[PATCH net 0/3] net/smc: fixes 2018-02-28

[PATCH net 0/3] net/smc: fixes 2018-02-28

[Ursula Braun]

Dave,

here are 3 smc bug fixes for the net-tree. Karsten's first patch is
the reworked version of last week's
   "[PATCH net-next 2/5] net/smc: fix structure size"
patch, now solved without using __packed, and now targetted for net
instead of net-next.

Thanks, Ursula

Davide Caratti (1):
  net/smc: fix NULL pointer dereference on sock_create_kern() error path

Karsten Graul (2):
  net/smc: use a constant for control message length
  net/smc: use link_id of server in confirm link reply

 net/smc/af_smc.c   | 4 +++-
 net/smc/smc_cdc.c  | 2 +-
 net/smc/smc_core.c | 3 ++-
 net/smc/smc_llc.c  | 2 +-
 4 files changed, 7 insertions(+), 4 deletions(-)

-- 
2.13.5

[PATCH net 1/3] net/smc: use a constant for control message length

[Ursula Braun]

From: Karsten Graul <kgraul@linux.vnet.ibm.com>

The sizeof(struct smc_cdc_msg) evaluates to 48 bytes instead of the
required 44 bytes. We need to use the constant value of
SMC_WR_TX_SIZE to set and check the control message length.

Signed-off-by: Karsten Graul <kgraul@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
---
 net/smc/smc_cdc.c  | 2 +-
 net/smc/smc_core.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c
index 3cd086e5bd28..b42395d24cba 100644
--- a/net/smc/smc_cdc.c
+++ b/net/smc/smc_cdc.c
@@ -269,7 +269,7 @@ static void smc_cdc_rx_handler(struct ib_wc *wc, void *buf)
 
 	if (wc->byte_len < offsetof(struct smc_cdc_msg, reserved))
 		return; /* short message */
-	if (cdc->len != sizeof(*cdc))
+	if (cdc->len != SMC_WR_TX_SIZE)
 		return; /* invalid message */
 	smc_cdc_msg_recv(cdc, link, wc->wr_id);
 }
diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 2424c7100aaf..053f0e66bec7 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -465,7 +465,7 @@ int smc_conn_create(struct smc_sock *smc, __be32 peer_in_addr,
 		rc = smc_link_determine_gid(conn->lgr);
 	}
 	conn->local_tx_ctrl.common.type = SMC_CDC_MSG_TYPE;
-	conn->local_tx_ctrl.len = sizeof(struct smc_cdc_msg);
+	conn->local_tx_ctrl.len = SMC_WR_TX_SIZE;
 #ifndef KERNEL_HAS_ATOMIC64
 	spin_lock_init(&conn->acurs_lock);
 #endif
-- 
2.13.5

[PATCH net 2/3] net/smc: use link_id of server in confirm link reply

[Ursula Braun]

From: Karsten Graul <kgraul@linux.vnet.ibm.com>

The CONFIRM LINK reply message must contain the link_id sent
by the server. And set the link_id explicitly when
initializing the link.

Signed-off-by: Karsten Graul <kgraul@linux.vnet.ibm.com>
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
---
 net/smc/smc_core.c | 1 +
 net/smc/smc_llc.c  | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 053f0e66bec7..645dd226177b 100644
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -177,6 +177,7 @@ static int smc_lgr_create(struct smc_sock *smc, __be32 peer_in_addr,
 
 	lnk = &lgr->lnk[SMC_SINGLE_LINK];
 	/* initialize link */
+	lnk->link_id = SMC_SINGLE_LINK;
 	lnk->smcibdev = smcibdev;
 	lnk->ibport = ibport;
 	lnk->path_mtu = smcibdev->pattr[ibport - 1].active_mtu;
diff --git a/net/smc/smc_llc.c b/net/smc/smc_llc.c
index 92fe4cc8c82c..b4aa4fcedb96 100644
--- a/net/smc/smc_llc.c
+++ b/net/smc/smc_llc.c
@@ -92,7 +92,7 @@ int smc_llc_send_confirm_link(struct smc_link *link, u8 mac[],
 	memcpy(confllc->sender_mac, mac, ETH_ALEN);
 	memcpy(confllc->sender_gid, gid, SMC_GID_SIZE);
 	hton24(confllc->sender_qp_num, link->roce_qp->qp_num);
-	/* confllc->link_num = SMC_SINGLE_LINK; already done by memset above */
+	confllc->link_num = link->link_id;
 	memcpy(confllc->link_uid, lgr->id, SMC_LGR_ID_SIZE);
 	confllc->max_links = SMC_LINKS_PER_LGR_MAX;
 	/* send llc message */
-- 
2.13.5

