From: Dan Williams <dan.j.williams@xxxxxxxxx>
commit 7701c8bef4f14bd9f7940c6ed0e6a73584115a96 upstream.
Decoders committed with 0-size lead to later crashes on shutdown as
__cxl_dpa_release() assumes a 'struct resource' has been established in
the in 'cxlds->dpa_res'. Just fail the driver load in this instance
since there are deeper problems with the enumeration or the setup when
this happens.
Fixes: 9c57cde0dcbd ("cxl/hdm: Enumerate allocated DPA")
Cc: <stable@xxxxxxxxxxxxxxx>
Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>
Reviewed-by: Alison Schofield <alison.schofield@xxxxxxxxx>
Link: https://lore.kernel.org/r/168149843516.792294.11872242648319572632.stgit@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/cxl/core/hdm.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
--- a/drivers/cxl/core/hdm.c
+++ b/drivers/cxl/core/hdm.c
@@ -219,8 +219,11 @@ static int __cxl_dpa_reserve(struct cxl_
lockdep_assert_held_write(&cxl_dpa_rwsem);
- if (!len)
- goto success;
+ if (!len) {
+ dev_warn(dev, "decoder%d.%d: empty reservation attempted\n",
+ port->id, cxled->cxld.id);
+ return -EINVAL;
+ }
if (cxled->dpa_res) {
dev_dbg(dev, "decoder%d.%d: existing allocation %pr assigned\n",
@@ -273,7 +276,6 @@ static int __cxl_dpa_reserve(struct cxl_
cxled->mode = CXL_DECODER_MIXED;
}
-success:
port->hdm_end++;
get_device(&cxled->cxld.dev);
return 0;
@@ -732,6 +734,13 @@ static int init_hdm_decoder(struct cxl_p
port->id, cxld->id);
return -ENXIO;
}
+
+ if (size == 0) {
+ dev_warn(&port->dev,
+ "decoder%d.%d: Committed with zero size\n",
+ port->id, cxld->id);
+ return -ENXIO;
+ }
port->commit_end = cxld->id;
} else {
/* unless / until type-2 drivers arrive, assume type-3 */
