When receiving proposal msg in server, the fields v2_ext_offset/
eid_cnt/ism_gid_cnt in proposal msg are from the remote client
and can not be fully trusted. Especially the field v2_ext_offset,
once exceed the max value, there has the chance to access wrong
address, and crash may happen.
This patch checks the fields v2_ext_offset/eid_cnt/ism_gid_cnt
before using them.
Fixes: 8c3dca341aea ("net/smc: build and send V2 CLC proposal")
Signed-off-by: Guangguan Wang <guangguan.wang@xxxxxxxxxxxxxxxxx>
Reviewed-by: Wen Gu <guwen@xxxxxxxxxxxxxxxxx>
Reviewed-by: D. Wythe <alibuda@xxxxxxxxxxxxxxxxx>
---
net/smc/af_smc.c | 3 ++-
net/smc/smc_clc.c | 8 +++++++-
net/smc/smc_clc.h | 8 +++++++-
3 files changed, 16 insertions(+), 3 deletions(-)
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 8a2f196ab995..5bfd38eaee3a 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -2276,7 +2276,8 @@ static void smc_find_rdma_v2_device_serv(struct smc_sock *new_smc,
goto not_found;
smc_v2_ext = smc_get_clc_v2_ext(pclc);
- if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext, NULL, NULL))
+ if (!smc_v2_ext ||
+ !smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext, NULL, NULL))
goto not_found;
/* prepare RDMA check */
diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index 66a43b97eede..f721d03efcbd 100644
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -352,7 +352,6 @@ static bool smc_clc_msg_prop_valid(struct smc_clc_msg_proposal *pclc)
struct smc_clc_msg_hdr *hdr = &pclc->hdr;
struct smc_clc_v2_extension *v2_ext;
- v2_ext = smc_get_clc_v2_ext(pclc);
pclc_prfx = smc_clc_proposal_get_prefix(pclc);
if (!pclc_prfx ||
pclc_prfx->ipv6_prefixes_cnt > SMC_CLC_MAX_V6_PREFIX)
@@ -369,6 +368,13 @@ static bool smc_clc_msg_prop_valid(struct smc_clc_msg_proposal *pclc)
sizeof(struct smc_clc_msg_trail))
return false;
} else {
+ v2_ext = smc_get_clc_v2_ext(pclc);
+ if ((hdr->typev2 != SMC_TYPE_N &&
+ (!v2_ext || v2_ext->hdr.eid_cnt > SMC_CLC_MAX_UEID)) ||
+ (smcd_indicated(hdr->typev2) &&
+ v2_ext->hdr.ism_gid_cnt > SMCD_CLC_MAX_V2_GID_ENTRIES))
+ return false;
+
if (ntohs(hdr->length) !=
sizeof(*pclc) +
sizeof(struct smc_clc_msg_smcd) +
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index ac8de6a177fa..23afa4df862e 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -380,8 +380,14 @@ static inline struct smc_clc_v2_extension *
smc_get_clc_v2_ext(struct smc_clc_msg_proposal *prop)
{
struct smc_clc_msg_smcd *prop_smcd = smc_get_clc_msg_smcd(prop);
+ u16 max_offset;
- if (!prop_smcd || !ntohs(prop_smcd->v2_ext_offset))
+ max_offset = offsetof(struct smc_clc_msg_proposal_area, pclc_v2_ext) -
+ offsetof(struct smc_clc_msg_proposal_area, pclc_smcd) -
+ offsetofend(struct smc_clc_msg_smcd, v2_ext_offset);
+
+ if (!prop_smcd || !ntohs(prop_smcd->v2_ext_offset) ||
+ ntohs(prop_smcd->v2_ext_offset) > max_offset)
return NULL;
return (struct smc_clc_v2_extension *)
--
2.24.3 (Apple Git-128)
