6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Guangguan Wang guangguan.wang@linux.alibaba.com
[ Upstream commit a29e220d3c8edbf0e1beb0f028878a4a85966556 ]
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: e7b7a64a8493 ("smc: support variable CLC proposal messages") 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/af_smc.c | 6 +++++- net/smc/smc_clc.c | 4 ++++ net/smc/smc_clc.h | 6 +++++- 3 files changed, 14 insertions(+), 2 deletions(-)
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index aeeb6e62361f..889709c35b1f 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -1988,6 +1988,8 @@ 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;
@@ -2153,7 +2155,9 @@ 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] = ntohll(pclc_smcd->ism.gid); diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c index 867df4522815..f734fdd90c81 100644 --- a/net/smc/smc_clc.c +++ b/net/smc/smc_clc.c @@ -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; diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h index 5fee545c9a10..08279081d438 100644 --- a/net/smc/smc_clc.h +++ b/net/smc/smc_clc.h @@ -303,8 +303,12 @@ 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)