From: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Date: Wed, 12 Mar 2025 09:52:49 +0000 (+0100)
Subject: devlink: fix xa_alloc_cyclic() error handling
X-Git-Tag: v6.14~16^2~14^2~2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=f3b97b7d4bf316c3991e5634c9f4847c2df35478;p=thirdparty%2Flinux.git

devlink: fix xa_alloc_cyclic() error handling

In case of returning 1 from xa_alloc_cyclic() (wrapping) ERR_PTR(1) will
be returned, which will cause IS_ERR() to be false. Which can lead to
dereference not allocated pointer (rel).

Fix it by checking if err is lower than zero.

This wasn't found in real usecase, only noticed. Credit to Pierre.

Fixes: c137743bce02 ("devlink: introduce object and nested devlink relationship infra")
Signed-off-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/devlink/core.c b/net/devlink/core.c
index f49cd83f1955f..7203c39532fcc 100644
--- a/net/devlink/core.c
+++ b/net/devlink/core.c
@@ -117,7 +117,7 @@ static struct devlink_rel *devlink_rel_alloc(void)
 
 	err = xa_alloc_cyclic(&devlink_rels, &rel->index, rel,
 			      xa_limit_32b, &next, GFP_KERNEL);
-	if (err) {
+	if (err < 0) {
 		kfree(rel);
 		return ERR_PTR(err);
 	}