This is a note to let you know that I've just added the patch titled
cxl/core: Fix initialization of mbox_cmd.size_out in get event
to the 6.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cxl-core-fix-initialization-of-mbox_cmd.size_out-in-.patch
and it can be found in the queue-6.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 0ee83074fabb2ea114d12f16cf8b590f4986176a
Author: Kwangjin Ko <kwangjin.ko@xxxxxx>
Date: Tue Apr 2 17:14:03 2024 +0900
cxl/core: Fix initialization of mbox_cmd.size_out in get event
[ Upstream commit f7c52345ccc96343c0a05bdea3121c8ac7b67d5f ]
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 <ira.weiny@xxxxxxxxx>
Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Kwangjin Ko <kwangjin.ko@xxxxxx>
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 50146161887d5..f0f54aeccc872 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,
