From: Yuan Chen <chenyuan@kylinos.cn>
Date: Wed, 18 Jun 2025 01:19:33 +0000 (+0800)
Subject: libbpf: Fix null pointer dereference in btf_dump__free on allocation failure
X-Git-Tag: v6.6.96~60
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9b9a87f0bd1817108562b67a95ee4d5cbec636fe;p=thirdparty%2Fkernel%2Fstable.git

libbpf: Fix null pointer dereference in btf_dump__free on allocation failure

[ Upstream commit aa485e8789d56a4573f7c8d000a182b749eaa64d ]

When btf_dump__new() fails to allocate memory for the internal hashmap
(btf_dump->type_names), it returns an error code. However, the cleanup
function btf_dump__free() does not check if btf_dump->type_names is NULL
before attempting to free it. This leads to a null pointer dereference
when btf_dump__free() is called on a btf_dump object.

Fixes: 351131b51c7a ("libbpf: add btf_dump API for BTF-to-C conversion")
Signed-off-by: Yuan Chen <chenyuan@kylinos.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20250618011933.11423-1-chenyuan_fl@163.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
index ebf56d21d08ee..cf4db51b99eb5 100644
--- a/tools/lib/bpf/btf_dump.c
+++ b/tools/lib/bpf/btf_dump.c
@@ -225,6 +225,9 @@ static void btf_dump_free_names(struct hashmap *map)
 	size_t bkt;
 	struct hashmap_entry *cur;
 
+	if (!map)
+		return;
+
 	hashmap__for_each_entry(map, cur, bkt)
 		free((void *)cur->pkey);