diff mbox series

[meta-oe] libbpf: fix a segmentation fault error

Message ID 20250410042438.2515750-1-changqing.li@windriver.com
State Accepted
Headers show
Series [meta-oe] libbpf: fix a segmentation fault error | expand

Commit Message

Changqing Li April 10, 2025, 4:24 a.m. UTC 
From: Changqing Li <changqing.li@windriver.com>

A valid ELF file may contain a SHT_NOBITS .BTF section. This case is not
handled correctly in btf_parse_elf, which leads to a segfault.

Signed-off-by: Changqing Li <changqing.li@windriver.com>
---
 ...-empty-BTF-data-section-in-btf_parse.patch | 43 +++++++++++++++++++
 meta-oe/recipes-kernel/libbpf/libbpf_1.5.0.bb |  4 +-
 2 files changed, 46 insertions(+), 1 deletion(-)
 create mode 100644 meta-oe/recipes-kernel/libbpf/files/0001-libbpf-check-for-empty-BTF-data-section-in-btf_parse.patch
diff mbox series

Patch

diff --git a/meta-oe/recipes-kernel/libbpf/files/0001-libbpf-check-for-empty-BTF-data-section-in-btf_parse.patch b/meta-oe/recipes-kernel/libbpf/files/0001-libbpf-check-for-empty-BTF-data-section-in-btf_parse.patch
new file mode 100644
index 0000000000..873995b644
--- /dev/null
+++ b/meta-oe/recipes-kernel/libbpf/files/0001-libbpf-check-for-empty-BTF-data-section-in-btf_parse.patch
@@ -0,0 +1,43 @@ 
+From ff2eb6e134ebfc225b97b46182af3cc58ed481f6 Mon Sep 17 00:00:00 2001
+From: Changqing Li <changqing.li@windriver.com>
+Date: Thu, 10 Apr 2025 11:50:04 +0800
+Subject: [PATCH] libbpf: check for empty BTF data section in btf_parse_elf
+
+A valid ELF file may contain a SHT_NOBITS .BTF section. This case is
+not handled correctly in btf_parse_elf, which leads to a segfault.
+
+Add a null check for a buffer returned by elf_getdata() before
+proceeding with its processing.
+
+Bug report: https://github.com/libbpf/libbpf/issues/894
+
+Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
+Acked-by: Mykyta Yatsenko <mykyta.yatsenko5@gmail.com>
+
+Upstream-Status: Backport [https://github.com/kernel-patches/bpf-rc/commit/b02b669fd9398d246c8c9ae901c0d8f5bb36a588]
+
+Signed-off-by: Changqing Li <changqing.li@windriver.com>
+---
+ btf.c | 6 ++++++
+ 1 file changed, 6 insertions(+)
+
+diff --git a/btf.c b/btf.c
+index e9673c0e..21d38dcf 100644
+--- a/btf.c
++++ b/btf.c
+@@ -1199,6 +1199,12 @@ static struct btf *btf_parse_elf(const char *path, struct btf *base_btf,
+ 		goto done;
+ 	}
+ 
++	if (!secs.btf_data->d_buf) {
++		pr_warn("BTF data is empty in %s\n", path);
++		err = -ENODATA;
++		goto done;
++	}
++
+ 	if (secs.btf_base_data) {
+ 		dist_base_btf = btf_new(secs.btf_base_data->d_buf, secs.btf_base_data->d_size,
+ 					NULL);
+-- 
+2.34.1
+
diff --git a/meta-oe/recipes-kernel/libbpf/libbpf_1.5.0.bb b/meta-oe/recipes-kernel/libbpf/libbpf_1.5.0.bb
index 5f92939274..58bb7bca09 100644
--- a/meta-oe/recipes-kernel/libbpf/libbpf_1.5.0.bb
+++ b/meta-oe/recipes-kernel/libbpf/libbpf_1.5.0.bb
@@ -8,7 +8,9 @@  LIC_FILES_CHKSUM = "file://../LICENSE.LGPL-2.1;md5=b370887980db5dd40659b50909238
 
 DEPENDS = "zlib elfutils"
 
-SRC_URI = "git://github.com/libbpf/libbpf.git;protocol=https;branch=master"
+SRC_URI = "git://github.com/libbpf/libbpf.git;protocol=https;branch=master \
+           file://0001-libbpf-check-for-empty-BTF-data-section-in-btf_parse.patch \
+"
 SRCREV = "09b9e83102eb8ab9e540d36b4559c55f3bcdb95d"
 
 PACKAGE_ARCH = "${MACHINE_ARCH}"