5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Guangguan Wang <guangguan.wang@xxxxxxxxxxxxxxxxx>
[ Upstream commit 9ab332deb671d8f7e66d82a2ff2b3f715bc3a4ad ]
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: 5c21c4ccafe8 ("net/smc: determine accepted ISM devices")
Signed-off-by: Guangguan Wang <guangguan.wang@xxxxxxxxxxxxxxxxx>
Reviewed-by: Wen Gu <guwen@xxxxxxxxxxxxxxxxx>
Reviewed-by: D. Wythe <alibuda@xxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/smc/smc_clc.h | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index 986dcd5db3ed..78a94b9122b6 100644
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -311,9 +311,15 @@ 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 *)
--
2.39.5
