5.15-stable review patch. If anyone has any objections, please let me know.
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From: Guangguan Wang guangguan.wang@linux.alibaba.com
[ 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@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 Signed-off-by: Sasha Levin sashal@kernel.org --- 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 *)