From mboxrd@z Thu Jan 1 00:00:00 1970 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751238AbeAAK35 (ORCPT + 1 other); Mon, 1 Jan 2018 05:29:57 -0500 Received: from www381.your-server.de ([78.46.137.84]:51158 "EHLO www381.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751049AbeAAK34 (ORCPT ); Mon, 1 Jan 2018 05:29:56 -0500 Subject: Re: [alsa-devel] WARNING in snd_pcm_hw_param_first To: Takashi Iwai , syzbot Cc: linux-kernel@vger.kernel.org, alsa-devel@alsa-project.org, syzkaller-bugs@googlegroups.com, mingo@kernel.org References: <001a11444d0e6d62800561a84805@google.com> From: Lars-Peter Clausen Message-ID: Date: Mon, 1 Jan 2018 11:29:51 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Authenticated-Sender: lars@metafoo.de Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Return-Path: On 01/01/2018 10:03 AM, Takashi Iwai wrote: [...] >> CPU: 0 PID: 3502 Comm: syzkaller781065 Not tainted 4.15.0-rc5+ #154 >> Hardware name: Google Google Compute Engine/Google Compute Engine, >> BIOS Google 01/01/2011 >> Call Trace: >> __dump_stack lib/dump_stack.c:17 [inline] >> dump_stack+0x194/0x257 lib/dump_stack.c:53 >> panic+0x1e4/0x41c kernel/panic.c:183 >> __warn+0x1dc/0x200 kernel/panic.c:547 >> report_bug+0x211/0x2d0 lib/bug.c:184 >> fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178 >> fixup_bug arch/x86/kernel/traps.c:247 [inline] >> do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296 >> do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 >> invalid_op+0x22/0x40 arch/x86/entry/entry_64.S:1079 >> RIP: 0010:snd_pcm_hw_param_first+0x289/0x690 sound/core/pcm_lib.c:1635 >> RSP: 0018:ffff8801c013f1a0 EFLAGS: 00010293 >> RAX: ffff8801c03bc3c0 RBX: ffff8801bff08dc0 RCX: ffffffff841bee19 >> RDX: 0000000000000000 RSI: 00000000ffffffea RDI: ffffed0038027e28 >> RBP: ffff8801c013f1f0 R08: ffffed0038027d63 R09: ffff8801c013eb10 >> R10: 0000000000000001 R11: ffffed0038027d62 R12: 000000000000000d >> R13: 00000000ffffffea R14: 0000000000000005 R15: 0000000000002000 >> snd_pcm_hw_param_near.constprop.27+0x78d/0x9a0 sound/core/oss/pcm_oss.c:457 >> snd_pcm_oss_change_params+0x17d3/0x3720 sound/core/oss/pcm_oss.c:969 >> snd_pcm_oss_make_ready+0xaa/0x130 sound/core/oss/pcm_oss.c:1128 >> snd_pcm_oss_sync+0x257/0x830 sound/core/oss/pcm_oss.c:1638 >> snd_pcm_oss_release+0x20b/0x280 sound/core/oss/pcm_oss.c:2431 >> __fput+0x327/0x7e0 fs/file_table.c:210 >> ____fput+0x15/0x20 fs/file_table.c:244 >> task_work_run+0x199/0x270 kernel/task_work.c:113 >> exit_task_work include/linux/task_work.h:22 [inline] >> do_exit+0x9bb/0x1ad0 kernel/exit.c:865 >> do_group_exit+0x149/0x400 kernel/exit.c:968 >> SYSC_exit_group kernel/exit.c:979 [inline] >> SyS_exit_group+0x1d/0x20 kernel/exit.c:977 >> do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline] >> do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389 >> entry_SYSENTER_compat+0x54/0x63 arch/x86/entry/entry_64_compat.S:129 >> RIP: 0023:0xf7f4ec79 >> RSP: 002b:00000000ffc2c18c EFLAGS: 00000292 ORIG_RAX: 00000000000000fc >> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000080f0298 >> RDX: 0000000000000000 RSI: 00000000080d9b78 RDI: 00000000080f02a0 >> RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 >> R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 >> R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 >> Dumping ftrace buffer: >> (ftrace buffer empty) >> Kernel Offset: disabled >> Rebooting in 86400 seconds.. > > This must be a superfluous WARN_ON() call invoked by snd_BUG_ON() > check that can be safely ignored. A quick fix patch is below. I believe those snd_BUG_ON() are there because these calls to refine should never fail based on the checks done earlier. And them triggering indicates that something is wrong somewhere else.