This is a note to let you know that I've just added the patch titled sctp: use the correct skb for security_sctp_assoc_request to the 5.17-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: sctp-use-the-correct-skb-for-security_sctp_assoc_req.patch and it can be found in the queue-5.17 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 2d128bd144a7b26fb8cca7c6f894bc7e140c39fe Author: Xin Long <lucien.xin@xxxxxxxxx> Date: Thu Apr 7 09:24:22 2022 -0400 sctp: use the correct skb for security_sctp_assoc_request [ Upstream commit e2d88f9ce678cd33763826ae2f0412f181251314 ] 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. v1->v2: - As Ondrej noticed, chunk->head_skb should also be used for security_sctp_assoc_established() in sctp_sf_do_5_1E_ca(). 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> Reviewed-by: Ondrej Mosnacek <omosnace@xxxxxxxxxx> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx> Link: https://lore.kernel.org/r/71becb489e51284edf0c11fc15246f4ed4cef5b6.1649337862.git.lucien.xin@xxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c index 7f342bc12735..52edee1322fc 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); } @@ -932,7 +932,7 @@ enum sctp_disposition sctp_sf_do_5_1E_ca(struct net *net, /* Set peer label for connection. */ if (security_sctp_assoc_established((struct sctp_association *)asoc, - chunk->skb)) + chunk->head_skb ?: chunk->skb)) return sctp_sf_pdiscard(net, ep, asoc, type, arg, commands); /* Verify that the chunk length for the COOKIE-ACK is OK. @@ -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); }