From nobody Thu Dec 21 04:15:04 2023 X-Original-To: bugs@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4SwcXS6cTLz54G13 for ; Thu, 21 Dec 2023 04:15:04 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4SwcXS5Ytyz4Xfj for ; Thu, 21 Dec 2023 04:15:04 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) ARC-Seal: i=1; s=dkim; d=freebsd.org; t=1703132104; a=rsa-sha256; cv=none; b=UTyksGTRbshu6a826l2+wm+4qRNagw9yFc6tvNTzxLi2iIie+Xl2Y3fk9RTvwD0qY6hn4E OlKQVMEY75FVBKQEbTlnqVY65ITt05kvb0ugpyp3CRBhsmGBZU02paCospR0AsUmvT+kJx 1MY6N4P6cyGhyPXtUohGka55vWqPjgZ4zqkPA7bMbOEMWOvYW37ZYlvri1J70NWEELaXjA Ke6uAs0+SAfGd9DB5jRHHCcyzWCsrEMG5dbgAkqY3vDLQgtMOeHHfWLPQMiI8+cvb77HA5 KmX05xI0ExiiobukQWuaw/b8qJXtl1S+xgAlEJJe1VAeWujhKRRBG5KVfHQ7RA== ARC-Authentication-Results: i=1; mx1.freebsd.org; none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=freebsd.org; s=dkim; t=1703132104; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JflgKDUhYDCyFbQAOZoniPqVoYmX0OY3VJAbDZX9x/I=; b=iwjE8L0PZiRfpyPer7gaJjUZcwKcGF1dPgoZgkv2rhI09+OphrpQS/yQDv5tK1rIMGuYEv gUXMOXTKaOfVMyfY4LkAEzT+P+bpyljvbygIH1Wb0YahZWfj+wcgJWHnysz8fxNJMXmnK4 AFi5Id5p70x23B069RtuFn6rFGV4BkAIth+VstjglEgkdkii794w1Ky+F8Du5faK3yl9tH WWCFJLNGDNTidAHygA4qnbhm864KHJ/kcPvzKU2JdfkEKQ5aUw5VX4UiyrtwJmeYRgU8c3 F9yvKWMfAXlDOrmog8K0uLw1LdQS8s3YFN1F1w/QYMX3ZJ77rB8Rf00midpevA== Received: from kenobi.freebsd.org (kenobi.freebsd.org [IPv6:2610:1c1:1:606c::50:1d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 4SwcXS4Vxgz38M for ; Thu, 21 Dec 2023 04:15:04 +0000 (UTC) (envelope-from bugzilla-noreply@freebsd.org) Received: from kenobi.freebsd.org ([127.0.1.5]) by kenobi.freebsd.org (8.15.2/8.15.2) with ESMTP id 3BL4F4Pr074872 for ; Thu, 21 Dec 2023 04:15:04 GMT (envelope-from bugzilla-noreply@freebsd.org) Received: (from www@localhost) by kenobi.freebsd.org (8.15.2/8.15.2/Submit) id 3BL4F4XL074871 for bugs@FreeBSD.org; Thu, 21 Dec 2023 04:15:04 GMT (envelope-from bugzilla-noreply@freebsd.org) X-Authentication-Warning: kenobi.freebsd.org: www set sender to bugzilla-noreply@freebsd.org using -f From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 272965] 14.0-ALPHA1 too: armv7 'Alignment Fault' on read panic during udp_input for kyua's sys/netinet6/exthdr:exthdr ; other udp_input related panics Date: Thu, 21 Dec 2023 04:15:04 +0000 X-Bugzilla-Reason: AssignedTo X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: Base System X-Bugzilla-Component: kern X-Bugzilla-Version: CURRENT X-Bugzilla-Keywords: X-Bugzilla-Severity: Affects Some People X-Bugzilla-Who: mmel@FreeBSD.org X-Bugzilla-Status: New X-Bugzilla-Resolution: X-Bugzilla-Priority: --- X-Bugzilla-Assigned-To: bugs@FreeBSD.org X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: https://bugs.freebsd.org/bugzilla/ Auto-Submitted: auto-generated List-Id: Bug reports List-Archive: https://lists.freebsd.org/archives/freebsd-bugs List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-bugs@freebsd.org MIME-Version: 1.0 https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=3D272965 --- Comment #10 from Michal Meloun --- (In reply to Warner Losh from comment #8) Unfortunately, I can't agree with that. Aligning the input mbuf is only papering over the real problem and can only work for trivial cases. It doe= sn't help for vlans (unless HW strips header), for various protocol encapsulatio= ns and most importantly it doesn't work at all for IPv6 :( The real problem is that our network stack uses undefined behavior. We can alias a byte buffer to a structure only if the given buffer pointer is conf= orm with the desired structure alignment, otherwise the behavior is undefined. = This is, strictly speaking , required for every architecture. The only way we can reduce the required alignment is by using the packed attribute for the affe= cted structures... --=20 You are receiving this mail because: You are the assignee for the bug.=