From b1871fd48efc567650dbdc974e5a2342a03fe0d2 Mon Sep 17 00:00:00 2001 From: Karsten Graul Date: Fri, 8 Apr 2022 17:10:33 +0200 Subject: net/smc: use memcpy instead of snprintf to avoid out of bounds read Using snprintf() to convert not null-terminated strings to null terminated strings may cause out of bounds read in the source string. Therefore use memcpy() and terminate the target string with a null afterwards. Fixes: fa0866625543 ("net/smc: add support for user defined EIDs") Fixes: 3c572145c24e ("net/smc: add generic netlink support for system EID") Signed-off-by: Karsten Graul Signed-off-by: Jakub Kicinski --- net/smc/smc_clc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'net/smc') diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c index ce27399b38b1..f9f3f59c79de 100644 --- a/net/smc/smc_clc.c +++ b/net/smc/smc_clc.c @@ -191,7 +191,8 @@ static int smc_nl_ueid_dumpinfo(struct sk_buff *skb, u32 portid, u32 seq, flags, SMC_NETLINK_DUMP_UEID); if (!hdr) return -ENOMEM; - snprintf(ueid_str, sizeof(ueid_str), "%s", ueid); + memcpy(ueid_str, ueid, SMC_MAX_EID_LEN); + ueid_str[SMC_MAX_EID_LEN] = 0; if (nla_put_string(skb, SMC_NLA_EID_TABLE_ENTRY, ueid_str)) { genlmsg_cancel(skb, hdr); return -EMSGSIZE; @@ -252,7 +253,8 @@ int smc_nl_dump_seid(struct sk_buff *skb, struct netlink_callback *cb) goto end; smc_ism_get_system_eid(&seid); - snprintf(seid_str, sizeof(seid_str), "%s", seid); + memcpy(seid_str, seid, SMC_MAX_EID_LEN); + seid_str[SMC_MAX_EID_LEN] = 0; if (nla_put_string(skb, SMC_NLA_SEID_ENTRY, seid_str)) goto err; read_lock(&smc_clc_eid_table.lock); -- cgit v1.2.3 From d22f4f977236f97e01255a80bca2ea93a8094fc8 Mon Sep 17 00:00:00 2001 From: Karsten Graul Date: Fri, 8 Apr 2022 17:10:34 +0200 Subject: net/smc: Fix NULL pointer dereference in smc_pnet_find_ib() dev_name() was called with dev.parent as argument but without to NULL-check it before. Solve this by checking the pointer before the call to dev_name(). Fixes: af5f60c7e3d5 ("net/smc: allow PCI IDs as ib device names in the pnet table") Reported-by: syzbot+03e3e228510223dabd34@syzkaller.appspotmail.com Signed-off-by: Karsten Graul Signed-off-by: Jakub Kicinski --- net/smc/smc_pnet.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'net/smc') diff --git a/net/smc/smc_pnet.c b/net/smc/smc_pnet.c index 7984f8883472..7055ed10e316 100644 --- a/net/smc/smc_pnet.c +++ b/net/smc/smc_pnet.c @@ -311,8 +311,9 @@ static struct smc_ib_device *smc_pnet_find_ib(char *ib_name) list_for_each_entry(ibdev, &smc_ib_devices.list, list) { if (!strncmp(ibdev->ibdev->name, ib_name, sizeof(ibdev->ibdev->name)) || - !strncmp(dev_name(ibdev->ibdev->dev.parent), ib_name, - IB_DEVICE_NAME_MAX - 1)) { + (ibdev->ibdev->dev.parent && + !strncmp(dev_name(ibdev->ibdev->dev.parent), ib_name, + IB_DEVICE_NAME_MAX - 1))) { goto out; } } -- cgit v1.2.3 From 49b7d376abe54a49e8bd5e64824032b7c97c62d4 Mon Sep 17 00:00:00 2001 From: Karsten Graul Date: Fri, 8 Apr 2022 17:10:35 +0200 Subject: net/smc: Fix af_ops of child socket pointing to released memory 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 Signed-off-by: Karsten Graul Reviewed-by: D. Wythe Signed-off-by: Jakub Kicinski --- net/smc/af_smc.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'net/smc') diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index f0d118e9f155..14ddc40149e8 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -121,6 +121,7 @@ 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); @@ -134,8 +135,17 @@ 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); -- cgit v1.2.3