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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 3AD01C433FE for ; Wed, 8 Sep 2021 16:52:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 207EF61157 for ; Wed, 8 Sep 2021 16:52:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352255AbhIHQxe (ORCPT ); Wed, 8 Sep 2021 12:53:34 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:53344 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350124AbhIHQxd (ORCPT ); Wed, 8 Sep 2021 12:53:33 -0400 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1631119942; 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=/5EPtDVyVzLxT15E52HQdw1eywPvZepjY6+SF1Ogzgk=; b=WcxcTwoxmq9agcrizLqac1Q7keJK6SWp57fGmeZoww4UbvCpmrxsWYuFabmTnQTvbGXObg t4FqAm0Nc+cpw+LR+DzWY3eyVXkhE2Tk7ixphk5KlqUkDAu1AQqoalewrI3HgWLE+0XIbf jei+lZftAL4SpdTpS8MewmZRmCvir6uvUvGIe6t6dUT64Y5+97UcTzkEKiT0LjzCNhoEhv c8H018SrOc2VEs1dTTIblipMsoaSxN8yJNJw/1XC15TEZva3Q8fJBlcyDDCC98nY3Ulc9s ZH2oEnI0gdHbuL4SahZmsJvWuws3eQ17bs0hHj0DA657Vc7Nlpci/FXdaSCcyQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1631119942; 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=/5EPtDVyVzLxT15E52HQdw1eywPvZepjY6+SF1Ogzgk=; b=2B6VKByQz39IlDUUv9z+gQtL86BeNWs2/Kih5bpCIwBAbv+6FHdwkG98ljTzogQdWrBG8Q DcC6W3q36IZ2biDQ== To: syzbot , linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Cc: Jens Axboe , io-uring@vger.kernel.org Subject: Re: [syzbot] BUG: unable to handle kernel paging request in timerqueue_del In-Reply-To: <0000000000009b05a305cb511b76@google.com> References: <0000000000009b05a305cb511b76@google.com> Date: Wed, 08 Sep 2021 18:52:22 +0200 Message-ID: <8735qff1rt.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Sep 06 2021 at 03:28, syzbot wrote: > HEAD commit: b91db6a0b52e Merge tag 'for-5.15/io_uring-vfs-2021-08-30' .. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=12a993fe300000 > kernel config: https://syzkaller.appspot.com/x/.config?x=210537ff2ddcc232 > dashboard link: https://syzkaller.appspot.com/bug?extid=89ee54915f0135ac38e0 > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1 > userspace arch: i386 > > Unfortunately, I don't have any reproducer for this issue yet. > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+89ee54915f0135ac38e0@syzkaller.appspotmail.com > > BUG: unable to handle page fault for address: ffffc9001bdbfd88 > #PF: supervisor read access in kernel mode > #PF: error_code(0x0000) - not-present page > PGD 10800067 P4D 10800067 PUD 109ba067 PMD 136067 PTE 0 > Oops: 0000 [#1] PREEMPT SMP KASAN > CPU: 0 PID: 19707 Comm: syz-executor.1 Not tainted 5.14.0-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > > RIP: 0010:__rb_change_child include/linux/rbtree_augmented.h:173 [inline] > RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:216 [inline] > RIP: 0010:rb_erase+0x5f6/0x1210 lib/rbtree.c:443 So the RB tree is corrupted. In the previous report io_uring clearly was using an uninitialized timer and in the console output of this one are clearly io uring commands. Obviously I can't tell for sure, but there is a pattern here. > Code: e3 fc 0f 84 0c 01 00 00 48 8d 7b 10 48 89 dd 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 84 0a 00 00 <4c> 3b 6b 10 0f 84 37 02 00 00 48 8d 7b 08 48 b8 00 00 00 00 00 fc > RSP: 0018:ffffc90000007d88 EFLAGS: 00010046 > RAX: dffffc0000000000 RBX: ffffc9001bdbfd78 RCX: 0000000000000000 > RDX: 1ffff920037b7fb1 RSI: ffff8880b9c424d0 RDI: ffffc9001bdbfd88 > RBP: ffffc9001bdbfd78 R08: ffffc9001bdbfd79 R09: 0000000000000001 > R10: ffffffff83f38fdc R11: 0000000000000000 R12: ffffc9001bdbfd79 > R13: ffffc9000256fd78 R14: ffffc9001aa2fd78 R15: ffff8880b9c424d0 > FS: 0000000000000000(0000) GS:ffff8880b9c00000(0063) knlGS:00000000f55b7b40 > CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 > CR2: ffffc9001bdbfd88 CR3: 000000008b5d9000 CR4: 00000000001506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > > rb_erase_cached include/linux/rbtree.h:126 [inline] > timerqueue_del+0x7f/0x140 lib/timerqueue.c:57 > __remove_hrtimer+0xa1/0x2a0 kernel/time/hrtimer.c:1116 > __run_hrtimer kernel/time/hrtimer.c:1665 [inline] > __hrtimer_run_queues+0x4ea/0xe50 kernel/time/hrtimer.c:1749 > hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 > local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] > __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 > sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 > > asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 > RIP: 0010:__sanitizer_cov_trace_const_cmp4+0xc/0x70 kernel/kcov.c:283 > Code: 00 00 00 48 89 7c 30 e8 48 89 4c 30 f0 4c 89 54 d8 20 48 89 10 5b c3 0f 1f 80 00 00 00 00 41 89 f8 bf 03 00 00 00 4c 8b 14 24 <89> f1 65 48 8b 34 25 40 f0 01 00 e8 54 f0 ff ff 84 c0 74 4b 48 8b > RSP: 0018:ffffc90019797440 EFLAGS: 00000246 > RAX: 0000000000000000 RBX: ffff8880001373e4 RCX: 0000000000000000 > RDX: 0000000000000003 RSI: 0000000000000004 RDI: 0000000000000003 > RBP: ffff8881407c547c R08: 0000000000000000 R09: ffffffff840a6804 > R10: ffffffff840a69c5 R11: 0000000000000008 R12: 0000000000000004 > R13: 0000000000000047 R14: ffff8880001373e0 R15: dffffc0000000000 > fast_imageblit drivers/video/fbdev/core/cfbimgblt.c:258 [inline] > cfb_imageblit+0x655/0x1240 drivers/video/fbdev/core/cfbimgblt.c:300 > vga_imageblit_expand drivers/video/fbdev/vga16fb.c:1207 [inline] > vga16fb_imageblit+0x681/0x2200 drivers/video/fbdev/vga16fb.c:1260 > bit_putcs_unaligned drivers/video/fbdev/core/bitblit.c:139 [inline] > bit_putcs+0x6e1/0xd20 drivers/video/fbdev/core/bitblit.c:188 > fbcon_putcs+0x35a/0x450 drivers/video/fbdev/core/fbcon.c:1296 > do_update_region+0x399/0x630 drivers/tty/vt/vt.c:676 > redraw_screen+0x61f/0x740 drivers/tty/vt/vt.c:1035 > vc_do_resize+0xe6f/0x1100 drivers/tty/vt/vt.c:1325 > fbcon_modechanged+0x393/0x6d0 drivers/video/fbdev/core/fbcon.c:2640 > fbcon_update_vcs+0x3a/0x50 drivers/video/fbdev/core/fbcon.c:2696 > do_fb_ioctl+0x62e/0x690 drivers/video/fbdev/core/fbmem.c:1108 > fb_compat_ioctl+0x17e/0x610 drivers/video/fbdev/core/fbmem.c:1307 > __do_compat_sys_ioctl+0x1c7/0x290 fs/ioctl.c:964 > do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline] > __do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178 > do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203 > entry_SYSENTER_compat_after_hwframe+0x4d/0x5c > RIP: 0023:0xf7fbd549 > Code: 03 74 c0 01 10 05 03 74 b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 > RSP: 002b:00000000f55b75fc EFLAGS: 00000296 ORIG_RAX: 0000000000000036 > RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000004601 > RDX: 0000000020000280 RSI: 0000000000000000 RDI: 0000000000000000 > RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > Modules linked in: > CR2: ffffc9001bdbfd88 > ---[ end trace 573584e01bd36498 ]--- > RIP: 0010:__rb_change_child include/linux/rbtree_augmented.h:173 [inline] > RIP: 0010:__rb_erase_augmented include/linux/rbtree_augmented.h:216 [inline] > RIP: 0010:rb_erase+0x5f6/0x1210 lib/rbtree.c:443 > Code: e3 fc 0f 84 0c 01 00 00 48 8d 7b 10 48 89 dd 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 84 0a 00 00 <4c> 3b 6b 10 0f 84 37 02 00 00 48 8d 7b 08 48 b8 00 00 00 00 00 fc > RSP: 0018:ffffc90000007d88 EFLAGS: 00010046 > RAX: dffffc0000000000 RBX: ffffc9001bdbfd78 RCX: 0000000000000000 > RDX: 1ffff920037b7fb1 RSI: ffff8880b9c424d0 RDI: ffffc9001bdbfd88 > RBP: ffffc9001bdbfd78 R08: ffffc9001bdbfd79 R09: 0000000000000001 > R10: ffffffff83f38fdc R11: 0000000000000000 R12: ffffc9001bdbfd79 > R13: ffffc9000256fd78 R14: ffffc9001aa2fd78 R15: ffff8880b9c424d0 > FS: 0000000000000000(0000) GS:ffff8880b9c00000(0063) knlGS:00000000f55b7b40 > CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 > CR2: ffffc9001bdbfd88 CR3: 000000008b5d9000 CR4: 00000000001506f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > ---------------- > Code disassembly (best guess): > 0: e3 fc jrcxz 0xfffffffe > 2: 0f 84 0c 01 00 00 je 0x114 > 8: 48 8d 7b 10 lea 0x10(%rbx),%rdi > c: 48 89 dd mov %rbx,%rbp > f: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax > 16: fc ff df > 19: 48 89 fa mov %rdi,%rdx > 1c: 48 c1 ea 03 shr $0x3,%rdx > 20: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) > 24: 0f 85 84 0a 00 00 jne 0xaae > * 2a: 4c 3b 6b 10 cmp 0x10(%rbx),%r13 <-- trapping instruction > 2e: 0f 84 37 02 00 00 je 0x26b > 34: 48 8d 7b 08 lea 0x8(%rbx),%rdi > 38: 48 rex.W > 39: b8 00 00 00 00 mov $0x0,%eax > 3e: 00 fc add %bh,%ah > > > --- > This report 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 issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.