From: Stanislav Fomichev <sdf@google.com>
Date: Tue, 22 Nov 2022 19:54:22 -0800
Subject: bpf: Prevent decl_tag from being referenced in func_proto arg
Patch-mainline: v6.2-rc1
Git-commit: f17472d4599697d701aa239b4c475a506bccfd19
References: git-fixes
Syzkaller managed to hit another decl_tag issue:
btf_func_proto_check kernel/bpf/btf.c:4506 [inline]
btf_check_all_types kernel/bpf/btf.c:4734 [inline]
btf_parse_type_sec+0x1175/0x1980 kernel/bpf/btf.c:4763
btf_parse kernel/bpf/btf.c:5042 [inline]
btf_new_fd+0x65a/0xb00 kernel/bpf/btf.c:6709
bpf_btf_load+0x6f/0x90 kernel/bpf/syscall.c:4342
__sys_bpf+0x50a/0x6c0 kernel/bpf/syscall.c:5034
__do_sys_bpf kernel/bpf/syscall.c:5093 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5091 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5091
do_syscall_64+0x54/0x70 arch/x86/entry/common.c:48
This seems similar to commit ea68376c8bed ("bpf: prevent decl_tag from being
referenced in func_proto") but for the argument.
Reported-by: syzbot+8dd0551dda6020944c5d@syzkaller.appspotmail.com
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20221123035422.872531-2-sdf@google.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
kernel/bpf/btf.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -4370,6 +4370,11 @@ static int btf_func_proto_check(struct b
break;
}
+ if (btf_type_is_resolve_source_only(arg_type)) {
+ btf_verifier_log_type(env, t, "Invalid arg#%u", i + 1);
+ return -EINVAL;
+ }
+
if (args[i].name_off &&
(!btf_name_offset_valid(btf, args[i].name_off) ||
!btf_name_valid_identifier(btf, args[i].name_off))) {