* [PATCH] bpf: Replace all non-returning strlcpy with strscpy
@ 2023-05-30 15:56 Azeem Shaikh
2023-05-30 23:17 ` Kees Cook
2023-05-31 11:10 ` patchwork-bot+netdevbpf
0 siblings, 2 replies; 3+ messages in thread
From: Azeem Shaikh @ 2023-05-30 15:56 UTC (permalink / raw)
To: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko
Cc: linux-hardening, Azeem Shaikh, Martin KaFai Lau, Song Liu,
Yonghong Song, John Fastabend, KP Singh, Stanislav Fomichev,
Hao Luo, Jiri Olsa, bpf, linux-kernel, Ilya Leoshkevich
strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89
Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
---
kernel/bpf/preload/bpf_preload_kern.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/bpf/preload/bpf_preload_kern.c b/kernel/bpf/preload/bpf_preload_kern.c
index b56f9f3314fd..0c63bc2cd895 100644
--- a/kernel/bpf/preload/bpf_preload_kern.c
+++ b/kernel/bpf/preload/bpf_preload_kern.c
@@ -23,9 +23,9 @@ static void free_links_and_skel(void)
static int preload(struct bpf_preload_info *obj)
{
- strlcpy(obj[0].link_name, "maps.debug", sizeof(obj[0].link_name));
+ strscpy(obj[0].link_name, "maps.debug", sizeof(obj[0].link_name));
obj[0].link = maps_link;
- strlcpy(obj[1].link_name, "progs.debug", sizeof(obj[1].link_name));
+ strscpy(obj[1].link_name, "progs.debug", sizeof(obj[1].link_name));
obj[1].link = progs_link;
return 0;
}
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] bpf: Replace all non-returning strlcpy with strscpy
2023-05-30 15:56 [PATCH] bpf: Replace all non-returning strlcpy with strscpy Azeem Shaikh
@ 2023-05-30 23:17 ` Kees Cook
2023-05-31 11:10 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: Kees Cook @ 2023-05-30 23:17 UTC (permalink / raw)
To: Azeem Shaikh
Cc: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko,
linux-hardening, Martin KaFai Lau, Song Liu, Yonghong Song,
John Fastabend, KP Singh, Stanislav Fomichev, Hao Luo, Jiri Olsa,
bpf, linux-kernel, Ilya Leoshkevich
On Tue, May 30, 2023 at 03:56:59PM +0000, Azeem Shaikh wrote:
> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
> No return values were used, so direct replacement is safe.
>
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
> [2] https://github.com/KSPP/linux/issues/89
>
> Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
--
Kees Cook
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] bpf: Replace all non-returning strlcpy with strscpy
2023-05-30 15:56 [PATCH] bpf: Replace all non-returning strlcpy with strscpy Azeem Shaikh
2023-05-30 23:17 ` Kees Cook
@ 2023-05-31 11:10 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: patchwork-bot+netdevbpf @ 2023-05-31 11:10 UTC (permalink / raw)
To: Azeem Shaikh
Cc: ast, daniel, andrii, linux-hardening, martin.lau, song, yhs,
john.fastabend, kpsingh, sdf, haoluo, jolsa, bpf, linux-kernel,
iii
Hello:
This patch was applied to bpf/bpf-next.git (master)
by Daniel Borkmann <daniel@iogearbox.net>:
On Tue, 30 May 2023 15:56:59 +0000 you wrote:
> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
> No return values were used, so direct replacement is safe.
>
> [...]
Here is the summary with links:
- bpf: Replace all non-returning strlcpy with strscpy
https://git.kernel.org/bpf/bpf-next/c/ffadc372529e
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
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2023-05-30 15:56 [PATCH] bpf: Replace all non-returning strlcpy with strscpy Azeem Shaikh
2023-05-30 23:17 ` Kees Cook
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