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author | Stefano Garzarella <sgarzare@redhat.com> | 2022-02-22 10:47:42 +0100 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2022-02-23 12:32:33 +0000 |
commit | a58da53ffd70294ebea8ecd0eb45fd0d74add9f9 (patch) | |
tree | 674e148b37fbe2fba93917635ed65ad26470ec23 /drivers/vhost | |
parent | 277f2bb14361790a70e4b3c649e794b75a91a597 (diff) | |
download | linux-a58da53ffd70294ebea8ecd0eb45fd0d74add9f9.tar.gz linux-a58da53ffd70294ebea8ecd0eb45fd0d74add9f9.tar.bz2 linux-a58da53ffd70294ebea8ecd0eb45fd0d74add9f9.zip |
vhost/vsock: don't check owner in vhost_vsock_stop() while releasing
vhost_vsock_stop() calls vhost_dev_check_owner() to check the device
ownership. It expects current->mm to be valid.
vhost_vsock_stop() is also called by vhost_vsock_dev_release() when
the user has not done close(), so when we are in do_exit(). In this
case current->mm is invalid and we're releasing the device, so we
should clean it anyway.
Let's check the owner only when vhost_vsock_stop() is called
by an ioctl.
When invoked from release we can not fail so we don't check return
code of vhost_vsock_stop(). We need to stop vsock even if it's not
the owner.
Fixes: 433fc58e6bf2 ("VSOCK: Introduce vhost_vsock.ko")
Cc: stable@vger.kernel.org
Reported-by: syzbot+1e3ea63db39f2b4440e0@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+3140b17cb44a7b174008@syzkaller.appspotmail.com
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/vhost')
-rw-r--r-- | drivers/vhost/vsock.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index d6ca1c7ad513..37f0b4274113 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -629,16 +629,18 @@ err: return ret; } -static int vhost_vsock_stop(struct vhost_vsock *vsock) +static int vhost_vsock_stop(struct vhost_vsock *vsock, bool check_owner) { size_t i; - int ret; + int ret = 0; mutex_lock(&vsock->dev.mutex); - ret = vhost_dev_check_owner(&vsock->dev); - if (ret) - goto err; + if (check_owner) { + ret = vhost_dev_check_owner(&vsock->dev); + if (ret) + goto err; + } for (i = 0; i < ARRAY_SIZE(vsock->vqs); i++) { struct vhost_virtqueue *vq = &vsock->vqs[i]; @@ -753,7 +755,12 @@ static int vhost_vsock_dev_release(struct inode *inode, struct file *file) * inefficient. Room for improvement here. */ vsock_for_each_connected_socket(vhost_vsock_reset_orphans); - vhost_vsock_stop(vsock); + /* Don't check the owner, because we are in the release path, so we + * need to stop the vsock device in any case. + * vhost_vsock_stop() can not fail in this case, so we don't need to + * check the return code. + */ + vhost_vsock_stop(vsock, false); vhost_vsock_flush(vsock); vhost_dev_stop(&vsock->dev); @@ -868,7 +875,7 @@ static long vhost_vsock_dev_ioctl(struct file *f, unsigned int ioctl, if (start) return vhost_vsock_start(vsock); else - return vhost_vsock_stop(vsock); + return vhost_vsock_stop(vsock, true); case VHOST_GET_FEATURES: features = VHOST_VSOCK_FEATURES; if (copy_to_user(argp, &features, sizeof(features))) |