From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mout01.posteo.de (mout01.posteo.de [185.67.36.65]) (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 AFA4B1D514B for ; Wed, 9 Apr 2025 16:09:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.67.36.65 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744214988; cv=none; b=NjXBZV3i4TVM4i6yff9ZAcHfPKdlwFAS/T4AXnusACuiGuza6x25PvxZpa69pNlntdQ+vm1ZPbjkwOC+EjQ0AqMPijASOdXdy6sBj0qiVCLz7seq0O4IOImkf/w9tY6wFTcz7VJyqhXKto+bEZlo9GS8mwgmrnBOPXTLHes/b5c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1744214988; c=relaxed/simple; bh=YAIk8YC+InUQBAT/tdz5r5BfPfHq2GwlGqV0TbjAmQI=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; 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t=1744214983; bh=YAIk8YC+InUQBAT/tdz5r5BfPfHq2GwlGqV0TbjAmQI=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type: From; b=IFbtFwS790K5tuYYjRPD44RA9AmXRc51puUH/B63xn1+ej/vMAvmcRJd6Fk3lDraC MiFf1DFCsDX6wq1Of0XeqKAseg0JeHneqLQ/VmGJEzpMOqMIgTYollfFB4gOBKbM0C CLGqJhwbk+sBdBtyxblEvaEHVcHP6q3tJUblQhmbPvIukuWFw73lMKCd1KycIhLeV6 AjQSKdIYYm7g9omb+1DlKdKeNAmR/y7hKl1Xc5g9PuN9b6jBbOtjF/ksl2wRvQuTd7 BS7JK0asIx+OX+NiI+B4guL8ock3jcbLrooV3BhjUG+Hoh7wwtXfbN9gJRvDA0pgwH Qv3VJSKKCWkSg== Received: from customer (localhost [127.0.0.1]) by submission (posteo.de) with ESMTPSA id 4ZXnvp2VqPz9rxG; Wed, 9 Apr 2025 18:09:42 +0200 (CEST) From: Charalampos Mitrodimas To: syzbot Cc: kent.overstreet@linux.dev, linux-bcachefs@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [bcachefs?] WARNING in bch2_dev_free In-Reply-To: <67f50e3e.050a0220.396535.0560.GAE@google.com> (syzbot's message of "Tue, 08 Apr 2025 04:53:34 -0700") References: <67f50e3e.050a0220.396535.0560.GAE@google.com> Date: Wed, 09 Apr 2025 16:09:41 +0000 Message-ID: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain syzbot writes: > Hello, > > syzbot found the following issue on: > > HEAD commit: a4cda136f021 Add linux-next specific files for 20250404 > git tree: linux-next > console+strace: https://syzkaller.appspot.com/x/log.txt?x=12c3db4c580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=8a257c454bb1afb7 > dashboard link: https://syzkaller.appspot.com/bug?extid=aec9606169fbc3a12ca6 > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17ca0c04580000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11c3db4c580000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/59048bc9c206/disk-a4cda136.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/ad2ba7306f20/vmlinux-a4cda136.xz > kernel image: https://storage.googleapis.com/syzbot-assets/b3bef7acbf10/bzImage-a4cda136.xz > mounted in repro: https://storage.googleapis.com/syzbot-assets/110624be1513/mount_0.gz > > The issue was bisected to: > > commit dcffc3b1ae3251d796a25c673f614e3099ca83d3 > Author: Kent Overstreet > Date: Sun Mar 30 03:11:08 2025 +0000 > > bcachefs: Split up bch_dev.io_ref > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13948c04580000 > final oops: https://syzkaller.appspot.com/x/report.txt?x=10548c04580000 > console output: https://syzkaller.appspot.com/x/log.txt?x=17948c04580000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+aec9606169fbc3a12ca6@syzkaller.appspotmail.com > Fixes: dcffc3b1ae32 ("bcachefs: Split up bch_dev.io_ref") > > bcachefs (loop0): shutting down > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 