From: Wentao Liang Date: Thu, 9 Apr 2026 02:22:33 +0000 (+0000) Subject: of: unittest: fix use-after-free in of_unittest_changeset() X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=faecdd423c27f0d6090156a435ba9dbbac0eaddb;p=thirdparty%2Fkernel%2Flinux.git of: unittest: fix use-after-free in of_unittest_changeset() The variable 'parent' is assigned the value of 'nchangeset' earlier in the function, meaning both point to the same struct device_node. The call to of_node_put(nchangeset) can decrement the reference count to zero and free the node if there are no other holders. After that, the code still uses 'parent' to check for the presence of a property and to read a string property, leading to a use-after-free. Fix this by moving the of_node_put() call after the last access to 'parent', avoiding the UAF. Fixes: 1c668ea65506 ("of: unittest: Use of_property_present()") Cc: stable@vger.kernel.org Signed-off-by: Wentao Liang Link: https://patch.msgid.link/20260409022233.418103-1-vulab@iscas.ac.cn Signed-off-by: Rob Herring (Arm) --- diff --git a/drivers/of/unittest.c b/drivers/of/unittest.c index 2940295843e6..eae7ebdf5130 100644 --- a/drivers/of/unittest.c +++ b/drivers/of/unittest.c @@ -896,8 +896,6 @@ static void __init of_unittest_changeset(void) unittest(!of_changeset_apply(&chgset), "apply failed\n"); - of_node_put(nchangeset); - /* Make sure node names are constructed correctly */ unittest((np = of_find_node_by_path("/testcase-data/changeset/n2/n21")), "'%pOF' not added\n", n21); @@ -919,6 +917,7 @@ static void __init of_unittest_changeset(void) if (!ret) unittest(strcmp(propstr, "hello") == 0, "original value not in updated property after revert"); + of_node_put(nchangeset); of_changeset_destroy(&chgset); of_node_put(n1);