VMCI: Resource wildcard match fixed
authorJorgen Hansen <jhansen@vmware.com>
Fri, 21 Sep 2018 07:31:05 +0000 (00:31 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 13 Nov 2018 19:14:58 +0000 (11:14 -0800)
commita9ecbed15e83db8b2ff245c3b6138225e6f9783b
treea1da341541b308202732498c115883149051e28b
parent4f4850858f8584a45652ac83fe21feaf7b45c87c
VMCI: Resource wildcard match fixed

[ Upstream commit 11924ba5e671d6caef1516923e2bd8c72929a3fe ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/misc/vmw_vmci/vmci_driver.c
drivers/misc/vmw_vmci/vmci_resource.c