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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        syzbot+15ec7391f3d6a1a7cc7d@syzkaller.appspotmail.com,
        Sabyrzhan Tasbolatov <snovitoll@gmail.com>
Subject: [PATCH 4.19 206/247] drivers/misc/vmw_vmci: restrict too big queue size in qp_host_alloc_queue
Date:   Mon,  1 Mar 2021 17:13:46 +0100
Message-Id: <20210301161041.754746654@linuxfoundation.org>
In-Reply-To: <20210301161031.684018251@linuxfoundation.org>
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From: Sabyrzhan Tasbolatov <snovitoll@gmail.com>

commit 2fd10bcf0310b9525b2af9e1f7aa9ddd87c3772e upstream.

syzbot found WARNING in qp_broker_alloc[1] in qp_host_alloc_queue()
when num_pages is 0x100001, giving queue_size + queue_page_size
bigger than KMALLOC_MAX_SIZE for kzalloc(), resulting order >= MAX_ORDER
condition.

queue_size + queue_page_size=0x8000d8, where KMALLOC_MAX_SIZE=0x400000.

[1]
Call Trace:
 alloc_pages include/linux/gfp.h:547 [inline]
 kmalloc_order+0x40/0x130 mm/slab_common.c:837
 kmalloc_order_trace+0x15/0x70 mm/slab_common.c:853
 kmalloc_large include/linux/slab.h:481 [inline]
 __kmalloc+0x257/0x330 mm/slub.c:3959
 kmalloc include/linux/slab.h:557 [inline]
 kzalloc include/linux/slab.h:682 [inline]
 qp_host_alloc_queue drivers/misc/vmw_vmci/vmci_queue_pair.c:540 [inline]
 qp_broker_create drivers/misc/vmw_vmci/vmci_queue_pair.c:1351 [inline]
 qp_broker_alloc+0x936/0x2740 drivers/misc/vmw_vmci/vmci_queue_pair.c:1739

Reported-by: syzbot+15ec7391f3d6a1a7cc7d@syzkaller.appspotmail.com
Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@gmail.com>
Link: https://lore.kernel.org/r/20210209102612.2112247-1-snovitoll@gmail.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/misc/vmw_vmci/vmci_queue_pair.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/misc/vmw_vmci/vmci_queue_pair.c
+++ b/drivers/misc/vmw_vmci/vmci_queue_pair.c
@@ -552,6 +552,9 @@ static struct vmci_queue *qp_host_alloc_
 
 	queue_page_size = num_pages * sizeof(*queue->kernel_if->u.h.page);
 
+	if (queue_size + queue_page_size > KMALLOC_MAX_SIZE)
+		return NULL;
+
 	queue = kzalloc(queue_size + queue_page_size, GFP_KERNEL);
 	if (queue) {
 		queue->q_header = NULL;