From patchwork Wed Sep 11 13:13:20 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleg Nesterov X-Patchwork-Id: 13800513 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 286611885A8 for ; Wed, 11 Sep 2024 13:13:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726060435; cv=none; b=f2FwEdEJyH6/psZGC4gN2AfN51Ap3v9GL+RLj05bDuRaZE+t6HeTyWkqSSpPiwI0YpLpn7OtRJBvLx2kIMs6j8DnTzxUOA2PtLNOsdhLeMK48QR39hJybbskBriIog5RR1ZzwrVojb0/z4oEJaqLhoEZLdMjKv3dtPO7QZ4KE00= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726060435; c=relaxed/simple; bh=lLQujuaQVsINKOcP87KS9IaW5lEIAgM6cp+Fl8ujQkI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=UjmXwElNrX3APZwE+ZgyUAhxLBDsHTPsCs7IS8ph9gmTSZOvyt1JdSeSgDgtBp4aqU7oQVOiJFfYHa3pNYvLfClCwp3+3crCtHzbb4nI8FNS3fcrRZ9xHhHMhmN5YCDMs9/A5AHANMXfpSbjRSHbykrnf7BACOG063q/aF/v5eQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=L64pt6UM; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="L64pt6UM" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1726060433; 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: in-reply-to:in-reply-to:references:references; bh=bVgk6KxCVvyf7/kqB/bzV5TeZ0PX9U997rsx8aaL5Jg=; b=L64pt6UMGdeRM5RFclFvleSRnImD2ZSqwFgr3/RKrgBM9Z4wHYeU06f7g3AYY6ozscINkj 8LuN/SM4lORi//X5qaOB3ZNXRE49p6R/3woZLeyljw1NMcSabHvshlQOlBqLsu4UYdiH2S qd7qNVK84yio22t4Bgtglz+cHefAsNU= Received: from mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (ec2-54-186-198-63.us-west-2.compute.amazonaws.com [54.186.198.63]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-217-hzJk0tqeP8eufD5z4fsd7w-1; Wed, 11 Sep 2024 09:13:48 -0400 X-MC-Unique: hzJk0tqeP8eufD5z4fsd7w-1 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 76DEA1956048; Wed, 11 Sep 2024 13:13:45 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.225.229]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 26E1119560A3; Wed, 11 Sep 2024 13:13:32 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 11 Sep 2024 15:13:34 +0200 (CEST) Date: Wed, 11 Sep 2024 15:13:20 +0200 From: Oleg Nesterov To: Sven Schnelle , Andrew Morton Cc: Michael Ellerman , Masami Hiramatsu , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , "Liang, Kan" , Linus Torvalds , Andrii Nakryiko , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Subject: [PATCH -mm 1/3] Revert "uprobes: use vm_special_mapping close() functionality" Message-ID: <20240911131320.GA3448@redhat.com> References: <20240903073629.2442754-1-svens@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20240903073629.2442754-1-svens@linux.ibm.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 This reverts commit 08e28de1160a712724268fd33d77b32f1bc84d1c. A malicious application can munmap() its "[uprobes]" vma and in this case xol_mapping.close == uprobe_clear_state() will free the memory which can be used by another thread, or the same thread when it hits the uprobe bp afterwards. Signed-off-by: Oleg Nesterov --- include/linux/uprobes.h | 1 + kernel/events/uprobes.c | 36 +++++++++++++++++++----------------- kernel/fork.c | 1 + 3 files changed, 21 insertions(+), 17 deletions(-) diff --git a/include/linux/uprobes.h b/include/linux/uprobes.h index 493dc95d912c..b503fafb7fb3 100644 --- a/include/linux/uprobes.h +++ b/include/linux/uprobes.h @@ -126,6 +126,7 @@ extern int uprobe_pre_sstep_notifier(struct pt_regs *regs); extern void uprobe_notify_resume(struct pt_regs *regs); extern bool uprobe_deny_signal(void); extern bool arch_uprobe_skip_sstep(struct arch_uprobe *aup, struct pt_regs *regs); +extern void uprobe_clear_state(struct mm_struct *mm); extern int arch_uprobe_analyze_insn(struct arch_uprobe *aup, struct mm_struct *mm, unsigned long addr); extern int arch_uprobe_pre_xol(struct arch_uprobe *aup, struct pt_regs *regs); extern int arch_uprobe_post_xol(struct arch_uprobe *aup, struct pt_regs *regs); diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index c2d6b2d64de2..73cc47708679 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -1482,22 +1482,6 @@ void * __weak arch_uprobe_trampoline(unsigned long *psize) return &insn; } -/* - * uprobe_clear_state - Free the area allocated for slots. - */ -static void uprobe_clear_state(const struct vm_special_mapping *sm, struct vm_area_struct *vma) -{ - struct xol_area *area = container_of(vma->vm_private_data, struct xol_area, xol_mapping); - - mutex_lock(&delayed_uprobe_lock); - delayed_uprobe_remove(NULL, vma->vm_mm); - mutex_unlock(&delayed_uprobe_lock); - - put_page(area->pages[0]); - kfree(area->bitmap); - kfree(area); -} - static struct xol_area *__create_xol_area(unsigned long vaddr) { struct mm_struct *mm = current->mm; @@ -1516,7 +1500,6 @@ static struct xol_area *__create_xol_area(unsigned long vaddr) area->xol_mapping.name = "[uprobes]"; area->xol_mapping.fault = NULL; - area->xol_mapping.close = uprobe_clear_state; area->xol_mapping.pages = area->pages; area->pages[0] = alloc_page(GFP_HIGHUSER); if (!area->pages[0]) @@ -1562,6 +1545,25 @@ static struct xol_area *get_xol_area(void) return area; } +/* + * uprobe_clear_state - Free the area allocated for slots. + */ +void uprobe_clear_state(struct mm_struct *mm) +{ + struct xol_area *area = mm->uprobes_state.xol_area; + + mutex_lock(&delayed_uprobe_lock); + delayed_uprobe_remove(NULL, mm); + mutex_unlock(&delayed_uprobe_lock); + + if (!area) + return; + + put_page(area->pages[0]); + kfree(area->bitmap); + kfree(area); +} + void uprobe_start_dup_mmap(void) { percpu_down_read(&dup_mmap_sem); diff --git a/kernel/fork.c b/kernel/fork.c index 61070248a7d3..3d590e51ce84 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1338,6 +1338,7 @@ static inline void __mmput(struct mm_struct *mm) { VM_BUG_ON(atomic_read(&mm->mm_users)); + uprobe_clear_state(mm); exit_aio(mm); ksm_exit(mm); khugepaged_exit(mm); /* must run before exit_mmap */ From patchwork Wed Sep 11 13:14:07 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oleg Nesterov X-Patchwork-Id: 13800514 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B50B91714AC for ; 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Wed, 11 Sep 2024 09:14:29 -0400 X-MC-Unique: UdEgacnvMGaY4T7ugj50_g-1 Received: from mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id A48B9197700E; Wed, 11 Sep 2024 13:14:26 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.225.229]) by mx-prod-int-01.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 85A893001D11; Wed, 11 Sep 2024 13:14:19 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 11 Sep 2024 15:14:15 +0200 (CEST) Date: Wed, 11 Sep 2024 15:14:07 +0200 From: Oleg Nesterov To: Sven Schnelle , Andrew Morton Cc: Michael Ellerman , Masami Hiramatsu , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , "Liang, Kan" , Linus Torvalds , Andrii Nakryiko , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Subject: [PATCH -mm 2/3] uprobes: introduce the global struct vm_special_mapping xol_mapping Message-ID: <20240911131407.GB3448@redhat.com> References: <20240903073629.2442754-1-svens@linux.ibm.com> <20240911131320.GA3448@redhat.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20240911131320.GA3448@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.4 Currently each xol_area has its own instance of vm_special_mapping, this is suboptimal and ugly. Kill xol_area->xol_mapping and add a single global instance of vm_special_mapping, the ->fault() method can use area->pages rather than xol_mapping->pages. As a side effect this fixes the problem introduced by the recent commit 223febc6e557 ("mm: add optional close() to struct vm_special_mapping"), if special_mapping_close() is called from the __mmput() paths, it will use vma->vm_private_data = &area->xol_mapping freed by uprobe_clear_state(). Reported-by: Sven Schnelle Closes: https://lore.kernel.org/all/yt9dy149vprr.fsf@linux.ibm.com/ Fixes: 223febc6e557 ("mm: add optional close() to struct vm_special_mapping") Signed-off-by: Oleg Nesterov --- kernel/events/uprobes.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index 73cc47708679..a478e028043f 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -99,7 +99,6 @@ struct xol_area { atomic_t slot_count; /* number of in-use slots */ unsigned long *bitmap; /* 0 = free slot */ - struct vm_special_mapping xol_mapping; struct page *pages[2]; /* * We keep the vma's vm_start rather than a pointer to the vma @@ -1433,6 +1432,21 @@ void uprobe_munmap(struct vm_area_struct *vma, unsigned long start, unsigned lon set_bit(MMF_RECALC_UPROBES, &vma->vm_mm->flags); } +static vm_fault_t xol_fault(const struct vm_special_mapping *sm, + struct vm_area_struct *vma, struct vm_fault *vmf) +{ + struct xol_area *area = vma->vm_mm->uprobes_state.xol_area; 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Wed, 11 Sep 2024 09:14:59 -0400 X-MC-Unique: A0mHO4ajN8u2MKgW2T49hg-1 Received: from mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.17]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 5DFD61955D45; Wed, 11 Sep 2024 13:14:56 +0000 (UTC) Received: from dhcp-27-174.brq.redhat.com (unknown [10.45.225.229]) by mx-prod-int-05.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 5477419560A3; Wed, 11 Sep 2024 13:14:49 +0000 (UTC) Received: by dhcp-27-174.brq.redhat.com (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Wed, 11 Sep 2024 15:14:44 +0200 (CEST) Date: Wed, 11 Sep 2024 15:14:37 +0200 From: Oleg Nesterov To: Sven Schnelle , Andrew Morton Cc: Michael Ellerman , Masami Hiramatsu , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim , Mark Rutland , Alexander Shishkin , Jiri Olsa , Ian Rogers , Adrian Hunter , "Liang, Kan" , Linus Torvalds , Andrii Nakryiko , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Subject: [PATCH -mm 3/3] uprobes: turn xol_area->pages[2] into xol_area->page Message-ID: <20240911131437.GC3448@redhat.com> References: <20240903073629.2442754-1-svens@linux.ibm.com> <20240911131320.GA3448@redhat.com> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20240911131320.GA3448@redhat.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Scanned-By: MIMEDefang 3.0 on 10.30.177.17 Now that xol_mapping has its own ->fault() method we no longer need xol_area->pages[1] == NULL, we need a single page. Signed-off-by: Oleg Nesterov --- kernel/events/uprobes.c | 17 ++++++++--------- 1 file changed, 8 insertions(+), 9 deletions(-) diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c index a478e028043f..94a17435cfe6 100644 --- a/kernel/events/uprobes.c +++ b/kernel/events/uprobes.c @@ -99,7 +99,7 @@ struct xol_area { atomic_t slot_count; /* number of in-use slots */ unsigned long *bitmap; /* 0 = free slot */ - struct page *pages[2]; + struct page *page; /* * We keep the vma's vm_start rather than a pointer to the vma * itself. The probed process or a naughty kernel module could make @@ -1437,7 +1437,7 @@ static vm_fault_t xol_fault(const struct vm_special_mapping *sm, { struct xol_area *area = vma->vm_mm->uprobes_state.xol_area; - vmf->page = area->pages[0]; + vmf->page = area->page; get_page(vmf->page); return 0; } @@ -1512,10 +1512,9 @@ static struct xol_area *__create_xol_area(unsigned long vaddr) if (!area->bitmap) goto free_area; - area->pages[0] = alloc_page(GFP_HIGHUSER); - if (!area->pages[0]) + area->page = alloc_page(GFP_HIGHUSER); + if (!area->page) goto free_bitmap; - area->pages[1] = NULL; area->vaddr = vaddr; init_waitqueue_head(&area->wq); @@ -1523,12 +1522,12 @@ static struct xol_area *__create_xol_area(unsigned long vaddr) set_bit(0, area->bitmap); atomic_set(&area->slot_count, 1); insns = arch_uprobe_trampoline(&insns_size); - arch_uprobe_copy_ixol(area->pages[0], 0, insns, insns_size); + arch_uprobe_copy_ixol(area->page, 0, insns, insns_size); if (!xol_add_vma(mm, area)) return area; - __free_page(area->pages[0]); + __free_page(area->page); free_bitmap: kfree(area->bitmap); free_area: @@ -1570,7 +1569,7 @@ void uprobe_clear_state(struct mm_struct *mm) if (!area) return; - put_page(area->pages[0]); + put_page(area->page); kfree(area->bitmap); kfree(area); } @@ -1637,7 +1636,7 @@ static unsigned long xol_get_insn_slot(struct uprobe *uprobe) if (unlikely(!xol_vaddr)) return 0; - arch_uprobe_copy_ixol(area->pages[0], xol_vaddr, + arch_uprobe_copy_ixol(area->page, xol_vaddr, &uprobe->arch.ixol, sizeof(uprobe->arch.ixol)); return xol_vaddr;