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 19:08:34 +0000 (11:08 -0800)
commit894e62f5e5fb0b6e8d0e3026178707facfe963ef
treec83a1513fb32a7c3e01de2e5862588a3ec623697
parent56628c1936aea563d3e4e2eaddb2efb4a0acdc87
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