From ce51f63e63c52a4e1eee4dd040fb0ba0af3b43ab Mon Sep 17 00:00:00 2001 From: Peilin Ye Date: Thu, 20 Aug 2020 16:30:52 +0200 Subject: [PATCH] net/smc: Prevent kernel-infoleak in __smc_diag_dump() __smc_diag_dump() is potentially copying uninitialized kernel stack memory into socket buffers, since the compiler may leave a 4-byte hole near the beginning of `struct smcd_diag_dmbinfo`. Fix it by initializing `dinfo` with memset(). Fixes: 4b1b7d3b30a6 ("net/smc: add SMC-D diag support") Suggested-by: Dan Carpenter Signed-off-by: Peilin Ye Signed-off-by: Ursula Braun Signed-off-by: David S. Miller --- net/smc/smc_diag.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) diff --git a/net/smc/smc_diag.c b/net/smc/smc_diag.c index e1f64f4ba236..da9ba6d1679b 100644 --- a/net/smc/smc_diag.c +++ b/net/smc/smc_diag.c @@ -170,13 +170,15 @@ static int __smc_diag_dump(struct sock *sk, struct sk_buff *skb, (req->diag_ext & (1 << (SMC_DIAG_DMBINFO - 1))) && !list_empty(&smc->conn.lgr->list)) { struct smc_connection *conn = &smc->conn; - struct smcd_diag_dmbinfo dinfo = { - .linkid = *((u32 *)conn->lgr->id), - .peer_gid = conn->lgr->peer_gid, - .my_gid = conn->lgr->smcd->local_gid, - .token = conn->rmb_desc->token, - .peer_token = conn->peer_token - }; + struct smcd_diag_dmbinfo dinfo; + + memset(&dinfo, 0, sizeof(dinfo)); + + dinfo.linkid = *((u32 *)conn->lgr->id); + dinfo.peer_gid = conn->lgr->peer_gid; + dinfo.my_gid = conn->lgr->smcd->local_gid; + dinfo.token = conn->rmb_desc->token; + dinfo.peer_token = conn->peer_token; if (nla_put(skb, SMC_DIAG_DMBINFO, sizeof(dinfo), &dinfo) < 0) goto errout; -- 2.39.5