* [PATCH bpf-next] bpf: Fix a BTF_ID_LIST bug with CONFIG_DEBUG_INFO_BTF not set
@ 2022-11-23 15:57 Yonghong Song
2022-11-23 21:23 ` Alexei Starovoitov
2022-11-23 21:30 ` patchwork-bot+netdevbpf
0 siblings, 2 replies; 3+ messages in thread
From: Yonghong Song @ 2022-11-23 15:57 UTC (permalink / raw)
To: bpf
Cc: Alexei Starovoitov, Andrii Nakryiko, Daniel Borkmann, kernel-team,
Martin KaFai Lau, kernel test robot, Dan Carpenter,
Nathan Chancellor
With CONFIG_DEBUG_INFO_BTF not set, we hit the following compilation error,
/.../kernel/bpf/verifier.c:8196:23: error: array index 6 is past the end of the array
(that has type 'u32[5]' (aka 'unsigned int[5]')) [-Werror,-Warray-bounds]
if (meta->func_id == special_kfunc_list[KF_bpf_cast_to_kern_ctx])
^ ~~~~~~~~~~~~~~~~~~~~~~~
/.../kernel/bpf/verifier.c:8174:1: note: array 'special_kfunc_list' declared here
BTF_ID_LIST(special_kfunc_list)
^
/.../include/linux/btf_ids.h:207:27: note: expanded from macro 'BTF_ID_LIST'
#define BTF_ID_LIST(name) static u32 __maybe_unused name[5];
^
/.../kernel/bpf/verifier.c:8443:19: error: array index 5 is past the end of the array
(that has type 'u32[5]' (aka 'unsigned int[5]')) [-Werror,-Warray-bounds]
btf_id == special_kfunc_list[KF_bpf_list_pop_back];
^ ~~~~~~~~~~~~~~~~~~~~
/.../kernel/bpf/verifier.c:8174:1: note: array 'special_kfunc_list' declared here
BTF_ID_LIST(special_kfunc_list)
^
/.../include/linux/btf_ids.h:207:27: note: expanded from macro 'BTF_ID_LIST'
#define BTF_ID_LIST(name) static u32 __maybe_unused name[5];
...
Fix the problem by increase the size of BTF_ID_LIST to 8 to avoid compilation error
and also prevent potentially unintended issue due to out-of-bound access.
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Reported-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Yonghong Song <yhs@fb.com>
---
include/linux/btf_ids.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h
index c9744efd202f..71d0ce707744 100644
--- a/include/linux/btf_ids.h
+++ b/include/linux/btf_ids.h
@@ -204,7 +204,7 @@ extern struct btf_id_set8 name;
#else
-#define BTF_ID_LIST(name) static u32 __maybe_unused name[5];
+#define BTF_ID_LIST(name) static u32 __maybe_unused name[8];
#define BTF_ID(prefix, name)
#define BTF_ID_FLAGS(prefix, name, ...)
#define BTF_ID_UNUSED
--
2.30.2
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH bpf-next] bpf: Fix a BTF_ID_LIST bug with CONFIG_DEBUG_INFO_BTF not set
2022-11-23 15:57 [PATCH bpf-next] bpf: Fix a BTF_ID_LIST bug with CONFIG_DEBUG_INFO_BTF not set Yonghong Song
@ 2022-11-23 21:23 ` Alexei Starovoitov
2022-11-23 21:30 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: Alexei Starovoitov @ 2022-11-23 21:23 UTC (permalink / raw)
To: Yonghong Song
Cc: bpf, Alexei Starovoitov, Andrii Nakryiko, Daniel Borkmann,
Kernel Team, Martin KaFai Lau, kernel test robot, Dan Carpenter,
Nathan Chancellor
On Wed, Nov 23, 2022 at 7:58 AM Yonghong Song <yhs@fb.com> wrote:
>
> With CONFIG_DEBUG_INFO_BTF not set, we hit the following compilation error,
> /.../kernel/bpf/verifier.c:8196:23: error: array index 6 is past the end of the array
> (that has type 'u32[5]' (aka 'unsigned int[5]')) [-Werror,-Warray-bounds]
> if (meta->func_id == special_kfunc_list[KF_bpf_cast_to_kern_ctx])
> ^ ~~~~~~~~~~~~~~~~~~~~~~~
> /.../kernel/bpf/verifier.c:8174:1: note: array 'special_kfunc_list' declared here
> BTF_ID_LIST(special_kfunc_list)
> ^
> /.../include/linux/btf_ids.h:207:27: note: expanded from macro 'BTF_ID_LIST'
> #define BTF_ID_LIST(name) static u32 __maybe_unused name[5];
> ^
> /.../kernel/bpf/verifier.c:8443:19: error: array index 5 is past the end of the array
> (that has type 'u32[5]' (aka 'unsigned int[5]')) [-Werror,-Warray-bounds]
> btf_id == special_kfunc_list[KF_bpf_list_pop_back];
> ^ ~~~~~~~~~~~~~~~~~~~~
> /.../kernel/bpf/verifier.c:8174:1: note: array 'special_kfunc_list' declared here
> BTF_ID_LIST(special_kfunc_list)
> ^
> /.../include/linux/btf_ids.h:207:27: note: expanded from macro 'BTF_ID_LIST'
> #define BTF_ID_LIST(name) static u32 __maybe_unused name[5];
> ...
