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| author |   Sagi Grimberg <sagi@grimberg.me> | 2021-06-16 14:19:36 -0700 |
|---|---|---|
| committer |   Christoph Hellwig <hch@lst.de> | 2021-08-16 14:42:22 +0200 |
| commit | e7006de6c23803799be000a5dcce4d916a36541a (patch) | |
| tree | c8ae69e3cca3580db8680b7a9558ae07325d7860 /drivers/nvme/host/pci.c | |
| parent | nvme-tcp: don't check blk_mq_tag_to_rq when receiving pdu data (diff) | |
| download | linux-dev-e7006de6c23803799be000a5dcce4d916a36541a.tar.xz linux-dev-e7006de6c23803799be000a5dcce4d916a36541a.zip | |
nvme: code command_id with a genctr for use-after-free validation
We cannot detect a (perhaps buggy) controller that is sending us
a completion for a request that was already completed (for example
sending a completion twice), this phenomenon was seen in the wild
a few times.
So to protect against this, we use the upper 4 msbits of the nvme sqe
command_id to use as a 4-bit generation counter and verify it matches
the existing request generation that is incrementing on every execution.
The 16-bit command_id structure now is constructed by:
| xxxx | xxxxxxxxxxxx |
gen request tag
This means that we are giving up some possible queue depth as 12 bits
allow for a maximum queue depth of 4095 instead of 65536, however we
never create such long queues anyways so no real harm done.
Suggested-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Tested-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'drivers/nvme/host/pci.c')
| -rw-r--r-- | drivers/nvme/host/pci.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 4880badb26d4..0471c2c7d64b 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -1010,7 +1010,7 @@ static inline void nvme_handle_cqe(struct nvme_queue *nvmeq, u16 idx) return; } - req = blk_mq_tag_to_rq(nvme_queue_tagset(nvmeq), command_id); + req = nvme_find_rq(nvme_queue_tagset(nvmeq), command_id); if (unlikely(!req)) { dev_warn(nvmeq->dev->ctrl.device, "invalid id %d completed on queue %d\n", |