diff options
| author | Jonathan Cameron <Jonathan.Cameron@huawei.com> | 2022-08-18 17:42:10 +0100 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2022-10-20 16:28:53 -0700 |
| commit | 2816e24b0510e0c185c0c46acff1ce7aa4c4443f (patch) | |
| tree | a9778e38a4b69218064b1e9e7b5ec830e56e74a6 /drivers/cxl | |
| parent | cf00b33058b196b4db928419dde68993b15a975b (diff) | |
cxl/region: Fix null pointer dereference due to pass through decoder commit
Not all decoders have a commit callback.
The CXL specification allows a host bridge with a single root port to
have no explicit HDM decoders. Currently the region driver assumes there
are none. As such the CXL core creates a special pass through decoder
instance without a commit callback.
Prior to this patch, the ->commit() callback was called unconditionally.
Thus a configuration with 1 Host Bridge, 1 Root Port, 1 switch with
multiple downstream ports below which there are multiple CXL type 3
devices results in a situation where committing the region causes a null
pointer dereference.
Reported-by: Bobo WL <lmw.bobo@gmail.com>
Fixes: 176baefb2eb5 ("cxl/hdm: Commit decoder state to hardware")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Vishal Verma <vishal.l.verma@intel.com>
Link: https://lore.kernel.org/r/20220818164210.2084-1-Jonathan.Cameron@huawei.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Diffstat (limited to 'drivers/cxl')
| -rw-r--r-- | drivers/cxl/core/region.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 401148016978..c49d9a5f1091 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -174,7 +174,8 @@ static int cxl_region_decode_commit(struct cxl_region *cxlr) iter = to_cxl_port(iter->dev.parent)) { cxl_rr = cxl_rr_load(iter, cxlr); cxld = cxl_rr->decoder; - rc = cxld->commit(cxld); + if (cxld->commit) + rc = cxld->commit(cxld); if (rc) break; } |