From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4845DC433EF for ; Tue, 23 Nov 2021 17:29:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233829AbhKWRc6 (ORCPT ); Tue, 23 Nov 2021 12:32:58 -0500 Received: from meesny.iki.fi ([195.140.195.201]:33868 "EHLO meesny.iki.fi" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233491AbhKWRc6 (ORCPT ); Tue, 23 Nov 2021 12:32:58 -0500 Received: from [172.16.24.131] (73-55.dynamonet.fi [85.134.55.73]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: tmb@iki.fi) by meesny.iki.fi (Postfix) with ESMTPSA id 5F2022006A; Tue, 23 Nov 2021 19:29:44 +0200 (EET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=iki.fi; s=meesny; t=1637688584; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2t98XDYERp7Yf0jPvOLKBXDZ3r+jBn7OEVeCLHGjBZg=; b=E1HkB57d+jxHUzeqEPIZEuK7OhOf33z3ZbQNo5yg470U4OVipPd2LJmp21JkwBnsg6K1cU BDRkwbWcV+pTbccoWYb1A8ycKKxK9jFDrjsPuAXeKVEx7hKG67Q4aU+2ziYtCSQM/TMc0F /cBqCfBqsKJa87Fq16Ohj+OoVLkTnOg= Message-ID: Date: Tue, 23 Nov 2021 19:29:43 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.3.2 Subject: Re: FAILED: patch "[PATCH] signal: Don't always set SA_IMMUTABLE for forced signals" failed to apply to 5.15-stable tree Content-Language: en-US To: gregkh@linuxfoundation.org, ebiederm@xmission.com, keescook@chromium.org, khuey@kylehuey.com, me@kylehuey.com, oliver.sang@intel.com, torvalds@linux-foundation.org Cc: stable@vger.kernel.org References: <163758427225348@kroah.com> From: Thomas Backlund In-Reply-To: <163758427225348@kroah.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit ARC-Authentication-Results: i=1; ORIGINATING; auth=pass smtp.auth=tmb@iki.fi smtp.mailfrom=tmb@iki.fi ARC-Seal: i=1; s=meesny; d=iki.fi; t=1637688584; a=rsa-sha256; cv=none; b=OX5QJOaH46oY3h1YEO6aOLNNl5r1+KLg4NOKUc4/t6irGGXU/n/oNzMgr+fOFVeNgeJwu6 rsr0QCig9DfichhavAlawyt+hDsR84ZvoVVRabuE6UBv4wPd2wcFBM4lcrQQZDZPWr88Wo qqFRO0xVCYUBtFV6ke4nhfjnpWRIES0= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=iki.fi; s=meesny; t=1637688584; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=2t98XDYERp7Yf0jPvOLKBXDZ3r+jBn7OEVeCLHGjBZg=; b=bgg8fmwJS+EVwenQhuhiHcn7RBlz9KzL8oO/5IrhruWwasD31q/q8k29Os/SdadVajcVeq gPyiJvGRmiRwyKZUATmLLHyLeSR+vzjOmck03d+ekbzzcbcwtFKXHRh7edHPYTytw/8voC puQZgWh5qSYsVZHZLIjHgq8RUImcMGw= Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org Den 2021-11-22 kl. 14:31, skrev gregkh@linuxfoundation.org: > > The patch below does not apply to the 5.15-stable tree. > If someone wants it applied there, or to any other stable or longterm > tree, then please email the backport, including the original git commit > id to . > > thanks, > > greg k-h It will apply if you add this one first: From 26d5badbccddcc063dc5174a2baffd13a23322aa Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 20 Oct 2021 12:43:59 -0500 Subject: [PATCH] signal: Implement force_fatal_sig and if the other patch for signal that has similar description should land in 5.15: From fcb116bc43c8c37c052530ead79872f8b2615711 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 18 Nov 2021 14:23:21 -0600 Subject: [PATCH] signal: Replace force_fatal_sig with force_exit_sig when in doubt then the list is looks something like: From 941edc5bf174b67f94db19817cbeab0a93e0c32a Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 20 Oct 2021 12:44:00 -0500 Subject: [PATCH] exit/syscall_user_dispatch: Send ordinary signals on failure From 83a1f27ad773b1d8f0460d3a676114c7651918cc Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 20 Oct 2021 12:43:53 -0500 Subject: [PATCH] signal/powerpc: On swapcontext failure force SIGSEGV From 9bc508cf0791c8e5a37696de1a046d746fcbd9d8 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 20 Oct 2021 12:43:57 -0500 Subject: [PATCH] signal/s390: Use force_sigsegv in default_trap_handler From c317d306d55079525c9610267fdaf3a8a6d2f08b Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 20 Oct 2021 12:44:01 -0500 Subject: [PATCH] signal/sparc32: Exit with a fatal signal when try_to_clear_window_buffer fails From 086ec444f86660e103de8945d0dcae9b67132ac9 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 20 Oct 2021 12:44:02 -0500 Subject: [PATCH] signal/sparc32: In setup_rt_frame and setup_fram use force_fatal_sig From 1fbd60df8a852d9c55de8cd3621899cf4c72a5b7 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 20 Oct 2021 12:43:56 -0500 Subject: [PATCH] signal/vm86_32: Properly send SIGSEGV when the vm86 state cannot be saved. From 695dd0d634df8903e5ead8aa08d326f63b23368a Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 20 Oct 2021 12:44:03 -0500 Subject: [PATCH] signal/x86: In emulate_vsyscall force a signal instead of calling do_exit From 26d5badbccddcc063dc5174a2baffd13a23322aa Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 20 Oct 2021 12:43:59 -0500 Subject: [PATCH] signal: Implement force_fatal_sig From e21294a7aaae32c5d7154b187113a04db5852e37 