Date: Wed, 6 Jun 2018 20:00:22 +0000 (UTC) From: Michael Tuexen <tuexen@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-11@freebsd.org Subject: svn commit: r334730 - stable/11/sys/netinet Message-ID: <201806062000.w56K0MaR006463@repo.freebsd.org>
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Author: tuexen Date: Wed Jun 6 20:00:21 2018 New Revision: 334730 URL: https://svnweb.freebsd.org/changeset/base/334730 Log: MFC r334494: Ensure net.inet.tcp.syncache.rexmtlimit is limited by TCP_MAXRXTSHIFT. If the sysctl variable is set to a value larger than TCP_MAXRXTSHIFT+1, the array tcp_syn_backoff[] is accessed out of bounds. Discussed with: jtl@ Sponsored by: Netflix, Inc. Modified: stable/11/sys/netinet/tcp_syncache.c Directory Properties: stable/11/ (props changed) Modified: stable/11/sys/netinet/tcp_syncache.c ============================================================================== --- stable/11/sys/netinet/tcp_syncache.c Wed Jun 6 19:56:19 2018 (r334729) +++ stable/11/sys/netinet/tcp_syncache.c Wed Jun 6 20:00:21 2018 (r334730) @@ -175,8 +175,27 @@ SYSCTL_UINT(_net_inet_tcp_syncache, OID_AUTO, hashsize &VNET_NAME(tcp_syncache.hashsize), 0, "Size of TCP syncache hashtable"); -SYSCTL_UINT(_net_inet_tcp_syncache, OID_AUTO, rexmtlimit, CTLFLAG_VNET | CTLFLAG_RW, +static int +sysctl_net_inet_tcp_syncache_rexmtlimit_check(SYSCTL_HANDLER_ARGS) +{ + int error; + u_int new; + + new = V_tcp_syncache.rexmt_limit; + error = sysctl_handle_int(oidp, &new, 0, req); + if ((error == 0) && (req->newptr != NULL)) { + if (new > TCP_MAXRXTSHIFT) + error = EINVAL; + else + V_tcp_syncache.rexmt_limit = new; + } + return (error); +} + +SYSCTL_PROC(_net_inet_tcp_syncache, OID_AUTO, rexmtlimit, + CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, &VNET_NAME(tcp_syncache.rexmt_limit), 0, + sysctl_net_inet_tcp_syncache_rexmtlimit_check, "UI", "Limit on SYN/ACK retransmissions"); VNET_DEFINE(int, tcp_sc_rst_sock_fail) = 1;
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