From: Yonghong Song yhs@fb.com
[ Upstream commit beb3d47d1d3d7185bb401af628ad32ee204a9526 ]
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 16 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 Link: https://lore.kernel.org/r/20221123155759.2669749-1-yhs@fb.com Signed-off-by: Alexei Starovoitov ast@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 2aea877d644f..2b9872008428 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[16]; #define BTF_ID(prefix, name) #define BTF_ID_FLAGS(prefix, name, ...) #define BTF_ID_UNUSED