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| author | Kees Cook <keescook@chromium.org> | 2022-02-08 00:57:17 -0800 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2022-02-10 19:08:54 -0800 |
| commit | 5c72263ef2fbe99596848f03758ae2dc593adf2c (patch) | |
| tree | 60249a1e125168780858cad5f5cebb87338f49ed /kernel/signal.c | |
| parent | 26291c54e111ff6ba87a164d85d4a4e134b7315c (diff) | |
| download | linux-stable-5c72263ef2fbe99596848f03758ae2dc593adf2c.tar.gz linux-stable-5c72263ef2fbe99596848f03758ae2dc593adf2c.tar.bz2 linux-stable-5c72263ef2fbe99596848f03758ae2dc593adf2c.zip | |
signal: HANDLER_EXIT should clear SIGNAL_UNKILLABLE
Fatal SIGSYS signals (i.e. seccomp RET_KILL_* syscall filter actions)
were not being delivered to ptraced pid namespace init processes. Make
sure the SIGNAL_UNKILLABLE doesn't get set for these cases.
Reported-by: Robert Święcki <robert@swiecki.net>
Suggested-by: "Eric W. Biederman" <ebiederm@xmission.com>
Fixes: 00b06da29cf9 ("signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>
Link: https://lore.kernel.org/lkml/878rui8u4a.fsf@email.froward.int.ebiederm.org
Diffstat (limited to 'kernel/signal.c')
| -rw-r--r-- | kernel/signal.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/kernel/signal.c b/kernel/signal.c index 38602738866e..9b04631acde8 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1342,9 +1342,10 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t, } /* * Don't clear SIGNAL_UNKILLABLE for traced tasks, users won't expect - * debugging to leave init killable. + * debugging to leave init killable. But HANDLER_EXIT is always fatal. */ - if (action->sa.sa_handler == SIG_DFL && !t->ptrace) + if (action->sa.sa_handler == SIG_DFL && + (!t->ptrace || (handler == HANDLER_EXIT))) t->signal->flags &= ~SIGNAL_UNKILLABLE; ret = send_signal(sig, info, t, PIDTYPE_PID); spin_unlock_irqrestore(&t->sighand->siglock, flags); |