在 2026/5/16 7:00, Edward Adam Davis 写道:
We must serialize calls to rxe_net_del() or risk a crash as syzbot
reported:
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
Call Trace:
udp_tunnel_sock_release+0x6d/0x80 net/ipv4/udp_tunnel_core.c:197
rxe_release_udp_tunnel drivers/infiniband/sw/rxe/rxe_net.c:294 [inline]
rxe_sock_put drivers/infiniband/sw/rxe/rxe_net.c:639 [inline]
rxe_net_del+0xfb/0x290 drivers/infiniband/sw/rxe/rxe_net.c:660
rxe_dellink+0x15/0x20 drivers/infiniband/sw/rxe/rxe.c:254
Jason Gunthorpe suggest placing the lock within rxe to protect its racy
implementation of rxe_net_del(), which looks like it is possibly also
triggered by NETDEV_UNREGISTER.
The patch addressing this issue in nldev_dellink() has already been
applied(0b28000b64f4); however, since the fix has now been relocated
to rxe, the corresponding remedial code in nldev has been removed.
Fixes: f1327abd6abe ("RDMA/rxe: Support RDMA link creation and destruction per net namespace")
Fixes: 0b28000b64f4 ("RDMA/nldev: Add mutual exclusion in nldev_dellink()")
Reported-by: <redacted>
Closes: https://syzkaller.appspot.com/bug?extid=d8f76778263ab65c2b21
Signed-off-by: Edward Adam Davis <redacted>
---
v1 -> v2: serialize calls to rxe net del
I looked through the commit. I am not sure if this commit should be sent to syzbot to verify.
Zhu Yanjun
quoted hunk ↗ jump to hunk
drivers/infiniband/core/nldev.c | 4 ----
drivers/infiniband/sw/rxe/rxe_net.c | 7 ++++++-
2 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/infiniband/core/nldev.c b/drivers/infiniband/core/nldev.c
index 3cb3cb7629fe..96c745d5bac4 100644
--- a/drivers/infiniband/core/nldev.c
+++ b/drivers/infiniband/core/nldev.c
@@ -1816,8 +1816,6 @@ static int nldev_newlink(struct sk_buff *skb, struct nlmsghdr *nlh,
return err;
}
-static DEFINE_MUTEX(nldev_dellink_mutex);
-
static int nldev_dellink(struct sk_buff *skb, struct nlmsghdr *nlh,
struct netlink_ext_ack *extack)
{@@ -1848,9 +1846,7 @@ static int nldev_dellink(struct sk_buff *skb, struct nlmsghdr *nlh,
* implicitly scoped to the driver supporting dynamic link deletion like RXE.
*/
if (device->link_ops && device->link_ops->dellink) {
- mutex_lock(&nldev_dellink_mutex);
err = device->link_ops->dellink(device);
- mutex_unlock(&nldev_dellink_mutex);
if (err)
return err;
}diff --git a/drivers/infiniband/sw/rxe/rxe_net.c b/drivers/infiniband/sw/rxe/rxe_net.c
index 50a2cb5405e2..92847e955ca2 100644
--- a/drivers/infiniband/sw/rxe/rxe_net.c
+++ b/drivers/infiniband/sw/rxe/rxe_net.c
@@ -642,6 +642,8 @@ static void rxe_sock_put(struct sock *sk,
}
}
+static DEFINE_MUTEX(rxe_net_del_mutex);
+
void rxe_net_del(struct ib_device *dev)
{
struct rxe_dev *rxe = container_of(dev, struct rxe_dev, ib_dev);@@ -649,9 +651,10 @@ void rxe_net_del(struct ib_device *dev)
struct sock *sk;
struct net *net;
+ mutex_lock(&rxe_net_del_mutex);
ndev = rxe_ib_device_get_netdev(&rxe->ib_dev);
if (!ndev)
- return;
+ goto out;
net = dev_net(ndev);
@@ -664,6 +667,8 @@ void rxe_net_del(struct ib_device *dev)
rxe_sock_put(sk, rxe_ns_pernet_set_sk6, net);
dev_put(ndev);
+out:
+ mutex_unlock(&rxe_net_del_mutex);
}
static void rxe_port_event(struct rxe_dev *rxe,