6.1-stable review patch. If anyone has any objections, please let me know.
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From: Yanfei Xu yanfei.xu@intel.com
[ 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@huawei.com Signed-off-by: Yanfei Xu yanfei.xu@intel.com Reviewed-by: Alison Schofield alison.schofield@intel.com Link: https://patch.msgid.link/20240828084231.1378789-2-yanfei.xu@intel.com Signed-off-by: Dave Jiang dave.jiang@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 194c8024216df..8d92a24fd73d9 100644 --- a/drivers/cxl/core/pci.c +++ b/drivers/cxl/core/pci.c @@ -471,10 +471,6 @@ static 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; }
@@ -492,12 +488,10 @@ static 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;