net/smc: check smcd_v2_ext_offset when receiving proposal msg

When receiving proposal msg in server, the field smcd_v2_ext_offset in
proposal msg is from the remote client and can not be fully trusted.
Once the value of smcd_v2_ext_offset exceed the max value, there has
the chance to access wrong address, and crash may happen.

This patch checks the value of smcd_v2_ext_offset before using it.

Fixes: 5c21c4ccaf ("net/smc: determine accepted ISM devices")
Signed-off-by: Guangguan Wang <guangguan.wang@linux.alibaba.com>
Reviewed-by: Wen Gu <guwen@linux.alibaba.com>
Reviewed-by: D. Wythe <alibuda@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Guangguan Wang 2024-12-11 17:21:20 +08:00 committed by David S. Miller
parent 7863c9f3d2
commit 9ab332deb6
2 changed files with 9 additions and 1 deletions

View File

@ -2147,6 +2147,8 @@ static void smc_find_ism_v2_device_serv(struct smc_sock *new_smc,
pclc_smcd = smc_get_clc_msg_smcd(pclc);
smc_v2_ext = smc_get_clc_v2_ext(pclc);
smcd_v2_ext = smc_get_clc_smcd_v2_ext(smc_v2_ext);
if (!pclc_smcd || !smc_v2_ext || !smcd_v2_ext)
goto not_found;
mutex_lock(&smcd_dev_list.mutex);
if (pclc_smcd->ism.chid) {

View File

@ -400,9 +400,15 @@ smc_get_clc_v2_ext(struct smc_clc_msg_proposal *prop)
static inline struct smc_clc_smcd_v2_extension *
smc_get_clc_smcd_v2_ext(struct smc_clc_v2_extension *prop_v2ext)
{
u16 max_offset = offsetof(struct smc_clc_msg_proposal_area, pclc_smcd_v2_ext) -
offsetof(struct smc_clc_msg_proposal_area, pclc_v2_ext) -
offsetof(struct smc_clc_v2_extension, hdr) -
offsetofend(struct smc_clnt_opts_area_hdr, smcd_v2_ext_offset);
if (!prop_v2ext)
return NULL;
if (!ntohs(prop_v2ext->hdr.smcd_v2_ext_offset))
if (!ntohs(prop_v2ext->hdr.smcd_v2_ext_offset) ||
ntohs(prop_v2ext->hdr.smcd_v2_ext_offset) > max_offset)
return NULL;
return (struct smc_clc_smcd_v2_extension *)