>
> Fix the problem by increase the size of BTF_ID_LIST to 8 to avoid compilation error
> and also prevent potentially unintended issue due to out-of-bound access.
>
> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: Dan Carpenter <error27@gmail.com>
> Reported-by: Nathan Chancellor <nathan@kernel.org>
> Signed-off-by: Yonghong Song <yhs@fb.com>
> ---
> include/linux/btf_ids.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/btf_ids.h b/include/linux/btf_ids.h
> index c9744efd202f..71d0ce707744 100644
> --- a/include/linux/btf_ids.h
> +++ b/include/linux/btf_ids.h
> @@ -204,7 +204,7 @@ extern struct btf_id_set8 name;
>
> #else
>
> -#define BTF_ID_LIST(name) static u32 __maybe_unused name[5];
> +#define BTF_ID_LIST(name) static u32 __maybe_unused name[8];
Changed it to 16 while applying so we don't have to bump it
again in the near future when another special kfunc is added.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH bpf-next] bpf: Fix a BTF_ID_LIST bug with CONFIG_DEBUG_INFO_BTF not set
2022-11-23 15:57 [PATCH bpf-next] bpf: Fix a BTF_ID_LIST bug with CONFIG_DEBUG_INFO_BTF not set Yonghong Song
2022-11-23 21:23 ` Alexei Starovoitov
@ 2022-11-23 21:30 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: patchwork-bot+netdevbpf @ 2022-11-23 21:30 UTC (permalink / raw)
To: Yonghong Song
Cc: bpf, ast, andrii, daniel, kernel-team, martin.lau, lkp, error27,
nathan
Hello:
This patch was applied to bpf/bpf-next.git (master)
by Alexei Starovoitov <ast@kernel.org>:
On Wed, 23 Nov 2022 07:57:59 -0800 you wrote:
> With CONFIG_DEBUG_INFO_BTF not set, we hit the following compilation error,
> /.../kernel/bpf/verifier.c:8196:23: error: array index 6 is past the end of the array
> (that has type 'u32[5]' (aka 'unsigned int[5]')) [-Werror,-Warray-bounds]
> if (meta->func_id == special_kfunc_list[KF_bpf_cast_to_kern_ctx])
> ^ ~~~~~~~~~~~~~~~~~~~~~~~
> /.../kernel/bpf/verifier.c:8174:1: note: array 'special_kfunc_list' declared here
> BTF_ID_LIST(special_kfunc_list)
> ^
> /.../include/linux/btf_ids.h:207:27: note: expanded from macro 'BTF_ID_LIST'
> #define BTF_ID_LIST(name) static u32 __maybe_unused name[5];
> ^
> /.../kernel/bpf/verifier.c:8443:19: error: array index 5 is past the end of the array
> (that has type 'u32[5]' (aka 'unsigned int[5]')) [-Werror,-Warray-bounds]
> btf_id == special_kfunc_list[KF_bpf_list_pop_back];
> ^ ~~~~~~~~~~~~~~~~~~~~
> /.../kernel/bpf/verifier.c:8174:1: note: array 'special_kfunc_list' declared here
> BTF_ID_LIST(special_kfunc_list)
> ^
> /.../include/linux/btf_ids.h:207:27: note: expanded from macro 'BTF_ID_LIST'
> #define BTF_ID_LIST(name) static u32 __maybe_unused name[5];
> ...
>
> [...]
Here is the summary with links:
- [bpf-next] bpf: Fix a BTF_ID_LIST bug with CONFIG_DEBUG_INFO_BTF not set
https://git.kernel.org/bpf/bpf-next/c/beb3d47d1d3d
You are awesome, thank you!
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2022-11-23 15:57 [PATCH bpf-next] bpf: Fix a BTF_ID_LIST bug with CONFIG_DEBUG_INFO_BTF not set Yonghong Song
2022-11-23 21:23 ` Alexei Starovoitov
2022-11-23 21:30 ` patchwork-bot+netdevbpf
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