6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Yanfei Xu <yanfei.xu@xxxxxxxxx>
[ Upstream commit 55e268694e8b07026c88191f9b6949b6887d9ce3 ]
The function cxl_dvsec_rr_decode() retrieves and records DVSEC ranges
into info->dvsec_range[], regardless of whether it is non-zero range,
and the variable info->ranges indicates the number of non-zero ranges.
However, in cxl_hdm_decode_init(), the validation for
info->dvsec_range[] occurs in a for loop that iterates based on
info->ranges. It may result in zero range to be validated but non-zero
range not be validated, in turn, the number of allowed ranges is to be
0. Address it by only record non-zero ranges.
This fix is not urgent as it requires a configuration that zeroes out
the first dvsec range while populating the second. This has not been
observed, but it is theoretically possible. If this gets picked up for
-stable, no harm done, but there is no urgency to backport.
Fixes: 560f78559006 ("cxl/pci: Retrieve CXL DVSEC memory info")
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Signed-off-by: Yanfei Xu <yanfei.xu@xxxxxxxxx>
Reviewed-by: Alison Schofield <alison.schofield@xxxxxxxxx>
Link: https://patch.msgid.link/20240828084231.1378789-2-yanfei.xu@xxxxxxxxx
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/cxl/core/pci.c | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)
diff --git a/drivers/cxl/core/pci.c b/drivers/cxl/core/pci.c
index c963cd9e88d16..6edfd05466737 100644
--- a/drivers/cxl/core/pci.c
+++ b/drivers/cxl/core/pci.c
@@ -388,10 +388,6 @@ int cxl_dvsec_rr_decode(struct device *dev, int d,
size |= temp & CXL_DVSEC_MEM_SIZE_LOW_MASK;
if (!size) {
- info->dvsec_range[i] = (struct range) {
- .start = 0,
- .end = CXL_RESOURCE_NONE,
- };
continue;
}
@@ -409,12 +405,10 @@ int cxl_dvsec_rr_decode(struct device *dev, int d,
base |= temp & CXL_DVSEC_MEM_BASE_LOW_MASK;
- info->dvsec_range[i] = (struct range) {
+ info->dvsec_range[ranges++] = (struct range) {
.start = base,
.end = base + size - 1
};
-
- ranges++;
}
info->ranges = ranges;
--
2.43.0
