Merge tag 'bpf-6.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Pull bpf fixes from Alexei Starovoitov:

 - Fix crash when btf_parse_base() returns an error (Martin Lau)

 - Fix out of bounds access in btf_name_valid_section() (Jeongjun Park)

* tag 'bpf-6.11-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  selftests/bpf: Add a selftest to check for incorrect names
  bpf: add check for invalid name in btf_name_valid_section()
  bpf: Fix a crash when btf_parse_base() returns an error pointer

2 files changed, 38 insertions, 2 deletions

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 520f49f422fe..a4e4f8d43ecf 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -823,9 +823,11 @@ static bool btf_name_valid_section(const struct btf *btf, u32 offset)
 	const char *src = btf_str_by_offset(btf, offset);
 	const char *src_limit;
 
+	if (!*src)
+		return false;
+
 	/* set a limit on identifier length */
 	src_limit = src + KSYM_NAME_LEN;
-	src++;
 	while (*src && src < src_limit) {
 		if (!isprint(*src))
 			return false;
@@ -6283,7 +6285,7 @@ static struct btf *btf_parse_module(const char *module_name, const void *data,
 
 errout:
 	btf_verifier_env_free(env);
-	if (base_btf != vmlinux_btf)
+	if (!IS_ERR(base_btf) && base_btf != vmlinux_btf)
 		btf_free(base_btf);
 	if (btf) {
 		kvfree(btf->data);
diff --git a/tools/testing/selftests/bpf/prog_tests/btf.c b/tools/testing/selftests/bpf/prog_tests/btf.c
index 00965a6e83bb..61de88cf4ad0 100644
--- a/tools/testing/selftests/bpf/prog_tests/btf.c
+++ b/tools/testing/selftests/bpf/prog_tests/btf.c
@@ -3551,6 +3551,40 @@ static struct btf_raw_test raw_tests[] = {
 	BTF_STR_SEC("\0x\0?.foo bar:buz"),
 },
 {
+	.descr = "datasec: name with non-printable first char not is ok",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),  /* [1] */
+		/* VAR x */                                     /* [2] */
+		BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_VAR, 0, 0), 1),
+		BTF_VAR_STATIC,
+		/* DATASEC ?.data */                            /* [3] */
+		BTF_TYPE_ENC(3, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4),
+		BTF_VAR_SECINFO_ENC(2, 0, 4),
+		BTF_END_RAW,
+	},
+	BTF_STR_SEC("\0x\0\7foo"),
+	.err_str = "Invalid name",
+	.btf_load_err = true,
+},
+{
+	.descr = "datasec: name '\\0' is not ok",
+	.raw_types = {
+		/* int */
+		BTF_TYPE_INT_ENC(0, BTF_INT_SIGNED, 0, 32, 4),  /* [1] */
+		/* VAR x */                                     /* [2] */
+		BTF_TYPE_ENC(1, BTF_INFO_ENC(BTF_KIND_VAR, 0, 0), 1),
+		BTF_VAR_STATIC,
+		/* DATASEC \0 */                                /* [3] */
+		BTF_TYPE_ENC(3, BTF_INFO_ENC(BTF_KIND_DATASEC, 0, 1), 4),
+		BTF_VAR_SECINFO_ENC(2, 0, 4),
+		BTF_END_RAW,
+	},
+	BTF_STR_SEC("\0x\0"),
+	.err_str = "Invalid name",
+	.btf_load_err = true,
+},
+{
 	.descr = "type name '?foo' is not ok",
 	.raw_types = {
 		/* union ?foo; */