[PATCH net 3/3] net/smc: fix NULL pointer dereference on sock_create_kern() error path

[Ursula Braun]

From: Davide Caratti <dcaratti@redhat.com>

when sock_create_kern(..., a) returns an error, 'a' might not be a valid
pointer, so it shouldn't be dereferenced to read a->sk->sk_sndbuf and
and a->sk->sk_rcvbuf; not doing that caused the following crash:

general protection fault: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
    (ftrace buffer empty)
Modules linked in:
CPU: 0 PID: 4254 Comm: syzkaller919713 Not tainted 4.16.0-rc1+ #18
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:smc_create+0x14e/0x300 net/smc/af_smc.c:1410
RSP: 0018:ffff8801b06afbc8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff8801b63457c0 RCX: ffffffff85a3e746
RDX: 0000000000000004 RSI: 00000000ffffffff RDI: 0000000000000020
RBP: ffff8801b06afbf0 R08: 00000000000007c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff8801b6345c08 R14: 00000000ffffffe9 R15: ffffffff8695ced0
FS:  0000000001afb880(0000) GS:ffff8801db200000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000040 CR3: 00000001b0721004 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  __sock_create+0x4d4/0x850 net/socket.c:1285
  sock_create net/socket.c:1325 [inline]
  SYSC_socketpair net/socket.c:1409 [inline]
  SyS_socketpair+0x1c0/0x6f0 net/socket.c:1366
  do_syscall_64+0x282/0x940 arch/x86/entry/common.c:287
  entry_SYSCALL_64_after_hwframe+0x26/0x9b
RIP: 0033:0x4404b9
RSP: 002b:00007fff44ab6908 EFLAGS: 00000246 ORIG_RAX: 0000000000000035
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004404b9
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000000002b
RBP: 00007fff44ab6910 R08: 0000000000000002 R09: 00007fff44003031
R10: 0000000020000040 R11: 0000000000000246 R12: ffffffffffffffff
R13: 0000000000000006 R14: 0000000000000000 R15: 0000000000000000
Code: 48 c1 ea 03 80 3c 02 00 0f 85 b3 01 00 00 4c 8b a3 48 04 00 00 48
b8
00 00 00 00 00 fc ff df 49 8d 7c 24 20 48 89 fa 48 c1 ea 03 <80> 3c 02
00
0f 85 82 01 00 00 4d 8b 7c 24 20 48 b8 00 00 00 00
RIP: smc_create+0x14e/0x300 net/smc/af_smc.c:1410 RSP: ffff8801b06afbc8

Fixes: cd6851f30386 smc: remote memory buffers (RMBs)
Reported-and-tested-by: syzbot+aa0227369be2dcc26ebe@syzkaller.appspotmail.com
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
---
 net/smc/af_smc.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index da1a5cdefd13..8cc97834d4f6 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1406,8 +1406,10 @@ static int smc_create(struct net *net, struct socket *sock, int protocol,
 	smc->use_fallback = false; /* assume rdma capability first */
 	rc = sock_create_kern(net, PF_INET, SOCK_STREAM,
 			      IPPROTO_TCP, &smc->clcsock);
-	if (rc)
+	if (rc) {
 		sk_common_release(sk);
+		goto out;
+	}
 	smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
 	smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
 
-- 
2.13.5

Re: [PATCH net 0/3] net/smc: fixes 2018-02-28

[David Miller]

From: Ursula Braun <ubraun@linux.vnet.ibm.com>
Date: Wed, 28 Feb 2018 12:44:06 +0100

> here are 3 smc bug fixes for the net-tree. Karsten's first patch is
> the reworked version of last week's
>    "[PATCH net-next 2/5] net/smc: fix structure size"
> patch, now solved without using __packed, and now targetted for net
> instead of net-next.

Series applied, thank you.