From: NeilBrown neilb@suse.de

mainline inclusion from mainline-v5.17-rc4 commit b49ea673e119f59c71645e2f65b3ccad857c90ee category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IADG5L CVE: CVE-2022-48816

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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->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

Conflicts: net/sunrpc/sysfs.c [Did not backport e44773daf851d.] Signed-off-by: Liu Jian liujian56@huawei.com --- 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 0666f981618a..8d9a27b25ca5 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -1676,7 +1676,12 @@ 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);