5844 at fs/bcachefs/super.c:1229 bch2_dev_free+0x228/0x290 fs/bcachefs/super.c:1229 > Modules linked in: > CPU: 0 UID: 0 PID: 5844 Comm: syz-executor121 Not tainted 6.14.0-next-20250404-syzkaller #0 PREEMPT(full) > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 > RIP: 0010:bch2_dev_free+0x228/0x290 fs/bcachefs/super.c:1229 > Code: ff e8 4c cf 74 00 4c 89 ef e8 44 cf 74 00 48 89 df 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d e9 ee 53 96 07 e8 59 e9 32 fd 90 <0f> 0b 90 e9 09 fe ff ff e8 4b e9 32 fd 90 0f 0b 90 e9 15 fe ff ff > RSP: 0018:ffffc9000406fb88 EFLAGS: 00010293 > RAX: ffffffff849073d7 RBX: ffff888035282000 RCX: ffff888034af9e00 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 > RBP: ffff8880352820c0 R08: ffffffff850552f7 R09: 0000000000000000 > R10: ffff888035282208 R11: ffffed1006a5044a R12: ffff888075e003f0 > R13: ffff8880352820b0 R14: ffff888075e00000 R15: ffff888075e007b2 > FS: 000055558bb20380(0000) GS:ffff888124f8f000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000000000045bdd0 CR3: 00000000122a0000 CR4: 00000000003526f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > > bch2_fs_free+0x2b0/0x400 fs/bcachefs/super.c:688 > deactivate_locked_super+0xc4/0x130 fs/super.c:473 > cleanup_mnt+0x422/0x4c0 fs/namespace.c:1435 > task_work_run+0x251/0x310 kernel/task_work.c:227 > ptrace_notify+0x2dc/0x390 kernel/signal.c:2520 > ptrace_report_syscall include/linux/ptrace.h:415 [inline] > ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline] > syscall_exit_work+0xc7/0x1d0 kernel/entry/common.c:173 > syscall_exit_to_user_mode_prepare kernel/entry/common.c:200 [inline] > __syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline] > syscall_exit_to_user_mode+0x24a/0x340 kernel/entry/common.c:218 > do_syscall_64+0x100/0x230 arch/x86/entry/syscall_64.c:100 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7f49b0cec447 > Code: 07 00 48 83 c4 08 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8 > RSP: 002b:00007ffd94723978 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6 > RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f49b0cec447 > RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd94723a30 > RBP: 00007ffd94723a30 R08: 0000000000000000 R09: 0000000000000000 > R10: 00000000ffffffff R11: 0000000000000206 R12: 00007ffd94724aa0 > R13: 000055558bb216c0 R14: 0000000000000001 R15: 431bde82d7b634db > > > > --- #syz test From: Charalampos Mitrodimas Subject: [PATCH] bcachefs: Fix WARN_ON in bch2_dev_free After splitting bch_dev.io_ref into separate READ and WRITE refs, we need to ensure both refs are properly stopped before freeing a device. Add bch2_dev_io_ref_stop(ca, WRITE) to bch2_fs_free() to prevent the WARNING in bch2_dev_free(). Reported-by: syzbot+aec9606169fbc3a12ca6@syzkaller.appspotmail.com Fixes: dcffc3b1ae32 ("bcachefs: Split up bch_dev.io_ref") Signed-off-by: Charalampos Mitrodimas --- fs/bcachefs/super.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/bcachefs/super.c b/fs/bcachefs/super.c index a58edde43bee..089b69b685d9 100644 --- a/fs/bcachefs/super.c +++ b/fs/bcachefs/super.c @@ -684,6 +684,7 @@ void bch2_fs_free(struct bch_fs *c) if (ca) { EBUG_ON(atomic_long_read(&ca->ref) != 1); bch2_dev_io_ref_stop(ca, READ); + bch2_dev_io_ref_stop(ca, WRITE); bch2_free_super(&ca->disk_sb); bch2_dev_free(ca); } -- 2.39.5