Re: [LTP] [PATCH] cve-2015-3290: Fix tst_syscall() return value

Petr Vorel
2023-02-15T15:20:32Z

Hi all,

> The modify_ldt() syscall returns 32-bit signed integer value. Recent changes
> in tst_syscall() caused the value to be interpreted as unsigned on older
> kernels/glibc, which breaks the cve-2015-3290 test. Add explicit type cast
> to fix it.

Reviewed-by: Petr Vorel <pvorel@suse.cz>

This is caused by e5d2a05a9 ("regen.sh: Use intptr_t for tst_syscall return")
which changed returning tst_ret from int to intptr_t (which is also int for 32
bit archs, but long for 64 bit archs). This commit is also needed, thus I don't
suggest to revert it, but I wonder how many other tests it broke.

Kind regards,
Petr

> Signed-off-by: Martin Doucha <mdoucha@suse.cz>
> ---
> testcases/cve/cve-2015-3290.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)

> diff --git a/testcases/cve/cve-2015-3290.c b/testcases/cve/cve-2015-3290.c
> index f61d2809b..a2a8fcedd 100644
> --- a/testcases/cve/cve-2015-3290.c
> +++ b/testcases/cve/cve-2015-3290.c
> @@ -195,7 +195,8 @@ static void set_ldt(void)
> .useable = 0
> };

> - TEST(tst_syscall(__NR_modify_ldt, 1, &data_desc, sizeof(data_desc)));
> + TEST((int)tst_syscall(__NR_modify_ldt, 1, &data_desc,
> + sizeof(data_desc)));
> if (TST_RET == -EINVAL) {
> tst_brk(TCONF | TRERRNO,
> "modify_ldt: 16-bit data segments are probably disabled");