2020-04-04 20:39:12

by Sven Schnelle

Subject: [PATCH 1/2] selftests/vDSO: prevent SIGFPE if vdso_info.nbucket is zero

If vdso_info can't be parsed correctly, vdso_info.nbucket might
contain zero. Add a check and return NULL which will fail the
symbol lookup.

Signed-off-by: Sven Schnelle <[email protected]>
---
tools/testing/selftests/vDSO/parse_vdso.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/tools/testing/selftests/vDSO/parse_vdso.c b/tools/testing/selftests/vDSO/parse_vdso.c
index 1dbb4b87268f..8e5a70a24d9a 100644
--- a/tools/testing/selftests/vDSO/parse_vdso.c
+++ b/tools/testing/selftests/vDSO/parse_vdso.c
@@ -226,6 +226,9 @@ void *vdso_sym(const char *version, const char *name)
return 0;

ver_hash = elf_hash(version);
+ if (!vdso_info.nbucket)
+ return NULL;
+
ELF(Word) chain = vdso_info.bucket[elf_hash(name) % vdso_info.nbucket];

for (; chain != STN_UNDEF; chain = vdso_info.chain[chain]) {
--
2.17.1

2020-04-28 06:22:58

by Sven Schnelle

Subject: Re: [PATCH 1/2] selftests/vDSO: prevent SIGFPE if vdso_info.nbucket is zero

On Sat, Apr 04, 2020 at 10:37:03PM +0200, Sven Schnelle wrote:
> If vdso_info can't be parsed correctly, vdso_info.nbucket might
> contain zero. Add a check and return NULL which will fail the
> symbol lookup.

Ping?

>
> Signed-off-by: Sven Schnelle <[email protected]>
> ---
> tools/testing/selftests/vDSO/parse_vdso.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/tools/testing/selftests/vDSO/parse_vdso.c b/tools/testing/selftests/vDSO/parse_vdso.c
> index 1dbb4b87268f..8e5a70a24d9a 100644
> --- a/tools/testing/selftests/vDSO/parse_vdso.c
> +++ b/tools/testing/selftests/vDSO/parse_vdso.c
> @@ -226,6 +226,9 @@ void *vdso_sym(const char *version, const char *name)
> return 0;
>
> ver_hash = elf_hash(version);
> + if (!vdso_info.nbucket)
> + return NULL;
> +
> ELF(Word) chain = vdso_info.bucket[elf_hash(name) % vdso_info.nbucket];
>
> for (; chain != STN_UNDEF; chain = vdso_info.chain[chain]) {
> --
> 2.17.1
>