[PATCH] RDMA/siw: Remove direct link to net_device

Bernard Metzler
2024-12-10T13:05:29Z

Maintain needed network interface information locally, but
remove a direct link to net_device which can become stale.
Accessing a stale net_device link was causing a 'KASAN:
slab-use-after-free' exception during siw_query_port()
call.

Fixes: bdcf26bf9b3a ("rdma/siw: network and RDMA core interface")
Reported-by: syzbot+4b87489410b4efd181bf@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=4b87489410b4efd181bf
Signed-off-by: Bernard Metzler <bmt@zurich.ibm.com>
---
drivers/infiniband/sw/siw/siw.h | 11 +++++++----
drivers/infiniband/sw/siw/siw_cm.c | 4 ++--
drivers/infiniband/sw/siw/siw_main.c | 18 ++++++++++++------
drivers/infiniband/sw/siw/siw_verbs.c | 11 ++++++-----
4 files changed, 27 insertions(+), 17 deletions(-)

diff --git a/drivers/infiniband/sw/siw/siw.h b/drivers/infiniband/sw/siw/siw.h
index 86d4d6a2170e..c8f75527b513 100644
--- a/drivers/infiniband/sw/siw/siw.h
+++ b/drivers/infiniband/sw/siw/siw.h
@@ -69,16 +69,19 @@ struct siw_pd {

struct siw_device {
struct ib_device base_dev;
- struct net_device *netdev;
struct siw_dev_cap attrs;

u32 vendor_part_id;
+ struct {
+ int ifindex;
+ enum ib_port_state state;
+ enum ib_mtu mtu;
+ enum ib_mtu max_mtu;
+ } ifinfo;
+
int numa_node;
char raw_gid[ETH_ALEN];

- /* physical port state (only one port per device) */
- enum ib_port_state state;
-
spinlock_t lock;

struct xarray qp_xa;
diff --git a/drivers/infiniband/sw/siw/siw_cm.c b/drivers/infiniband/sw/siw/siw_cm.c
index 86323918a570..451b50d92f7f 100644
--- a/drivers/infiniband/sw/siw/siw_cm.c
+++ b/drivers/infiniband/sw/siw/siw_cm.c
@@ -1780,7 +1780,7 @@ int siw_create_listen(struct iw_cm_id *id, int backlog)

/* For wildcard addr, limit binding to current device only */
if (ipv4_is_zeronet(laddr->sin_addr.s_addr))
- s->sk->sk_bound_dev_if = sdev->netdev->ifindex;
+ s->sk->sk_bound_dev_if = sdev->ifinfo.ifindex;

rv = s->ops->bind(s, (struct sockaddr *)laddr,
sizeof(struct sockaddr_in));
@@ -1798,7 +1798,7 @@ int siw_create_listen(struct iw_cm_id *id, int backlog)

/* For wildcard addr, limit binding to current device only */
if (ipv6_addr_any(&laddr->sin6_addr))
- s->sk->sk_bound_dev_if = sdev->netdev->ifindex;
+ s->sk->sk_bound_dev_if = sdev->ifinfo.ifindex;

rv = s->ops->bind(s, (struct sockaddr *)laddr,
sizeof(struct sockaddr_in6));
diff --git a/drivers/infiniband/sw/siw/siw_main.c b/drivers/infiniband/sw/siw/siw_main.c
index 17abef48abcd..4db10bdfb515 100644
--- a/drivers/infiniband/sw/siw/siw_main.c
+++ b/drivers/infiniband/sw/siw/siw_main.c
@@ -287,7 +287,6 @@ static struct siw_device *siw_device_create(struct net_device *netdev)
return NULL;

base_dev = &sdev->base_dev;
- sdev->netdev = netdev;

if (netdev->addr_len) {
memcpy(sdev->raw_gid, netdev->dev_addr,
@@ -354,6 +353,10 @@ static struct siw_device *siw_device_create(struct net_device *netdev)
atomic_set(&sdev->num_mr, 0);
atomic_set(&sdev->num_pd, 0);

