9dfDfq E3JoxXbxz8DaOoCvl8L4yimqmMiwKgj1zVg7glTTqEMaE40eWshNh6DWutqncuMVXZFcXX MMH5Y0vBNbQGyj6g5jvrPl4gpKR0DCU= X-Envelope-To: bpf@vger.kernel.org X-Envelope-To: linux-kernel@vger.kernel.org X-Envelope-To: netdev@vger.kernel.org X-Envelope-To: revest@google.com X-Envelope-To: syzbot+cca39e6e84a367a7e6f6@syzkaller.appspotmail.com X-Envelope-To: alexei.starovoitov@gmail.com X-Envelope-To: michal.switala@infogain.com Message-ID: Date: Wed, 17 Jul 2024 12:16:16 -0700 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH] bpf: Ensure BPF programs testing skb context initialization To: =?UTF-8?Q?Toke_H=C3=B8iland-J=C3=B8rgensen?= Cc: bpf@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, revest@google.com, syzbot+cca39e6e84a367a7e6f6@syzkaller.appspotmail.com, alexei.starovoitov@gmail.com, Michal Switala References: <20240715181339.2489649-1-michal.switala@infogain.com> <250854fc-ce22-4866-95f9-d61f6653af64@linux.dev> <87y160407o.fsf@toke.dk> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Martin KaFai Lau In-Reply-To: <87y160407o.fsf@toke.dk> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT On 7/17/24 6:28 AM, Toke Høiland-Jørgensen wrote: >> It looks very similar to >> https://lore.kernel.org/bpf/000000000000f6531b061494e696@google.com/. It has >> been fixed in commit 5bcf0dcbf906 ("xdp: use flags field to disambiguate >> broadcast redirect") >> >> I tried the C repro. I can reproduce in the bpf tree also which should have the >> fix. I cannot reproduce in the bpf-next though. >> >> Cc Toke who knows more details here. > > Hmm, yeah, it does look kinda similar. Do you mean that the C repro from > this new report triggers the crash for you on the current -bpf tree? I was able to repro in bpf tree ~two days ago but not now. The bpf tree has been fast forwarded and has the 6.10 changes. I just tried linux-stable/linux-6.9.y which has the fix in the commit 5bcf0dcbf906. The syzbot report (against the 36534d3c5453) also has that fix. In particular, the syzbot repro I tried: https://syzkaller.appspot.com/text?tag=ReproC&x=17caa30a980000