linux-kernel - Re: [syzbot] Re: [syzbot] [kernel?] KMSAN: kernel-infoleak in vmci_host_unlocked

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <6854e1ac.a00a0220.137b3.002a.GAE@google.com>
Date: Thu, 19 Jun 2025 21:21:00 -0700
From: syzbot <syzbot+9b9124ae9b12d5af5d95@...kaller.appspotmail.com>
To: linux-kernel@...r.kernel.org
Subject: Re: [syzbot] Re: [syzbot] [kernel?] KMSAN: kernel-infoleak in
 vmci_host_unlocked_ioctl (3)

For archival purposes, forwarding an incoming command email to
linux-kernel@...r.kernel.org.

***

Subject: Re: [syzbot] [kernel?] KMSAN: kernel-infoleak in vmci_host_unlocked_ioctl (3)
Author: lizhi.xu@...driver.com

#syz test

diff --git a/drivers/misc/vmw_vmci/vmci_host.c b/drivers/misc/vmw_vmci/vmci_host.c
index b64944367ac5..fc5b49b05afd 100644
--- a/drivers/misc/vmw_vmci/vmci_host.c
+++ b/drivers/misc/vmw_vmci/vmci_host.c
@@ -385,14 +385,20 @@ static int vmci_host_do_send_datagram(struct vmci_host_dev *vmci_host_dev,
 		return -EINVAL;
 	}
 
-	dg = memdup_user((void __user *)(uintptr_t)send_info.addr,
-			 send_info.len);
-	if (IS_ERR(dg)) {
+	dg = kzalloc(send_info.len, GFP_KERNEL);
+
+	if (IS_ERR_OR_NULL(dg)) {
 		vmci_ioctl_err(
 			"cannot allocate memory to dispatch datagram\n");
 		return PTR_ERR(dg);
 	}
 
+	if (copy_from_user(dg, send_info.addr, send_info.len)) {
+		vmci_ioctl_err("copy datagram fails\n");
+		kfree(dg);
+		return -EFAULT;
+	}
+
 	if (VMCI_DG_SIZE(dg) != send_info.len) {
 		vmci_ioctl_err("datagram size mismatch\n");
 		kfree(dg);