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| author | Alexander Potapenko <glider@google.com> | 2022-11-04 18:58:49 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-11-09 15:40:03 +0100 |
| commit | e5b0d06d9b10f5f43101bd6598b076c347f9295f (patch) | |
| tree | a429edbb975caabee9a8ed4775f8c58adde5ca6e /drivers/misc/vmw_vmci | |
| parent | 92ca969ff8815f3feef2645199bd39bf594e5eeb (diff) | |
| download | linux-e5b0d06d9b10f5f43101bd6598b076c347f9295f.tar.gz | |
misc/vmw_vmci: fix an infoleak in vmci_host_do_receive_datagram()
`struct vmci_event_qp` allocated by qp_notify_peer() contains padding,
which may carry uninitialized data to the userspace, as observed by
KMSAN:
BUG: KMSAN: kernel-infoleak in instrument_copy_to_user ./include/linux/instrumented.h:121
instrument_copy_to_user ./include/linux/instrumented.h:121
_copy_to_user+0x5f/0xb0 lib/usercopy.c:33
copy_to_user ./include/linux/uaccess.h:169
vmci_host_do_receive_datagram drivers/misc/vmw_vmci/vmci_host.c:431
vmci_host_unlocked_ioctl+0x33d/0x43d0 drivers/misc/vmw_vmci/vmci_host.c:925
vfs_ioctl fs/ioctl.c:51
...
Uninit was stored to memory at:
kmemdup+0x74/0xb0 mm/util.c:131
dg_dispatch_as_host drivers/misc/vmw_vmci/vmci_datagram.c:271
vmci_datagram_dispatch+0x4f8/0xfc0 drivers/misc/vmw_vmci/vmci_datagram.c:339
qp_notify_peer+0x19a/0x290 drivers/misc/vmw_vmci/vmci_queue_pair.c:1479
qp_broker_attach drivers/misc/vmw_vmci/vmci_queue_pair.c:1662
qp_broker_alloc+0x2977/0x2f30 drivers/misc/vmw_vmci/vmci_queue_pair.c:1750
vmci_qp_broker_alloc+0x96/0xd0 drivers/misc/vmw_vmci/vmci_queue_pair.c:1940
vmci_host_do_alloc_queuepair drivers/misc/vmw_vmci/vmci_host.c:488
vmci_host_unlocked_ioctl+0x24fd/0x43d0 drivers/misc/vmw_vmci/vmci_host.c:927
...
Local variable ev created at:
qp_notify_peer+0x54/0x290 drivers/misc/vmw_vmci/vmci_queue_pair.c:1456
qp_broker_attach drivers/misc/vmw_vmci/vmci_queue_pair.c:1662
qp_broker_alloc+0x2977/0x2f30 drivers/misc/vmw_vmci/vmci_queue_pair.c:1750
Bytes 28-31 of 48 are uninitialized
Memory access of size 48 starts at ffff888035155e00
Data copied to user address 0000000020000100
Use memset() to prevent the infoleaks.
Also speculatively fix qp_notify_peer_local(), which may suffer from the
same problem.
Reported-by: syzbot+39be4da489ed2493ba25@syzkaller.appspotmail.com
Cc: stable <stable@kernel.org>
Fixes: 06164d2b72aa ("VMCI: queue pairs implementation.")
Signed-off-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Vishnu Dasa <vdasa@vmware.com>
Link: https://lore.kernel.org/r/20221104175849.2782567-1-glider@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/misc/vmw_vmci')
| -rw-r--r-- | drivers/misc/vmw_vmci/vmci_queue_pair.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/misc/vmw_vmci/vmci_queue_pair.c b/drivers/misc/vmw_vmci/vmci_queue_pair.c index e71068f7759b3..844264e1b88cc 100644 --- a/drivers/misc/vmw_vmci/vmci_queue_pair.c +++ b/drivers/misc/vmw_vmci/vmci_queue_pair.c @@ -854,6 +854,7 @@ static int qp_notify_peer_local(bool attach, struct vmci_handle handle) u32 context_id = vmci_get_context_id(); struct vmci_event_qp ev; + memset(&ev, 0, sizeof(ev)); ev.msg.hdr.dst = vmci_make_handle(context_id, VMCI_EVENT_HANDLER); ev.msg.hdr.src = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID, VMCI_CONTEXT_RESOURCE_ID); @@ -1467,6 +1468,7 @@ static int qp_notify_peer(bool attach, * kernel. */ + memset(&ev, 0, sizeof(ev)); ev.msg.hdr.dst = vmci_make_handle(peer_id, VMCI_EVENT_HANDLER); ev.msg.hdr.src = vmci_make_handle(VMCI_HYPERVISOR_CONTEXT_ID, VMCI_CONTEXT_RESOURCE_ID); |