nvme: ensure subsystem reset is single threaded

commit 1e866afd4bcdd01a70a5eddb4371158d3035ce03 upstream.

The subsystem reset writes to a register, so we have to ensure the
device state is capable of handling that otherwise the driver may access
unmapped registers. Use the state machine to ensure the subsystem reset
doesn't try to write registers on a device already undergoing this type
of reset.

BUG=b/246924488
TEST=presubmit,validation
RELEASE_NOTE=Fixes CVE-2022-3169 in the Linux kernel.

cos-patch: security-moderate
Link: https://bugzilla.kernel.org/show_bug.cgi?id=214771
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Change-Id: If1bce9edc8120cc4dbe1f913bb22692756d33456
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/39447
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Oleksandr Tymoshenko <ovt@google.com>
1 file changed