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 X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A1305C433E0 for ; Sat, 4 Jul 2020 16:45:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7CB2020723 for ; Sat, 4 Jul 2020 16:45:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593881127; bh=HGwVR1+Rt+My58aR0BObQ8X0y+JOyNAjSNB4lSDQEaU=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:List-ID: From; b=mXoY09Zvhua1KZHKtDTDyoCwGeB9CY4VGhDnc2VGWrfil/1VslHTpj2TQksUrjUlX 0fpbKAbfnLLDlmkWwp+iHJnpn35HtLS4zLOCJowRUiWLsh7kF/18Fw62ajTEu2+r8h +gBU/YPNgAenH7yZmVioEk7zPQ5DyDw2oCEOcAtQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726898AbgGDQpY (ORCPT ); Sat, 4 Jul 2020 12:45:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:60088 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726638AbgGDQpX (ORCPT ); Sat, 4 Jul 2020 12:45:23 -0400 Received: from paulmck-ThinkPad-P72.home (50-39-111-31.bvtn.or.frontiernet.net [50.39.111.31]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id C4FCA20723; Sat, 4 Jul 2020 16:45:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1593881122; bh=HGwVR1+Rt+My58aR0BObQ8X0y+JOyNAjSNB4lSDQEaU=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=tsuczAJRgNh3zSmLzZ0IS6vyP8dDcQdcJGycYdRd+3dfWTxICBITLcFSFTmrlZbu0 GqJvwimgd6OTUBtshS9C+90VDcnUsqjz3ReavYSe0jSR3Ejg0l2c9qdV2wBwB47Q0C DuIDkF7S1Hqd8liX0jV3xK2JbUQKylEKMECb+jKU= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id A3D2B352265B; Sat, 4 Jul 2020 09:45:22 -0700 (PDT) Date: Sat, 4 Jul 2020 09:45:22 -0700 From: "Paul E. McKenney" To: syzbot Cc: bigeasy@linutronix.de, linux-kernel@vger.kernel.org, mingo@kernel.org, peterz@infradead.org, syzkaller-bugs@googlegroups.com, tglx@linutronix.de Subject: Re: KASAN: stack-out-of-bounds Read in csd_lock_record Message-ID: <20200704164522.GO9247@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <00000000000042f21905a991ecea@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <00000000000042f21905a991ecea@google.com> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jul 03, 2020 at 04:31:22PM -0700, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 9e50b94b Add linux-next specific files for 20200703 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=1024b405100000 > kernel config: https://syzkaller.appspot.com/x/.config?x=f99cc0faa1476ed6 > dashboard link: https://syzkaller.appspot.com/bug?extid=0f719294463916a3fc0e > compiler: gcc (GCC) 10.1.0-syz 20200507 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16dc490f100000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+0f719294463916a3fc0e@syzkaller.appspotmail.com Good catch! A call to csd_lock_record() was on the wrong side of a call to csd_unlock(). But is folded into another commit for bisectability reasons, so "Reported-by" would not make sense. I have instead added this to the commit log: [ paulmck: Fix for syzbot+0f719294463916a3fc0e@syzkaller.appspotmail.com ] Link: https://lore.kernel.org/lkml/00000000000042f21905a991ecea@google.com Link: https://lore.kernel.org/lkml/0000000000002ef21705a9933cf3@google.com Thanx, Paul > ================================================================== > BUG: KASAN: stack-out-of-bounds in csd_lock_record+0xcb/0xe0 kernel/smp.c:118 > Read of size 8 at addr ffffc90001727710 by task syz-executor.0/10721 > > CPU: 1 PID: 10721 Comm: syz-executor.0 Not tainted 5.8.0-rc3-next-20200703-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Call Trace: > > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x18f/0x20d lib/dump_stack.c:118 > print_address_description.constprop.0.cold+0x5/0x436 mm/kasan/report.c:383 > __kasan_report mm/kasan/report.c:513 [inline] > kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 > csd_lock_record+0xcb/0xe0 kernel/smp.c:118 > flush_smp_call_function_queue+0x285/0x730 kernel/smp.c:391 > __sysvec_call_function_single+0x98/0x490 arch/x86/kernel/smp.c:248 > asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 > > __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] > run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] > sysvec_call_function_single+0xe0/0x120 arch/x86/kernel/smp.c:243 > asm_sysvec_call_function_single+0x12/0x20 arch/x86/include/asm/idtentry.h:604 > RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:765 [inline] > RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline] > RIP: 0010:_raw_spin_unlock_irqrestore+0x8c/0xe0 kernel/locking/spinlock.c:191 > Code: 48 c7 c0 00 ff b4 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 37 48 83 3d 9b 74 c8 01 00 74 22 48 89 df 57 9d <0f> 1f 44 00 00 bf 01 00 00 00 e8 95 fb 62 f9 65 8b 05 fe 73 15 78 > RSP: 0018:ffffc900016e7558 EFLAGS: 00000282 > RAX: 1ffffffff1369fe0 RBX: 0000000000000282 RCX: 0000000000000000 > RDX: dffffc0000000000 RSI: 0000000000000000 RDI: 0000000000000282 > RBP: ffffffff8cb02508 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000001 R11: 0000000000000000 R12: 1ffffffff19604a0 > R13: 0000000000000000 R14: dead000000000100 R15: dffffc0000000000 > __debug_check_no_obj_freed lib/debugobjects.c:977 [inline] > debug_check_no_obj_freed+0x20c/0x41c lib/debugobjects.c:998 > free_pages_prepare mm/page_alloc.c:1219 [inline] > __free_pages_ok+0x20b/0xc90 mm/page_alloc.c:1471 > release_pages+0x5ec/0x17a0 mm/swap.c:880 > tlb_batch_pages_flush mm/mmu_gather.c:49 [inline] > tlb_flush_mmu_free mm/mmu_gather.c:242 [inline] > tlb_flush_mmu+0xe9/0x6b0 mm/mmu_gather.c:249 > zap_pte_range mm/memory.c:1155 [inline] > zap_pmd_range mm/memory.c:1193 [inline] > zap_pud_range mm/memory.c:1222 [inline] > zap_p4d_range mm/memory.c:1243 [inline] > unmap_page_range+0x1e22/0x2b20 mm/memory.c:1264 > unmap_single_vma+0x198/0x300 mm/memory.c:1309 > unmap_vmas+0x16f/0x2f0 mm/memory.c:1341 > exit_mmap+0x2b1/0x530 mm/mmap.c:3165 > __mmput+0x122/0x470 kernel/fork.c:1075 > mmput+0x53/0x60 kernel/fork.c:1096 > exit_mm kernel/exit.c:483 [inline] > do_exit+0xa8f/0x2a40 kernel/exit.c:793 > do_group_exit+0x125/0x310 kernel/exit.c:904 > get_signal+0x40b/0x1ee0 kernel/signal.c:2743 > do_signal+0x82/0x2520 arch/x86/kernel/signal.c:810 > exit_to_usermode_loop arch/x86/entry/common.c:218 [inline] > __prepare_exit_to_usermode+0x156/0x1f0 arch/x86/entry/common.c:252 > do_syscall_64+0x6c/0xe0 arch/x86/entry/common.c:376 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > RIP: 0033:0x45cb29 > Code: Bad RIP value. > RSP: 002b:00007fb154b96cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca > RAX: 0000000000000001 RBX: 000000000078bf08 RCX: 000000000045cb29 > RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 000000000078bf0c > RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c > R13: 00007ffd3933f26f R14: 00007fb154b979c0 R15: 000000000078bf0c > > > Memory state around the buggy address: > ffffc90001727600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > ffffc90001727680: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00 > >ffffc90001727700: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 > ^ > ffffc90001727780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > ffffc90001727800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > ================================================================== > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches