Commit a29e220d authored by Guangguan Wang's avatar Guangguan Wang Committed by David S. Miller
Browse files

net/smc: check iparea_offset and ipv6_prefixes_cnt when receiving proposal msg 



When receiving proposal msg in server, the field iparea_offset
and the field ipv6_prefixes_cnt in proposal msg are from the
remote client and can not be fully trusted. Especially the
field iparea_offset, once exceed the max value, there has the
chance to access wrong address, and crash may happen.

This patch checks iparea_offset and ipv6_prefixes_cnt before using them.

Fixes: e7b7a64a ("smc: support variable CLC proposal messages")
Signed-off-by: default avatarGuangguan Wang <guangguan.wang@linux.alibaba.com>
Reviewed-by: default avatarWen Gu <guwen@linux.alibaba.com>
Reviewed-by: default avatarD. Wythe <alibuda@linux.alibaba.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 679e9ddc

net/smc/af_smc.c

+5 −1
Original line number Diff line number Diff line
@@ -2032,6 +2032,8 @@ static int smc_listen_prfx_check(struct smc_sock *new_smc, 
	if (pclc->hdr.typev1 == SMC_TYPE_N)

		return 0;

	pclc_prfx = smc_clc_proposal_get_prefix(pclc);

	if (!pclc_prfx)

		return -EPROTO;

	if (smc_clc_prfx_match(newclcsock, pclc_prfx))

		return SMC_CLC_DECL_DIFFPREFIX;
@@ -2221,7 +2223,9 @@ static void smc_find_ism_v1_device_serv(struct smc_sock *new_smc, 
	int rc = 0;



	/* check if ISM V1 is available */

	if (!(ini->smcd_version & SMC_V1) || !smcd_indicated(ini->smc_type_v1))

	if (!(ini->smcd_version & SMC_V1) ||

	    !smcd_indicated(ini->smc_type_v1) ||

	    !pclc_smcd)

		goto not_found;

	ini->is_smcd = true; /* prepare ISM check */

	ini->ism_peer_gid[0].gid = ntohll(pclc_smcd->ism.gid);

net/smc/smc_clc.c

+4 −0
Original line number Diff line number Diff line
@@ -354,6 +354,10 @@ static bool smc_clc_msg_prop_valid(struct smc_clc_msg_proposal *pclc) 


	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)

		return false;



	if (hdr->version == SMC_V1) {

		if (hdr->typev1 == SMC_TYPE_N)

			return false;

net/smc/smc_clc.h

+5 −1
Original line number Diff line number Diff line
@@ -336,8 +336,12 @@ struct smc_clc_msg_decline_v2 { /* clc decline message */ 
static inline struct smc_clc_msg_proposal_prefix *

smc_clc_proposal_get_prefix(struct smc_clc_msg_proposal *pclc)

{

	u16 offset = ntohs(pclc->iparea_offset);



	if (offset > sizeof(struct smc_clc_msg_smcd))

		return NULL;

	return (struct smc_clc_msg_proposal_prefix *)

	       ((u8 *)pclc + sizeof(*pclc) + ntohs(pclc->iparea_offset));

	       ((u8 *)pclc + sizeof(*pclc) + offset);

}



static inline bool smcr_indicated(int smc_type)