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From: Dan Carpenter <dan.carpenter@oracle.com>
To: "Michael S. Tsirkin" <mst@redhat.com>,
	Xie Yongji <xieyongji@bytedance.com>
Cc: Jason Wang <jasowang@redhat.com>, Eli Cohen <elic@nvidia.com>,
	Parav Pandit <parav@nvidia.com>,
	virtualization@lists.linux-foundation.org,
	kernel-janitors@vger.kernel.org
Subject: [PATCH 1/2 v4] vduse: fix memory corruption in vduse_dev_ioctl()
Date: Wed, 8 Dec 2021 13:33:07 +0300	[thread overview]
Message-ID: <20211208103307.GA3778@kili> (raw)

The "config.offset" comes from the user.  There needs to a check to
prevent it being out of bounds.  The "config.offset" and
"dev->config_size" variables are both type u32.  So if the offset if
out of bounds then the "dev->config_size - config.offset" subtraction
results in a very high u32 value.  The out of bounds offset can result
in memory corruption.

Fixes: c8a6153b6c59 ("vduse: Introduce VDUSE - vDPA Device in Userspace")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v2: fix reversed if statement
v3: fix vhost_vdpa_config_validate() as pointed out by Yongji Xie.
v4: split the vhost_vdpa_config_validate() change into a separate path

 drivers/vdpa/vdpa_user/vduse_dev.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index c9204c62f339..1a206f95d73a 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -975,7 +975,8 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
 			break;
 
 		ret = -EINVAL;
-		if (config.length == 0 ||
+		if (config.offset > dev->config_size ||
+		    config.length == 0 ||
 		    config.length > dev->config_size - config.offset)
 			break;
 
-- 
2.20.1


WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: "Michael S. Tsirkin" <mst@redhat.com>,
	Xie Yongji <xieyongji@bytedance.com>
Cc: kernel-janitors@vger.kernel.org, Eli Cohen <elic@nvidia.com>,
	virtualization@lists.linux-foundation.org
Subject: [PATCH 1/2 v4] vduse: fix memory corruption in vduse_dev_ioctl()
Date: Wed, 8 Dec 2021 13:33:07 +0300	[thread overview]
Message-ID: <20211208103307.GA3778@kili> (raw)

The "config.offset" comes from the user.  There needs to a check to
prevent it being out of bounds.  The "config.offset" and
"dev->config_size" variables are both type u32.  So if the offset if
out of bounds then the "dev->config_size - config.offset" subtraction
results in a very high u32 value.  The out of bounds offset can result
in memory corruption.

Fixes: c8a6153b6c59 ("vduse: Introduce VDUSE - vDPA Device in Userspace")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v2: fix reversed if statement
v3: fix vhost_vdpa_config_validate() as pointed out by Yongji Xie.
v4: split the vhost_vdpa_config_validate() change into a separate path

 drivers/vdpa/vdpa_user/vduse_dev.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index c9204c62f339..1a206f95d73a 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -975,7 +975,8 @@ static long vduse_dev_ioctl(struct file *file, unsigned int cmd,
 			break;
 
 		ret = -EINVAL;
-		if (config.length == 0 ||
+		if (config.offset > dev->config_size ||
+		    config.length == 0 ||
 		    config.length > dev->config_size - config.offset)
 			break;
 
-- 
2.20.1

_______________________________________________
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             reply	other threads:[~2021-12-08 10:33 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-08 10:33 Dan Carpenter [this message]
2021-12-08 10:33 ` [PATCH 1/2 v4] vduse: fix memory corruption in vduse_dev_ioctl() Dan Carpenter
2021-12-08 10:33 ` [PATCH 2/2 v4] vdpa: check that offsets are within bounds Dan Carpenter
2021-12-08 10:33   ` Dan Carpenter
2021-12-09  2:12   ` Jason Wang
2021-12-09  2:12     ` Jason Wang
2021-12-09  2:35   ` Yongji Xie
2021-12-09  2:12 ` [PATCH 1/2 v4] vduse: fix memory corruption in vduse_dev_ioctl() Jason Wang
2021-12-09  2:12   ` Jason Wang
2021-12-09  2:34 ` Yongji Xie

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