From: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
commit c9f115564561af63db662791e9a35fcf1dfefd2a upstream.
The commit 9e926acda0c2 ("libbpf: Find correct module BTFs for struct_ops maps and progs.")
sets a newly added field (value_type_btf_obj_fd) to -1 in libbpf when
the caller of the libbpf's bpf_map_create did not define this field by
passing a NULL "opts" or passing in a "opts" that does not cover this
new field. OPT_HAS(opts, field) is used to decide if the field is
defined or not:
((opts) && opts->sz >= offsetofend(typeof(*(opts)), field))
Once OPTS_HAS decided the field is not defined, that field should
be set to 0. For this particular new field (value_type_btf_obj_fd),
its corresponding map_flags "BPF_F_VTYPE_BTF_OBJ_FD" is not set.
Thus, the kernel does not treat it as an fd field.
Fixes: 9e926acda0c2 ("libbpf: Find correct module BTFs for struct_ops maps and progs.")
Reported-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Signed-off-by: Martin KaFai Lau <martin.lau@xxxxxxxxxx>
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Link: https://lore.kernel.org/bpf/20240124224418.2905133-1-martin.lau@xxxxxxxxx
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
tools/lib/bpf/bpf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -192,7 +192,7 @@ int bpf_map_create(enum bpf_map_type map
attr.btf_key_type_id = OPTS_GET(opts, btf_key_type_id, 0);
attr.btf_value_type_id = OPTS_GET(opts, btf_value_type_id, 0);
attr.btf_vmlinux_value_type_id = OPTS_GET(opts, btf_vmlinux_value_type_id, 0);
- attr.value_type_btf_obj_fd = OPTS_GET(opts, value_type_btf_obj_fd, -1);
+ attr.value_type_btf_obj_fd = OPTS_GET(opts, value_type_btf_obj_fd, 0);
attr.inner_map_fd = OPTS_GET(opts, inner_map_fd, 0);
attr.map_flags = OPTS_GET(opts, map_flags, 0);
Patches currently in stable-queue which might be from martin.lau@xxxxxxxxxx are
queue-6.6/libbpf-ensure-undefined-bpf_attr-field-stays-0.patch
queue-6.6/ipv6-avoid-possible-null-deref-in-rt6_uncached_list_.patch
queue-6.6/sock_map-add-a-cond_resched-in-sock_hash_free.patch
queue-6.6/libbpf-find-correct-module-btfs-for-struct_ops-maps-.patch
