[PATCH RESEND] ref_tracker: use %p instead of %px in debugfs dentry name

From: Jeff Layton
Date: Fri Aug 08 2025 - 07:46:02 EST


As Kees points out, this is a kernel address leak, and debugging is
not a sufficiently good reason to expose the real kernel address.

Fixes: 65b584f53611 ("ref_tracker: automatically register a file in debugfs for a ref_tracker_dir")
Reported-by: Kees Cook <kees@xxxxxxxxxx>
Closes: https://lore.kernel.org/netdev/202507301603.62E553F93@keescook/
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
Resending since I didn't get a response from Andrew. This time I've
included netdev in the mailing list in case Jakub wants to pick this up
instead.
---
lib/ref_tracker.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/ref_tracker.c b/lib/ref_tracker.c
index a9e6ffcff04b1da162a5a6add6bff075c2c9405e..cce12287708ea43e9eda9fe42f82a80423cea4e3 100644
--- a/lib/ref_tracker.c
+++ b/lib/ref_tracker.c
@@ -434,7 +434,7 @@ void ref_tracker_dir_debugfs(struct ref_tracker_dir *dir)
if (dentry && !xa_is_err(dentry))
return;

- ret = snprintf(name, sizeof(name), "%s@%px", dir->class, dir);
+ ret = snprintf(name, sizeof(name), "%s@%p", dir->class, dir);
name[sizeof(name) - 1] = '\0';

if (ret < sizeof(name)) {

---
base-commit: 260f6f4fda93c8485c8037865c941b42b9cba5d2
change-id: 20250731-reftrack-dbgfs-f99ad92068bc

Best regards,
--
Jeff Layton <jlayton@xxxxxxxxxx>