2025-07-29 12:01:58 +02:00

60 lines
2.0 KiB
Diff

From 00f61be94dfdc94e2cb60e0620af9c529531680d Mon Sep 17 00:00:00 2001
From: Achill Gilgenast <fossdd@pwned.life>
Date: Sat, 26 Jul 2025 20:27:24 +0200
Subject: [PATCH] FROMLIST: libbpf: avoid possible use of uninitialized mod_len
If not fn_name, mod_len does never get initialized which fails now with
gcc15 on Alpine Linux edge:
libbpf.c: In function 'find_kernel_btf_id.constprop':
libbpf.c:10100:33: error: 'mod_len' may be used uninitialized [-Werror=maybe-uninitialized]
10100 | if (mod_name && strncmp(mod->name, mod_name, mod_len) != 0)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
libbpf.c:10070:21: note: 'mod_len' was declared here
10070 | int ret, i, mod_len;
| ^~~~~~~
Link: https://lore.kernel.org/lkml/20250729094611.2065713-1-fossdd@pwned.life/
Fixes: 8f8a024272f3 ("libbpf: support "module: Function" syntax for tracing programs")
Signed-off-by: Achill Gilgenast <fossdd@pwned.life>
---
tools/lib/bpf/libbpf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index c8e29c52d28c..cdef24c31d11 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -10057,27 +10057,27 @@ static int libbpf_find_prog_btf_id(const char *name, __u32 attach_prog_fd, int t
btf__free(btf);
if (err <= 0) {
pr_warn("%s is not found in prog's BTF\n", name);
goto out;
}
out:
return err;
}
static int find_kernel_btf_id(struct bpf_object *obj, const char *attach_name,
enum bpf_attach_type attach_type,
int *btf_obj_fd, int *btf_type_id)
{
- int ret, i, mod_len;
+ int ret, i, mod_len = 0;
const char *fn_name, *mod_name = NULL;
fn_name = strchr(attach_name, ':');
if (fn_name) {
mod_name = attach_name;
mod_len = fn_name - mod_name;
fn_name++;
}
if (!mod_name || strncmp(mod_name, "vmlinux", mod_len) == 0) {
ret = find_attach_btf_id(obj->btf_vmlinux,
mod_name ? fn_name : attach_name,
attach_type);
--
2.50.1