From owner-dev-commits-src-all@freebsd.org Sat Jul 10 11:13:05 2021 Return-Path: Delivered-To: dev-commits-src-all@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id BF4E46528B4; Sat, 10 Jul 2021 11:13:05 +0000 (UTC) (envelope-from git@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 4GMS7P50bVz4hHx; Sat, 10 Jul 2021 11:13:05 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org (gitrepo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:5]) (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 9473126E31; Sat, 10 Jul 2021 11:13:05 +0000 (UTC) (envelope-from git@FreeBSD.org) Received: from gitrepo.freebsd.org ([127.0.1.44]) by gitrepo.freebsd.org (8.16.1/8.16.1) with ESMTP id 16ABD5wo009027; Sat, 10 Jul 2021 11:13:05 GMT (envelope-from git@gitrepo.freebsd.org) Received: (from git@localhost) by gitrepo.freebsd.org (8.16.1/8.16.1/Submit) id 16ABD5dG009026; Sat, 10 Jul 2021 11:13:05 GMT (envelope-from git) Date: Sat, 10 Jul 2021 11:13:05 GMT Message-Id: <202107101113.16ABD5dG009026@gitrepo.freebsd.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org From: =?utf-8?Q?Stefan E=C3=9Fer?= Subject: git: 58080fbca09f - main - libalias: fix divide by zero causing panic MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit X-Git-Committer: se X-Git-Repository: src X-Git-Refname: refs/heads/main X-Git-Reftype: branch X-Git-Commit: 58080fbca09fda6d5f011d37059edbca8ceb4c58 Auto-Submitted: auto-generated X-BeenThere: dev-commits-src-all@freebsd.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Commit messages for all branches of the src repository List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 10 Jul 2021 11:13:05 -0000 The branch main has been updated by se: URL: https://cgit.FreeBSD.org/src/commit/?id=58080fbca09fda6d5f011d37059edbca8ceb4c58 commit 58080fbca09fda6d5f011d37059edbca8ceb4c58 Author: Stefan Eßer AuthorDate: 2021-07-10 11:00:56 +0000 Commit: Stefan Eßer CommitDate: 2021-07-10 11:08:18 +0000 libalias: fix divide by zero causing panic The packet_limit can fall to 0, leading to a divide by zero abort in the "packets % packet_limit". An possible solution would be to apply a lower limit of 1 after the calculation of packet_limit, but since any number modulo 1 gives 0, the more efficient solution is to skip the modulo operation for packet_limit <= 1. Since this is a fix for a panic observed in stable/12, merging this fix to stable/12 and stable/13 before expiry of the 3 day waiting period might be justified, if it works for the reporter of the issue. Reported by: Karl Denninger MFC after: 3 days --- sys/netinet/libalias/alias_db.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sys/netinet/libalias/alias_db.c b/sys/netinet/libalias/alias_db.c index c09ad4352ce4..4612b32c139c 100644 --- a/sys/netinet/libalias/alias_db.c +++ b/sys/netinet/libalias/alias_db.c @@ -1769,7 +1769,7 @@ HouseKeeping(struct libalias *la) * Reduce the amount of house keeping work substantially by * sampling over the packets. */ - if (packets % packet_limit == 0) { + if (packet_limit <= 1 || packets % packet_limit == 0) { time_t now; #ifdef _KERNEL