From: Stanislav Fomichev <sdf@fomichev.me>
Date: Mon, 31 Mar 2025 14:28:14 +0000 (-0700)
Subject: bpf: add missing ops lock around dev_xdp_attach_link
X-Git-Tag: v6.15-rc1~19^2~30
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d996e412b2dfc079bd44bff5b3bc743fdb6d7c90;p=thirdparty%2Fkernel%2Flinux.git

bpf: add missing ops lock around dev_xdp_attach_link

Syzkaller points out that create_link path doesn't grab ops lock,
add it.

Reported-by: syzbot+08936936fe8132f91f1a@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/67e6b3e8.050a0220.2f068f.0079.GAE@google.com/
Fixes: 97246d6d21c2 ("net: hold netdev instance lock during ndo_bpf")
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250331142814.1887506-1-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---

diff --git a/net/core/dev.c b/net/core/dev.c
index be17e0660144f..5d20ff226d5e7 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -10284,7 +10284,9 @@ int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
 		goto unlock;
 	}
 
+	netdev_lock_ops(dev);
 	err = dev_xdp_attach_link(dev, &extack, link);
+	netdev_unlock_ops(dev);
 	rtnl_unlock();
 
 	if (err) {