Re: [syzbot] [PATCH] Test for aea6bf908d73

[syzbot <syzbot+bbe84a4010eeea00982d@syzkaller.appspotmail.com>]

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Subject: [PATCH] Test for aea6bf908d73
Author: eadavis@qq.com

please test uaf in nfc_alloc_send_skb

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git aea6bf908d73

diff --git a/net/nfc/llcp_commands.c b/net/nfc/llcp_commands.c
index e2680a3bef79..f5dd2d7e41de 100644
--- a/net/nfc/llcp_commands.c
+++ b/net/nfc/llcp_commands.c
@@ -738,7 +738,8 @@ int nfc_llcp_send_ui_frame(struct nfc_llcp_sock *sock, u8 ssap, u8 dsap,
 
 	pr_debug("Send UI frame len %zd\n", len);
 
-	local = sock->local;
+	local = nfc_llcp_find_local(sock->dev);
+	printk("finded: %p, d: %p, %s\n", local, sock->dev, __func__);
 	if (local == NULL)
 		return -ENODEV;
 
diff --git a/net/nfc/llcp_core.c b/net/nfc/llcp_core.c
index 1dac28136e6a..8d47f17da904 100644
--- a/net/nfc/llcp_core.c
+++ b/net/nfc/llcp_core.c
@@ -299,6 +299,7 @@ static struct nfc_llcp_local *nfc_llcp_remove_local(struct nfc_dev *dev)
 	spin_lock(&llcp_devices_lock);
 	list_for_each_entry_safe(local, tmp, &llcp_devices, list)
 		if (local->dev == dev) {
+			printk("deled: l: %p, d: %p, %s\n", local, dev, __func__);
 			list_del(&local->list);
 			spin_unlock(&llcp_devices_lock);
 			return local;
-- 
2.25.1