[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 Signed-off-by: Patrick McHardy --- commit 97ca02fbb25efc9d5410439d9835e4aa7f61a12f tree d0abdcb0dbc76c4b99662fd093afb75288ea6974 parent 42a46c74c4520174b82a60ac44c15b5525cdf238 author Patrick McHardy Tue, 02 May 2006 19:45:49 +0200 committer Patrick McHardy Tue, 02 May 2006 19:45:49 +0200 net/ipv4/netfilter/ip_conntrack_proto_sctp.c | 11 +++++++---- net/netfilter/nf_conntrack_proto_sctp.c | 11 +++++++---- 2 files changed, 14 insertions(+), 8 deletions(-) diff --git a/net/ipv4/netfilter/ip_conntrack_proto_sctp.c b/net/ipv4/netfilter/ip_conntrack_proto_sctp.c index be602e8..ea5cc51 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_con 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 cf798e6..6c3881b 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_con 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; }