Yi Chen reported an unexpected sctp connection abort, and it occurred when COOKIE_ECHO is bundled with DATA Fragment by SCTP HW GSO. As the IP header is included in chunk->head_skb instead of chunk->skb, it failed to check IP header version in security_sctp_assoc_request(). According to Ondrej, SELinux only looks at IP header (address and IPsec options) and XFRM state data, and these are all included in head_skb for SCTP HW GSO packets. So fix it by using head_skb when calling security_sctp_assoc_request() in processing COOKIE_ECHO. Fixes: e215dab1c490 ("security: call security_sctp_assoc_request in sctp_sf_do_5_1D_ce") Reported-by: Yi Chen <yiche@xxxxxxxxxx> Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx> --- net/sctp/sm_statefuns.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c index 7f342bc12735..883f9b849ee5 100644 --- a/net/sctp/sm_statefuns.c +++ b/net/sctp/sm_statefuns.c @@ -781,7 +781,7 @@ enum sctp_disposition sctp_sf_do_5_1D_ce(struct net *net, } } - if (security_sctp_assoc_request(new_asoc, chunk->skb)) { + if (security_sctp_assoc_request(new_asoc, chunk->head_skb ?: chunk->skb)) { sctp_association_free(new_asoc); return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); } @@ -2262,7 +2262,7 @@ enum sctp_disposition sctp_sf_do_5_2_4_dupcook( } /* Update socket peer label if first association. */ - if (security_sctp_assoc_request(new_asoc, chunk->skb)) { + if (security_sctp_assoc_request(new_asoc, chunk->head_skb ?: chunk->skb)) { sctp_association_free(new_asoc); return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); } -- 2.31.1