From: Yonghong Song <yhs@fb.com>
To: <bpf@vger.kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>, <kernel-team@fb.com>,
Martin KaFai Lau <martin.lau@kernel.org>,
kernel test robot <lkp@intel.com>,
Dan Carpenter <error27@gmail.com>,
Nathan Chancellor <nathan@kernel.org>
Subject: [PATCH bpf-next] bpf: Fix a BTF_ID_LIST bug with CONFIG_DEBUG_INFO_BTF not set
Date: Wed, 23 Nov 2022 07:57:59 -0800 [thread overview]
Message-ID: <20221123155759.2669749-1-yhs@fb.com> (raw)
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
next reply other threads:[~2022-11-23 15:59 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-23 15:57 Yonghong Song [this message]
2022-11-23 21:23 ` [PATCH bpf-next] bpf: Fix a BTF_ID_LIST bug with CONFIG_DEBUG_INFO_BTF not set Alexei Starovoitov
2022-11-23 21:30 ` patchwork-bot+netdevbpf
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20221123155759.2669749-1-yhs@fb.com \
--to=yhs@fb.com \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=error27@gmail.com \
--cc=kernel-team@fb.com \
--cc=lkp@intel.com \
--cc=martin.lau@kernel.org \
--cc=nathan@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox