6.6-stable review patch. If anyone has any objections, please let me know.
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From: farah kassabri fkassabri@habana.ai
[ Upstream commit 0165994c215f321e2d055368f89b424756e340eb ]
There is a potential race between user thread seeking to re-use a timestamp record with new interrupt id, while this record is still in the middle of interrupt handling and it is about to be freed. Imagine the driver set the record in_use to 0 and only then fill the free_node information. This might lead to unpleasant scenario where the new registration thread detects the record as free to use, and change the cq buff address. That will cause the free_node to get the wrong buffer address to put refcount to.
Signed-off-by: farah kassabri fkassabri@habana.ai Reviewed-by: Oded Gabbay ogabbay@kernel.org Signed-off-by: Oded Gabbay ogabbay@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/accel/habanalabs/common/irq.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/accel/habanalabs/common/irq.c b/drivers/accel/habanalabs/common/irq.c index b1010d206c2ef..813315cea4a7b 100644 --- a/drivers/accel/habanalabs/common/irq.c +++ b/drivers/accel/habanalabs/common/irq.c @@ -271,6 +271,9 @@ static int handle_registration_node(struct hl_device *hdev, struct hl_user_pendi free_node->cq_cb = pend->ts_reg_info.cq_cb; list_add(&free_node->free_objects_node, *free_list);
+ /* Mark TS record as free */ + pend->ts_reg_info.in_use = false; + return 0; }