58 lines
2.0 KiB
Diff
58 lines
2.0 KiB
Diff
From 8e9652b0b616a3704b5cb5a3dccb2c239e16ab9c Mon Sep 17 00:00:00 2001
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From: Maxime Coquelin <maxime.coquelin@redhat.com>
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Date: Tue, 21 Apr 2020 18:17:43 +0200
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Subject: vhost: fix vring index check
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vhost_user_check_and_alloc_queue_pair() is used to extract
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a vring index from a payload. This function validates the
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index and is called early on in when performing message
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handling. Most message handlers depend on it correctly
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validating the vring index.
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Depending on the message type the vring index is in
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different parts of the payload. The function contains a
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switch/case for each type and copies the index. This is
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stored in a uint16. This index is then validated. Depending
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on the message, the source index is an unsigned int. If
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integer truncation occurs (uint->uint16) the top 16 bits
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of the index are never validated.
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When they are used later on (e.g. in
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vhost_user_set_vring_num() or vhost_user_set_vring_addr())
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it can lead to out of bound indexing. The out of bound
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indexed data gets written to, and hence this can cause
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memory corruption.
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This patch fixes this vulnerability by declaring vring
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index as an unsigned int in
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vhost_user_check_and_alloc_queue_pair().
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Fixes: 160cbc815b41 ("vhost: remove a hack on queue allocation")
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This issue has been assigned CVE-2020-10723
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Reported-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
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Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
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Reviewed-by: Xiaolong Ye <xiaolong.ye@intel.com>
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Reviewed-by: Ilja Van Sprundel <ivansprundel@ioactive.com>
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---
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lib/librte_vhost/vhost_user.c | 2 +-
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1 file changed, 1 insertion(+), 1 deletion(-)
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diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
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index 02962fc..d196142 100644
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--- a/lib/librte_vhost/vhost_user.c
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+++ b/lib/librte_vhost/vhost_user.c
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@@ -2508,7 +2508,7 @@ static int
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vhost_user_check_and_alloc_queue_pair(struct virtio_net *dev,
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struct VhostUserMsg *msg)
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{
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- uint16_t vring_idx;
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+ uint32_t vring_idx;
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switch (msg->request.master) {
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case VHOST_USER_SET_VRING_KICK:
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--
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cgit v1.0
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