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    Subject[PATCH 3.16 056/305] VMCI: Resource wildcard match fixed
    3.16.63-rc1 review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Jorgen Hansen <jhansen@vmware.com>

    commit 11924ba5e671d6caef1516923e2bd8c72929a3fe upstream.

    When adding a VMCI resource, the check for an existing entry
    would ignore that the new entry could be a wildcard. This could
    result in multiple resource entries that would match a given
    handle. One disastrous outcome of this is that the
    refcounting used to ensure that delayed callbacks for VMCI
    datagrams have run before the datagram is destroyed can be
    wrong, since the refcount could be increased on the duplicate
    entry. This in turn leads to a use after free bug. This issue
    was discovered by Hangbin Liu using KASAN and syzkaller.

    Fixes: bc63dedb7d46 ("VMCI: resource object implementation")
    Reported-by: Hangbin Liu <liuhangbin@gmail.com>
    Reviewed-by: Adit Ranadive <aditr@vmware.com>
    Reviewed-by: Vishnu Dasa <vdasa@vmware.com>
    Signed-off-by: Jorgen Hansen <jhansen@vmware.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
    [bwh: Backported to 3.16: Drop the version change.]
    Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
    ---
    --- a/drivers/misc/vmw_vmci/vmci_resource.c
    +++ b/drivers/misc/vmw_vmci/vmci_resource.c
    @@ -56,7 +56,8 @@ static struct vmci_resource *vmci_resour

    if (r->type == type &&
    rid == handle.resource &&
    - (cid == handle.context || cid == VMCI_INVALID_ID)) {
    + (cid == handle.context || cid == VMCI_INVALID_ID ||
    + handle.context == VMCI_INVALID_ID)) {
    resource = r;
    break;
    }
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