+ sdev->ifinfo.max_mtu = ib_mtu_int_to_enum(netdev->max_mtu);
+ sdev->ifinfo.mtu = ib_mtu_int_to_enum(READ_ONCE(netdev->mtu));
+ sdev->ifinfo.ifindex = netdev->ifindex;
+
sdev->numa_node = dev_to_node(&netdev->dev);
spin_lock_init(&sdev->lock);

@@ -381,12 +384,12 @@ static int siw_netdev_event(struct notifier_block *nb, unsigned long event,

switch (event) {
case NETDEV_UP:
- sdev->state = IB_PORT_ACTIVE;
+ sdev->ifinfo.state = IB_PORT_ACTIVE;
siw_port_event(sdev, 1, IB_EVENT_PORT_ACTIVE);
break;

case NETDEV_DOWN:
- sdev->state = IB_PORT_DOWN;
+ sdev->ifinfo.state = IB_PORT_DOWN;
siw_port_event(sdev, 1, IB_EVENT_PORT_ERR);
break;

@@ -406,10 +409,13 @@ static int siw_netdev_event(struct notifier_block *nb, unsigned long event,
case NETDEV_CHANGEADDR:
siw_port_event(sdev, 1, IB_EVENT_LID_CHANGE);
break;
+
+ case NETDEV_CHANGEMTU:
+ sdev->ifinfo.mtu = ib_mtu_int_to_enum(READ_ONCE(netdev->mtu));
+ break;
/*
* Todo: Below netdev events are currently not handled.
*/
- case NETDEV_CHANGEMTU:
case NETDEV_CHANGE:
break;

@@ -444,9 +450,9 @@ static int siw_newlink(const char *basedev_name, struct net_device *netdev)
dev_dbg(&netdev->dev, "siw: new device\n");

if (netif_running(netdev) && netif_carrier_ok(netdev))
- sdev->state = IB_PORT_ACTIVE;
+ sdev->ifinfo.state = IB_PORT_ACTIVE;
else
- sdev->state = IB_PORT_DOWN;
+ sdev->ifinfo.state = IB_PORT_DOWN;

ib_mark_name_assigned_by_user(&sdev->base_dev);
rv = siw_device_register(sdev, basedev_name);
diff --git a/drivers/infiniband/sw/siw/siw_verbs.c b/drivers/infiniband/sw/siw/siw_verbs.c
index 986666c19378..3ab9c5170637 100644
--- a/drivers/infiniband/sw/siw/siw_verbs.c
+++ b/drivers/infiniband/sw/siw/siw_verbs.c
@@ -178,14 +178,15 @@ int siw_query_port(struct ib_device *base_dev, u32 port,

rv = ib_get_eth_speed(base_dev, port, &attr->active_speed,
&attr->active_width);
+
attr->gid_tbl_len = 1;
attr->max_msg_sz = -1;
- attr->max_mtu = ib_mtu_int_to_enum(sdev->netdev->mtu);
- attr->active_mtu = ib_mtu_int_to_enum(sdev->netdev->mtu);
- attr->phys_state = sdev->state == IB_PORT_ACTIVE ?
+ attr->max_mtu = sdev->ifinfo.max_mtu;
+ attr->active_mtu = sdev->ifinfo.mtu;
+ attr->phys_state = sdev->ifinfo.state == IB_PORT_ACTIVE ?
IB_PORT_PHYS_STATE_LINK_UP : IB_PORT_PHYS_STATE_DISABLED;
attr->port_cap_flags = IB_PORT_CM_SUP | IB_PORT_DEVICE_MGMT_SUP;
- attr->state = sdev->state;
+ attr->state = sdev->ifinfo.state;
/*
* All zero
*
@@ -519,7 +520,7 @@ int siw_query_qp(struct ib_qp *base_qp, struct ib_qp_attr *qp_attr,
qp_attr->cap.max_send_sge = qp->attrs.sq_max_sges;
qp_attr->cap.max_recv_wr = qp->attrs.rq_size;
qp_attr->cap.max_recv_sge = qp->attrs.rq_max_sges;
- qp_attr->path_mtu = ib_mtu_int_to_enum(sdev->netdev->mtu);
+ qp_attr->path_mtu = sdev->ifinfo.mtu;
qp_attr->max_rd_atomic = qp->attrs.irq_size;
qp_attr->max_dest_rd_atomic = qp->attrs.orq_size;

--
2.38.1