This is a note to let you know that I've just added the patch titled
net/smc: check smcd_v2_ext_offset when receiving proposal msg
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-smc-check-smcd_v2_ext_offset-when-receiving-prop.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 18aaa50b91ff8e97b808a42c2486fc6e746b01d2
Author: Guangguan Wang <guangguan.wang@xxxxxxxxxxxxxxxxx>
Date: Wed Dec 11 17:21:20 2024 +0800
net/smc: check smcd_v2_ext_offset when receiving proposal msg
[ 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>
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 *)
