diff options
| author | NeilBrown <neilb@suse.de> | 2022-01-17 08:36:53 +0300 |
|---|---|---|
| committer | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2022-02-08 17:14:26 +0300 |
| commit | b49ea673e119f59c71645e2f65b3ccad857c90ee (patch) | |
| tree | f2c725e739f87b03ccbc0cababb25d71026b1f9a | |
| parent | 63db37e99ac17f575766c9317f927c8d4c6e8cdf (diff) | |
| download | linux-b49ea673e119f59c71645e2f65b3ccad857c90ee.tar.xz | |
SUNRPC: lock against ->sock changing during sysfs read
->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@suse.de>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
| -rw-r--r-- | net/sunrpc/sysfs.c | 5 | ||||
| -rw-r--r-- | net/sunrpc/xprtsock.c | 7 |
2 files changed, 10 insertions, 2 deletions
diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c index b64a0286b182..05c758da6a92 100644 --- a/net/sunrpc/sysfs.c +++ b/net/sunrpc/sysfs.c @@ -115,11 +115,14 @@ static ssize_t rpc_sysfs_xprt_srcaddr_show(struct kobject *kobj, } sock = container_of(xprt, struct sock_xprt, xprt); - if (kernel_getsockname(sock->sock, (struct sockaddr *)&saddr) < 0) + mutex_lock(&sock->recv_mutex); + if (sock->sock == NULL || + kernel_getsockname(sock->sock, (struct sockaddr *)&saddr) < 0) goto out; ret = sprintf(buf, "%pISc\n", &saddr); out: + mutex_unlock(&sock->recv_mutex); xprt_put(xprt); return ret + 1; } diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 69b6ee5a5fd1..0f39e08ee580 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); |