This is a note to let you know that I've just added the patch titled bpf: Prevent decl_tag from being referenced in func_proto arg to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: bpf-prevent-decl_tag-from-being-referenced-in-func_p.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 2d4394b9841569a0115304b54faf79e0891ee0d4 Author: Stanislav Fomichev <sdf@xxxxxxxxxx> Date: Tue Nov 22 19:54:22 2022 -0800 bpf: Prevent decl_tag from being referenced in func_proto arg [ Upstream commit f17472d4599697d701aa239b4c475a506bccfd19 ] 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@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxx> Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx> Acked-by: Yonghong Song <yhs@xxxxxx> Link: https://lore.kernel.org/bpf/20221123035422.872531-2-sdf@xxxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 9232938e3f96..52e704860739 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -3675,6 +3675,11 @@ static int btf_func_proto_check(struct btf_verifier_env *env, 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))) {