Message ID | 20200801194440.246747-1-yepeilin.cs@gmail.com |
---|---|
State | Awaiting Upstream |
Delegated to: | David Miller |
Headers | show |
Series | [Linux-kernel-mentees,net] net/smc: Prevent kernel-infoleak in __smc_diag_dump() | expand |
On 8/1/20 9:44 PM, Peilin Ye wrote: > __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(). > > Cc: stable@vger.kernel.org > Fixes: 4b1b7d3b30a6 ("net/smc: add SMC-D diag support") > Suggested-by: Dan Carpenter <dan.carpenter@oracle.com> > Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com> > --- > Reference: https://lwn.net/Articles/417989/ > > $ pahole -C "smcd_diag_dmbinfo" net/smc/smc_diag.o > struct smcd_diag_dmbinfo { > __u32 linkid; /* 0 4 */ > > /* XXX 4 bytes hole, try to pack */ > > __u64 peer_gid __attribute__((__aligned__(8))); /* 8 8 */ > __u64 my_gid __attribute__((__aligned__(8))); /* 16 8 */ > __u64 token __attribute__((__aligned__(8))); /* 24 8 */ > __u64 peer_token __attribute__((__aligned__(8))); /* 32 8 */ > > /* size: 40, cachelines: 1, members: 5 */ > /* sum members: 36, holes: 1, sum holes: 4 */ > /* forced alignments: 4, forced holes: 1, sum forced holes: 4 */ > /* last cacheline: 40 bytes */ > } __attribute__((__aligned__(8))); > $ _ > Thanks, patch is added to our local library and will be part of our next shipment of smc patches for the net-tree. Regards, Ursula > 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; >
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;
__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(). Cc: stable@vger.kernel.org Fixes: 4b1b7d3b30a6 ("net/smc: add SMC-D diag support") Suggested-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com> --- Reference: https://lwn.net/Articles/417989/ $ pahole -C "smcd_diag_dmbinfo" net/smc/smc_diag.o struct smcd_diag_dmbinfo { __u32 linkid; /* 0 4 */ /* XXX 4 bytes hole, try to pack */ __u64 peer_gid __attribute__((__aligned__(8))); /* 8 8 */ __u64 my_gid __attribute__((__aligned__(8))); /* 16 8 */ __u64 token __attribute__((__aligned__(8))); /* 24 8 */ __u64 peer_token __attribute__((__aligned__(8))); /* 32 8 */ /* size: 40, cachelines: 1, members: 5 */ /* sum members: 36, holes: 1, sum holes: 4 */ /* forced alignments: 4, forced holes: 1, sum forced holes: 4 */ /* last cacheline: 40 bytes */ } __attribute__((__aligned__(8))); $ _ net/smc/smc_diag.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-)