From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 E588F319614; Fri, 2 Jan 2026 20:04:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767384247; cv=none; b=NEQ1RAg4gJkxG0jOoshQ9lBtPUZDyqTQCT3BTbx7bxaY+iSlNSwre2cSvc40mwu9tDrLECjSS/8IboskKqNe0ZsQNHue1GxP9DQCBlp1OnaguWcAthIXux8Qp0EKhWvhf4maPtwAk0pgTYmIvjILm+7+RY+R2kTIQ/S6ix2+qhE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767384247; c=relaxed/simple; bh=2vq9xeh/ZjwJCXeCtC2pq+VOjFi6w5FQElmEF3VFqI4=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=CxYKCpWtT0yVNSWvL9p8656Gt0UzNMS0iLBJd2x0fsBuBf4At7KC4s2KAqkEDjTeA5nDXwH4nmg8D7pMxlAEE7qqVPtHK3ucWYudgZ5pO/I2Dh+PASrLnfWqFdGWCwQ7hnhcdYpFv+IQXiaBOZ81GwHF/ZPGaR5tzV07o9echGQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LatBHsvD; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LatBHsvD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0D356C116B1; Fri, 2 Jan 2026 20:04:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1767384246; bh=2vq9xeh/ZjwJCXeCtC2pq+VOjFi6w5FQElmEF3VFqI4=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=LatBHsvD91n9PNyXgiGK0woU+gfEz/RmcTMpAH63pH2HJ45jAmGWuxu0/CWc6nRyi d5iMxlym4KCsdn7VB+gsCe6IlDZfYidTTJkIFws+m+X8TDdooFeYDU46F2mQTLq16I D7dz7PAfigSVVC0otmNZFVr8AXNNcKNnk4dle1D13AEqFGsSgxqNJpalYuDQ7tEsB0 +Ej+i+szISTz0FYqKX3mQvRdi26UPAQv00iyWhyOIE67wYMNE2BCEbKZAefNsfEifk v4M3YBamRKzulRg+iPuvjzlCQdXEyfoMvPPEJZUc36e4U6wxwUnfRyS0SbUo950kQj CEwhk5RS94Fzw== Date: Fri, 2 Jan 2026 12:04:05 -0800 From: Jakub Kicinski To: Prithvi Cc: andrii@kernel.org, socketcan@hartkopp.net, mkl@pengutronix.de, linux-can@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, netdev@vger.kernel.org Subject: Re: [bpf, xdp] headroom - was: Re: Question about to KMSAN: uninit-value in can_receive Message-ID: <20260102120405.34613b68@kernel.org> In-Reply-To: <20260102153611.63wipdy2meh3ovel@inspiron> References: <20251117173012.230731-1-activprithvi@gmail.com> <0c98b1c4-3975-4bf5-9049-9d7f10d22a6d@hartkopp.net> <20251220173338.w7n3n4lkvxwaq6ae@inspiron> <01190c40-d348-4521-a2ab-3e9139cc832e@hartkopp.net> <20260102153611.63wipdy2meh3ovel@inspiron> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Fri, 2 Jan 2026 21:06:11 +0530 Prithvi wrote: > Just a gentle ping on this thread You're asking the wrong person, IIUC Andrii is tangentially involved in XDP (via bpf links?): XDP (eXpress Data Path) M: Alexei Starovoitov M: Daniel Borkmann M: David S. Miller M: Jakub Kicinski M: Jesper Dangaard Brouer M: John Fastabend R: Stanislav Fomichev L: netdev@vger.kernel.org L: bpf@vger.kernel.org Without looking too deeply - XDP has historically left the new space uninitialized after push, expecting programs to immediately write the headers in that space. syzbot had run into this in the past but I can't find any references to past threads quickly :(