From f7c52345ccc96343c0a05bdea3121c8ac7b67d5f Mon Sep 17 00:00:00 2001 From: Kwangjin Ko Date: Tue, 2 Apr 2024 17:14:03 +0900 Subject: cxl/core: Fix initialization of mbox_cmd.size_out in get event Since mbox_cmd.size_out is overwritten with the actual output size in the function below, it needs to be initialized every time. cxl_internal_send_cmd -> __cxl_pci_mbox_send_cmd Problem scenario: 1) The size_out variable is initially set to the size of the mailbox. 2) Read an event. - size_out is set to 160 bytes(header 32B + one event 128B). - Two event are created while reading. 3) Read the new *two* events. - size_out is still set to 160 bytes. - Although the value of out_len is 288 bytes, only 160 bytes are copied from the mailbox register to the local variable. - record_count is set to 2. - Accessing records[1] will result in reading incorrect data. Fixes: 6ebe28f9ec72 ("cxl/mem: Read, trace, and clear events on driver load") Tested-by: Ira Weiny Reviewed-by: Ira Weiny Reviewed-by: Jonathan Cameron Signed-off-by: Kwangjin Ko Signed-off-by: Dave Jiang --- drivers/cxl/core/mbox.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/cxl') diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c index 50146161887d..f0f54aeccc87 100644 --- a/drivers/cxl/core/mbox.c +++ b/drivers/cxl/core/mbox.c @@ -958,13 +958,14 @@ static void cxl_mem_get_records_log(struct cxl_memdev_state *mds, .payload_in = &log_type, .size_in = sizeof(log_type), .payload_out = payload, - .size_out = mds->payload_size, .min_out = struct_size(payload, records, 0), }; do { int rc, i; + mbox_cmd.size_out = mds->payload_size; + rc = cxl_internal_send_cmd(mds, &mbox_cmd); if (rc) { dev_err_ratelimited(dev, -- cgit v1.2.3