> Eduard Zingerman wrote:
>
> On Wed, 2024-08-28 at 22:45 -0700, Eduard Zingerman wrote:
>
> [...]
>
>> I will prepare a test case.
>> Probably tomorrow.
>
> Please find test in the attachment. This test triggers KASAN error
> report as in another attachment. (I enabled CONFIG_KASAN using
> menuconfig on top of regular selftest config).
>
Thank you for writing the selftest for me.
> On Fri, Aug 23, 2024 at 3:43 AM Jeongjun Park <aha310510@xxxxxxxxx> wrote:
>
> [...]
>
>> diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
>> index 520f49f422fe..5c24ea1a65a4 100644
>> --- a/kernel/bpf/btf.c
>> +++ b/kernel/bpf/btf.c
>> @@ -823,6 +823,9 @@ 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;
>> +
>
> I think that correct fix would be as follows:
>
> ---
>
> diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
> index edad152cee8e..d583d76fcace 100644
> --- a/kernel/bpf/btf.c
> +++ b/kernel/bpf/btf.c
> @@ -820,7 +820,6 @@ static bool btf_name_valid_section(const struct btf *btf, u32 offset)
>
> /* set a limit on identifier length */
> src_limit = src + KSYM_NAME_LEN;
> - src++;
> while (*src && src < src_limit) {
> if (!isprint(*src))
> return false;
However, this patch is logically flawed.
It will return true for invalid names with
length 1 and src[0] being NULL. So I think
it's better to stick with the original patch.
>
> <bad-name-test.patch>
> <bad-name-kasan-report.txt>
