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author | Nicholas Bellinger <nab@linux-iscsi.org> | 2013-10-25 10:44:15 -0700 |
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committer | Nicholas Bellinger <nab@linux-iscsi.org> | 2013-10-25 11:03:34 -0700 |
commit | 60a01f558af9c48b0bb31f303c479e32721add3f (patch) | |
tree | 8155f05d553ee5d7d22117cdbda4222939bc939e /drivers/net/wireless/libertas/cmd.h | |
parent | 58932e96e438cd78f75e765d7b87ef39d3533d15 (diff) |
vhost/scsi: Fix incorrect usage of get_user_pages_fast write parameter
This patch addresses a long-standing bug where the get_user_pages_fast()
write parameter used for setting the underlying page table entry permission
bits was incorrectly set to write=1 for data_direction=DMA_TO_DEVICE, and
passed into get_user_pages_fast() via vhost_scsi_map_iov_to_sgl().
However, this parameter is intended to signal WRITEs to pinned userspace
PTEs for the virtio-scsi DMA_FROM_DEVICE -> READ payload case, and *not*
for the virtio-scsi DMA_TO_DEVICE -> WRITE payload case.
This bug would manifest itself as random process segmentation faults on
KVM host after repeated vhost starts + stops and/or with lots of vhost
endpoints + LUNs.
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Asias He <asias@redhat.com>
Cc: <stable@vger.kernel.org> # 3.6+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
Diffstat (limited to 'drivers/net/wireless/libertas/cmd.h')
0 files changed, 0 insertions, 0 deletions