On Mon, Feb 13, 2017 at 10:37 PM, Andrei Vagin <ava...@virtuozzo.com> wrote:
> On Tue, Feb 07, 2017 at 03:18:51PM -0800, Kees Cook wrote:
>> The SECCOMP_RET_KILL filter return code has always killed the current
>> thread, not the entire process. Changing this as a side-effect of dumping
>> core isn't a safe thing to do (a few test suites have already flagged this
>> behavioral change). Instead, restore the RET_KILL semantics, but still
>> dump core when a RET_KILL delivers SIGSYS to a single-threaded process.
>>
>> Fixes: b25e67161c29 ("seccomp: dump core when using SECCOMP_RET_KILL")
>> Signed-off-by: Kees Cook <keesc...@chromium.org>
>
> All CRIU tests passed with this patch. Thanks!
>
> Acked-by: Andrei Vagin <ava...@virtuozzo.com>
Thanks for testing!
James, can you make sure this makes it into your -next tree for v4.11?
Thanks!
-Kees
>
>> ---
>> kernel/seccomp.c | 13 ++++++++-----
>> 1 file changed, 8 insertions(+), 5 deletions(-)
>>
>> diff --git a/kernel/seccomp.c b/kernel/seccomp.c
>> index f8f88ebcb3ba..e15185c28de5 100644
>> --- a/kernel/seccomp.c
>> +++ b/kernel/seccomp.c
>> @@ -643,11 +643,14 @@ static int __seccomp_filter(int this_syscall, const
>> struct seccomp_data *sd,
>> default: {
>> siginfo_t info;
>> audit_seccomp(this_syscall, SIGSYS, action);
>> - /* Show the original registers in the dump. */
>> - syscall_rollback(current, task_pt_regs(current));
>> - /* Trigger a manual coredump since do_exit skips it. */
>> - seccomp_init_siginfo(&info, this_syscall, data);
>> - do_coredump(&info);
>> + /* Dump core only if this is the last remaining thread. */
>> + if (get_nr_threads(current) == 1) {
>> + /* Show the original registers in the dump. */
>> + syscall_rollback(current, task_pt_regs(current));
>> + /* Trigger a manual coredump since do_exit skips it. */
>> + seccomp_init_siginfo(&info, this_syscall, data);
>> + do_coredump(&info);
>> + }
>> do_exit(SIGSYS);
>> }
>> }
>> --
>> 2.7.4
>>
>>
>> --
>> Kees Cook
>> Pixel Security
--
Kees Cook
Pixel Security
