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| author | Alison Schofield <alison.schofield@intel.com> | 2026-08-21 15:25:14 -0700 |
|---|---|---|
| committer | Dave Jiang <dave.jiang@intel.com> | 2026-08-31 09:41:15 -0700 |
| commit | b212e37113f82bfb018e045adfa28dadc3e1bd6d (patch) | |
| tree | 1258cf0977090128ff5c8cff0b3e55036d9dc64a | |
| parent | cee9395acd8043be0644b25c34bfa86623f2b935 (diff) | |
| download | linux-next-b212e37113f82bfb018e045adfa28dadc3e1bd6d.tar.gz linux-next-b212e37113f82bfb018e045adfa28dadc3e1bd6d.zip | |
cxl/region: Guard against a missing peer mapping
When two endpoints share a dport, both must be mapped by the port.
sashiko-bot reports that a missing peer mapping could result in a NULL
pointer dereference during region creation.
No caller can reach this today. Guard it anyway so a future violation
of the mapping requirement fails region creation rather than causing
an oops.
Reported-by: sashiko-bot@kernel.org
Link: https://sashiko.dev/#/patchset/cover.1787255388.git.alison.schofield%40intel.com?part=3
Assisted-by: Claude:claude-opus-5
Signed-off-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Richard Cheng <icheng@nvidia.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://patch.msgid.link/20260821222515.2675707-1-alison.schofield@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
| -rw-r--r-- | drivers/cxl/core/region.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index 27e63e6dab7c..75b8092e6dc2 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -1367,7 +1367,8 @@ static int check_last_peer(struct cxl_endpoint_decoder *cxled, /* * If this position wants to share a dport with the last endpoint mapped * then that endpoint, at index 'position - distance', must also be - * mapped by this dport. + * mapped by this dport. An endpoint that this port does not map at all + * fails that requirement. */ if (pos < distance) { dev_dbg(&cxlr->dev, "%s:%s: cannot host %s:%s at %d\n", @@ -1378,7 +1379,7 @@ static int check_last_peer(struct cxl_endpoint_decoder *cxled, cxled_peer = p->targets[pos - distance]; cxlmd_peer = cxled_to_memdev(cxled_peer); ep_peer = cxl_ep_load(port, cxlmd_peer); - if (ep->dport != ep_peer->dport) { + if (!ep_peer || ep->dport != ep_peer->dport) { dev_dbg(&cxlr->dev, "%s:%s: %s:%s pos %d mismatched peer %s:%s\n", dev_name(port->uport_dev), dev_name(&port->dev), |