From: Zhao Zhang <zzhan461@ucr.edu> stable inclusion from stable-v5.10.259 commit 6657af827e21883ae90693e42e7f59a6aab690b5 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/15622 CVE: CVE-2026-52917 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 5eba3e48d78edd7551b992cb7ba687019b3a78da upstream. The SCTP exact sock_diag lookup can hold a transport reference, block on lock_sock(sk), and then resume after sctp_association_free() has marked the association dead and freed its bind address list. When that happens, inet_assoc_attr_size() and inet_diag_msg_sctpasoc_fill() can still dereference association state that is no longer valid for reporting. In particular, inet_diag_msg_sctpasoc_fill() may read an empty bind-address list as a real sctp_sockaddr_entry and trigger an out-of-bounds read from unrelated association memory. Reject the association after taking the socket lock if it has been reaped or detached from the endpoint, and report the lookup as stale. This keeps the exact dump-one path from formatting torn association state. Fixes: 8f840e47f190 ("sctp: add the sctp_diag.c file") Cc: stable@kernel.org Reported-by: Yuan Tan <yuantan098@gmail.com> Reported-by: Yifan Wu <yifanwucs@gmail.com> Reported-by: Juefei Pu <tomapufckgml@gmail.com> Reported-by: Zhengchuan Liang <zcliangcn@gmail.com> Reported-by: Xin Liu <bird@lzu.edu.cn> Signed-off-by: Zhao Zhang <zzhan461@ucr.edu> Signed-off-by: Ren Wei <n05ec@lzu.edu.cn> Acked-by: Xin Long <lucien.xin@gmail.com> Link: https://patch.msgid.link/fac6043fa20a2ff68e12958c431836f692c51268.1780113823... Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Ze Zuo <zuoze1@huawei.com> --- net/sctp/diag.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/net/sctp/diag.c b/net/sctp/diag.c index 6ae474c9466b..c427e5e9e8f3 100644 --- a/net/sctp/diag.c +++ b/net/sctp/diag.c @@ -259,15 +259,15 @@ static int sctp_sock_dump_one(struct sctp_endpoint *ep, struct sctp_transport *t lock_sock(sk); - rep = nlmsg_new(inet_assoc_attr_size(sk, assoc), GFP_KERNEL); - if (!rep) { - release_sock(sk); - return -ENOMEM; + if (ep != assoc->ep || assoc->base.dead) { + err = -ESTALE; + goto out_unlock; } - if (ep != assoc->ep) { - err = -EAGAIN; - goto out; + rep = nlmsg_new(inet_assoc_attr_size(sk, assoc), GFP_KERNEL); + if (!rep) { + err = -ENOMEM; + goto out_unlock; } err = inet_sctp_diag_fill(sk, assoc, rep, req, sk_user_ns(NETLINK_CB(skb).sk), @@ -282,8 +282,9 @@ static int sctp_sock_dump_one(struct sctp_endpoint *ep, struct sctp_transport *t return nlmsg_unicast(sock_net(skb->sk)->diag_nlsk, rep, NETLINK_CB(skb).portid); out: - release_sock(sk); kfree_skb(rep); +out_unlock: + release_sock(sk); return err; } -- 2.25.1