[PATCH 5.15 327/731] of: overlay: fix null pointer dereferencing in find_dup_cset_node_entry() and find_dup_cset_prop()

Greg Kroah-Hartman
2022-12-28T15:10:42Z

From: ruanjinjie <ruanjinjie@huawei.com>

[ Upstream commit ee9d7a0e754568180a2f8ebc4aad226278a9116f ]

When kmalloc() fail to allocate memory in kasprintf(), fn_1 or fn_2 will
be NULL, and strcmp() will cause null pointer dereference.

Fixes: 2fe0e8769df9 ("of: overlay: check prevents multiple fragments touching same property")
Signed-off-by: ruanjinjie <ruanjinjie@huawei.com>
Link: https://lore.kernel.org/r/20221211023337.592266-1-ruanjinjie@huawei.com
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/of/overlay.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index d1187123c4fc..424682372417 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -547,7 +547,7 @@ static int find_dup_cset_node_entry(struct overlay_changeset *ovcs,

fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np);
fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np);
- node_path_match = !strcmp(fn_1, fn_2);
+ node_path_match = !fn_1 || !fn_2 || !strcmp(fn_1, fn_2);
kfree(fn_1);
kfree(fn_2);
if (node_path_match) {
@@ -582,7 +582,7 @@ static int find_dup_cset_prop(struct overlay_changeset *ovcs,

fn_1 = kasprintf(GFP_KERNEL, "%pOF", ce_1->np);
fn_2 = kasprintf(GFP_KERNEL, "%pOF", ce_2->np);
- node_path_match = !strcmp(fn_1, fn_2);
+ node_path_match = !fn_1 || !fn_2 || !strcmp(fn_1, fn_2);
kfree(fn_1);
kfree(fn_2);
if (node_path_match &&
--
2.35.1