From: Patrick McHardy Date: Tue, 2 May 2006 21:23:07 +0000 (+0200) Subject: [NETFILTER] SCTP conntrack: fix infinite loop X-Git-Tag: v2.6.17-rc4~54 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=e17df688f7064dae1417ce425dd1e4b71d24d63b;p=linux-2.6-omap-h63xx.git [NETFILTER] SCTP conntrack: fix infinite loop fix infinite loop in the SCTP-netfilter code: check SCTP chunk size to guarantee progress of for_each_sctp_chunk(). (all other uses of for_each_sctp_chunk() are preceded by do_basic_checks(), so this fix should be complete.) Based on patch from Ingo Molnar CVE-2006-1527 Signed-off-by: Patrick McHardy Signed-off-by: Linus Torvalds --- diff --git a/net/ipv4/netfilter/ip_conntrack_proto_sctp.c b/net/ipv4/netfilter/ip_conntrack_proto_sctp.c index 5259abd0fb4..0416073c560 100644 --- a/net/ipv4/netfilter/ip_conntrack_proto_sctp.c +++ b/net/ipv4/netfilter/ip_conntrack_proto_sctp.c @@ -235,12 +235,15 @@ static int do_basic_checks(struct ip_conntrack *conntrack, flag = 1; } - /* Cookie Ack/Echo chunks not the first OR - Init / Init Ack / Shutdown compl chunks not the only chunks */ - if ((sch->type == SCTP_CID_COOKIE_ACK + /* + * Cookie Ack/Echo chunks not the first OR + * Init / Init Ack / Shutdown compl chunks not the only chunks + * OR zero-length. + */ + if (((sch->type == SCTP_CID_COOKIE_ACK || sch->type == SCTP_CID_COOKIE_ECHO || flag) - && count !=0 ) { + && count !=0) || !sch->length) { DEBUGP("Basic checks failed\n"); return 1; } diff --git a/net/netfilter/nf_conntrack_proto_sctp.c b/net/netfilter/nf_conntrack_proto_sctp.c index 9cccc325b68..0c6da496cfa 100644 --- a/net/netfilter/nf_conntrack_proto_sctp.c +++ b/net/netfilter/nf_conntrack_proto_sctp.c @@ -240,12 +240,15 @@ static int do_basic_checks(struct nf_conn *conntrack, flag = 1; } - /* Cookie Ack/Echo chunks not the first OR - Init / Init Ack / Shutdown compl chunks not the only chunks */ - if ((sch->type == SCTP_CID_COOKIE_ACK + /* + * Cookie Ack/Echo chunks not the first OR + * Init / Init Ack / Shutdown compl chunks not the only chunks + * OR zero-length. + */ + if (((sch->type == SCTP_CID_COOKIE_ACK || sch->type == SCTP_CID_COOKIE_ECHO || flag) - && count !=0 ) { + && count !=0) || !sch->length) { DEBUGP("Basic checks failed\n"); return 1; }