From: Karsten Graul <kgraul@linux.ibm.com> mainline inclusion from mainline-v5.18-rc3 commit 49b7d376abe54a49e8bd5e64824032b7c97c62d4 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IC914B Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Child sockets may inherit the af_ops from the parent listen socket. When the listen socket is released then the af_ops of the child socket points to released memory. Solve that by restoring the original af_ops for child sockets which inherited the parent af_ops. And clear any inherited user_data of the parent socket. Fixes: 8270d9c21041 ("net/smc: Limit backlog connections") Reviewed-by: Wenjia Zhang <wenjia@linux.ibm.com> Signed-off-by: Karsten Graul <kgraul@linux.ibm.com> Reviewed-by: D. Wythe <alibuda@linux.alibaba.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Wang Liang <wangliang74@huawei.com> --- net/smc/af_smc.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index 0f3dd23128b2..cec3e299c9d2 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -81,6 +81,7 @@ static struct sock *smc_tcp_syn_recv_sock(const struct sock *sk, bool *own_req) { struct smc_sock *smc; + struct sock *child; smc = smc_clcsock_user_data(sk); @@ -94,8 +95,17 @@ static struct sock *smc_tcp_syn_recv_sock(const struct sock *sk, } /* passthrough to original syn recv sock fct */ - return smc->ori_af_ops->syn_recv_sock(sk, skb, req, dst, req_unhash, - own_req); + child = smc->ori_af_ops->syn_recv_sock(sk, skb, req, dst, req_unhash, + own_req); + /* child must not inherit smc or its ops */ + if (child) { + rcu_assign_sk_user_data(child, NULL); + + /* v4-mapped sockets don't inherit parent ops. Don't restore. */ + if (inet_csk(child)->icsk_af_ops == inet_csk(sk)->icsk_af_ops) + inet_csk(child)->icsk_af_ops = smc->ori_af_ops; + } + return child; drop: dst_release(dst); -- 2.34.1