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Mon, 25 Oct 2021 10:50:57 -0500 Subject: [PATCH] signal: Replace force_sigsegv(SIGSEGV) with force_fatal_sig(SIGSEGV) From e349d945fac76bddc78ae1cb92a0145b427a87ce Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 18 Nov 2021 11:11:13 -0600 Subject: [PATCH] signal: Don't always set SA_IMMUTABLE for forced signals From fcb116bc43c8c37c052530ead79872f8b2615711 Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Thu, 18 Nov 2021 14:23:21 -0600 Subject: [PATCH] signal: Replace force_fatal_sig with force_exit_sig when in doubt Applying them in listed order on top of 5.14.4 and builds/runs on i586, x86_64, armv7hl, aarch64 -- Thomas > > ------------------ original commit in Linus's tree ------------------ > > From e349d945fac76bddc78ae1cb92a0145b427a87ce Mon Sep 17 00:00:00 2001 > From: "Eric W. Biederman" > Date: Thu, 18 Nov 2021 11:11:13 -0600 > Subject: [PATCH] signal: Don't always set SA_IMMUTABLE for forced signals > > Recently to prevent issues with SECCOMP_RET_KILL and similar signals > being changed before they are delivered SA_IMMUTABLE was added. > > Unfortunately this broke debuggers[1][2] which reasonably expect to be > able to trap synchronous SIGTRAP and SIGSEGV even when the target > process is not configured to handle those signals. > > Update force_sig_to_task to support both the case when we can allow > the debugger to intercept and possibly ignore the signal and the case > when it is not safe to let userspace know about the signal until the > process has exited. > > Suggested-by: Linus Torvalds > Reported-by: Kyle Huey > Reported-by: kernel test robot > Cc: stable@vger.kernel.org > [1] https://lkml.kernel.org/r/CAP045AoMY4xf8aC_4QU_-j7obuEPYgTcnQQP3Yxk=2X90jtpjw@mail.gmail.com > [2] https://lkml.kernel.org/r/20211117150258.GB5403@xsang-OptiPlex-9020 > Fixes: 00b06da29cf9 ("signal: Add SA_IMMUTABLE to ensure forced siganls do not get changed") > Link: https://lkml.kernel.org/r/877dd5qfw5.fsf_-_@email.froward.int.ebiederm.org > Reviewed-by: Kees Cook > Tested-by: Kees Cook > Tested-by: Kyle Huey > Signed-off-by: "Eric W. Biederman" > > diff --git a/kernel/signal.c b/kernel/signal.c > index 7c4b7ae714d4..7815e1bbeddc 100644 > --- a/kernel/signal.c > +++ b/kernel/signal.c > @@ -1298,6 +1298,12 @@ int do_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p > return ret; > } > > +enum sig_handler { > + HANDLER_CURRENT, /* If reachable use the current handler */ > + HANDLER_SIG_DFL, /* Always use SIG_DFL handler semantics */ > + HANDLER_EXIT, /* Only visible as the process exit code */ > +}; > + > /* > * Force a signal that the process can't ignore: if necessary > * we unblock the signal and change any SIG_IGN to SIG_DFL. > @@ -1310,7 +1316,8 @@ int do_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p > * that is why we also clear SIGNAL_UNKILLABLE. > */ > static int > -force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t, bool sigdfl) > +force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t, > + enum sig_handler handler) > { > unsigned long int flags; > int ret, blocked, ignored; > @@ -1321,9 +1328,10 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t, bool > action = &t->sighand->action[sig-1]; > ignored = action->sa.sa_handler == SIG_IGN; > blocked = sigismember(&t->blocked, sig); > - if (blocked || ignored || sigdfl) { > + if (blocked || ignored || (handler != HANDLER_CURRENT)) { > action->sa.sa_handler = SIG_DFL; > - action->sa.sa_flags |= SA_IMMUTABLE; > + if (handler == HANDLER_EXIT) > + action->sa.sa_flags |= SA_IMMUTABLE; > if (blocked) { > sigdelset(&t->blocked, sig); > recalc_sigpending_and_wake(t); > @@ -1343,7 +1351,7 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t, bool > > int force_sig_info(struct kernel_siginfo *info) > { > - return force_sig_info_to_task(info, current, false); > + return force_sig_info_to_task(info, current, HANDLER_CURRENT); > } > > /* > @@ -1660,7 +1668,7 @@ void force_fatal_sig(int sig) > info.si_code = SI_KERNEL; > info.si_pid = 0; > info.si_uid = 0; > - force_sig_info_to_task(&info, current, true); > + force_sig_info_to_task(&info, current, HANDLER_SIG_DFL); > } > > /* > @@ -1693,7 +1701,7 @@ int force_sig_fault_to_task(int sig, int code, void __user *addr > info.si_flags = flags; > info.si_isr = isr; > #endif > - return force_sig_info_to_task(&info, t, false); > + return force_sig_info_to_task(&info, t, HANDLER_CURRENT); > } > > int force_sig_fault(int sig, int code, void __user *addr > @@ -1813,7 +1821,8 @@ int force_sig_seccomp(int syscall, int reason, bool force_coredump) > info.si_errno = reason; > info.si_arch = syscall_get_arch(current); > info.si_syscall = syscall; > - return force_sig_info_to_task(&info, current, force_coredump); > + return force_sig_info_to_task(&info, current, > + force_coredump ? HANDLER_EXIT : HANDLER_CURRENT); > } > > /* For the crazy architectures that include trap information in > >