From 8a4465368964b4fbaf084760c94c7aabf61059fb Mon Sep 17 00:00:00 2001 From: Guvenc Gulce Date: Tue, 12 Jan 2021 17:21:22 +0100 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: a3db10efcc4c ("net/smc: Add support for obtaining SMCR device list") Signed-off-by: Guvenc Gulce Signed-off-by: Karsten Graul Signed-off-by: Jakub Kicinski --- net/smc/smc_core.c | 17 +++++++++++------ net/smc/smc_ib.c | 6 +++--- net/smc/smc_ism.c | 3 ++- 3 files changed, 16 insertions(+), 10 deletions(-) (limited to 'net') diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index 8d866b4ed8f6..0df85a12651e 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -258,7 +258,8 @@ int smc_nl_get_sys_info(struct sk_buff *skb, struct netlink_callback *cb) smc_ism_get_system_eid(smcd_dev, &seid); mutex_unlock(&smcd_dev_list.mutex); if (seid && smc_ism_is_v2_capable()) { - snprintf(smc_seid, sizeof(smc_seid), "%s", seid); + memcpy(smc_seid, seid, SMC_MAX_EID_LEN); + smc_seid[SMC_MAX_EID_LEN] = 0; if (nla_put_string(skb, SMC_NLA_SYS_SEID, smc_seid)) goto errattr; } @@ -296,7 +297,8 @@ static int smc_nl_fill_lgr(struct smc_link_group *lgr, goto errattr; if (nla_put_u8(skb, SMC_NLA_LGR_R_VLAN_ID, lgr->vlan_id)) goto errattr; - snprintf(smc_target, sizeof(smc_target), "%s", lgr->pnet_id); + memcpy(smc_target, lgr->pnet_id, SMC_MAX_PNETID_LEN); + smc_target[SMC_MAX_PNETID_LEN] = 0; if (nla_put_string(skb, SMC_NLA_LGR_R_PNETID, smc_target)) goto errattr; @@ -313,7 +315,7 @@ static int smc_nl_fill_lgr_link(struct smc_link_group *lgr, struct sk_buff *skb, struct netlink_callback *cb) { - char smc_ibname[IB_DEVICE_NAME_MAX + 1]; + char smc_ibname[IB_DEVICE_NAME_MAX]; u8 smc_gid_target[41]; struct nlattr *attrs; u32 link_uid = 0; @@ -462,7 +464,8 @@ static int smc_nl_fill_smcd_lgr(struct smc_link_group *lgr, goto errattr; if (nla_put_u32(skb, SMC_NLA_LGR_D_CHID, smc_ism_get_chid(lgr->smcd))) goto errattr; - snprintf(smc_pnet, sizeof(smc_pnet), "%s", lgr->smcd->pnetid); + memcpy(smc_pnet, lgr->smcd->pnetid, SMC_MAX_PNETID_LEN); + smc_pnet[SMC_MAX_PNETID_LEN] = 0; if (nla_put_string(skb, SMC_NLA_LGR_D_PNETID, smc_pnet)) goto errattr; @@ -475,10 +478,12 @@ static int smc_nl_fill_smcd_lgr(struct smc_link_group *lgr, goto errv2attr; if (nla_put_u8(skb, SMC_NLA_LGR_V2_OS, lgr->peer_os)) goto errv2attr; - snprintf(smc_host, sizeof(smc_host), "%s", lgr->peer_hostname); + memcpy(smc_host, lgr->peer_hostname, SMC_MAX_HOSTNAME_LEN); + smc_host[SMC_MAX_HOSTNAME_LEN] = 0; if (nla_put_string(skb, SMC_NLA_LGR_V2_PEER_HOST, smc_host)) goto errv2attr; - snprintf(smc_eid, sizeof(smc_eid), "%s", lgr->negotiated_eid); + memcpy(smc_eid, lgr->negotiated_eid, SMC_MAX_EID_LEN); + smc_eid[SMC_MAX_EID_LEN] = 0; if (nla_put_string(skb, SMC_NLA_LGR_V2_NEG_EID, smc_eid)) goto errv2attr; diff --git a/net/smc/smc_ib.c b/net/smc/smc_ib.c index ddd7fac98b1d..7d7ba0320d5a 100644 --- a/net/smc/smc_ib.c +++ b/net/smc/smc_ib.c @@ -371,8 +371,8 @@ static int smc_nl_handle_dev_port(struct sk_buff *skb, if (nla_put_u8(skb, SMC_NLA_DEV_PORT_PNET_USR, smcibdev->pnetid_by_user[port])) goto errattr; - snprintf(smc_pnet, sizeof(smc_pnet), "%s", - (char *)&smcibdev->pnetid[port]); + memcpy(smc_pnet, &smcibdev->pnetid[port], SMC_MAX_PNETID_LEN); + smc_pnet[SMC_MAX_PNETID_LEN] = 0; if (nla_put_string(skb, SMC_NLA_DEV_PORT_PNETID, smc_pnet)) goto errattr; if (nla_put_u32(skb, SMC_NLA_DEV_PORT_NETDEV, @@ -414,7 +414,7 @@ static int smc_nl_handle_smcr_dev(struct smc_ib_device *smcibdev, struct sk_buff *skb, struct netlink_callback *cb) { - char smc_ibname[IB_DEVICE_NAME_MAX + 1]; + char smc_ibname[IB_DEVICE_NAME_MAX]; struct smc_pci_dev smc_pci_dev; struct pci_dev *pci_dev; unsigned char is_crit; diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c index 524ef64a191a..9c6e95882553 100644 --- a/net/smc/smc_ism.c +++ b/net/smc/smc_ism.c @@ -250,7 +250,8 @@ static int smc_nl_handle_smcd_dev(struct smcd_dev *smcd, goto errattr; if (nla_put_u8(skb, SMC_NLA_DEV_PORT_PNET_USR, smcd->pnetid_by_user)) goto errportattr; - snprintf(smc_pnet, sizeof(smc_pnet), "%s", smcd->pnetid); + memcpy(smc_pnet, smcd->pnetid, SMC_MAX_PNETID_LEN); + smc_pnet[SMC_MAX_PNETID_LEN] = 0; if (nla_put_string(skb, SMC_NLA_DEV_PORT_PNETID, smc_pnet)) goto errportattr; -- cgit v1.2.3-70-g09d2