->sock can be set to NULL asynchronously unless ->recv_mutex is held.
So it is important to hold that mutex. Otherwise a sysfs read can
trigger an oops.
Commit 17f09d3f619a ("SUNRPC: Check if the xprt is connected before
handling sysfs reads") appears to attempt to fix this problem, but it
only narrows the race window.
Fixes: 17f09d3f619a ("SUNRPC: Check if the xprt is connected before handling sysfs reads")
Fixes: a8482488a7d6 ("SUNRPC query transport's source port")
Signed-off-by: NeilBrown <neilb@xxxxxxx>
---
net/sunrpc/xprtsock.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
index 9d34c71004fa..3f2b766e9f82 100644
--- a/net/sunrpc/xprtsock.c
+++ b/net/sunrpc/xprtsock.c
@@ -1641,7 +1641,12 @@ static int xs_get_srcport(struct sock_xprt *transport)
unsigned short get_srcport(struct rpc_xprt *xprt)
{
struct sock_xprt *sock = container_of(xprt, struct sock_xprt, xprt);
- return xs_sock_getport(sock->sock);
+ unsigned short ret = 0;
+ mutex_lock(&sock->recv_mutex);
+ if (sock->sock)
+ ret = xs_sock_getport(sock->sock);
+ mutex_unlock(&sock->recv_mutex);
+ return ret;
}
EXPORT_SYMBOL(get_srcport);
--
2.34.1
