From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-io1-f77.google.com (mail-io1-f77.google.com [209.85.166.77]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0D7E82D3EEE for ; Mon, 18 Aug 2025 08:04:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.77 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755504273; cv=none; b=N9cZLay8t5HUVu9j7XxQfBsLvH+DHC7vdldBSncPxoEVb0mXO+pNLqFQPlJ3W46c2y1gkxO3jnPgjUL1+AqBgjmBK/wx6qrJ4+S/Q12T7J0kTn6svMaDGldxRkcChOePBUIYizU3QlPaRSH1G5HZ1iqorfO8KKz4QOhEWCu6jlI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755504273; c=relaxed/simple; bh=RHk19o0hxuJWW/AUjMGx3j6AyVeEotI75BaRvs/6usI=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=sWTjRvWr1WMDHvdJdDZd3cJRwaRYBDQCjNVfG03endK+G9I0vhfQPZhDAdPjwHvr4ps8xBUb+DvqFNri1RxC+qRNExJ7WRHHqTBJ+PCSV8fX/BQsSI3vaybklriXhTAn3SCxLeRGaVih9aGl1eSVw8JUSfTpikM2wstri5Gqd94= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.166.77 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-io1-f77.google.com with SMTP id ca18e2360f4ac-88432cbe110so426276939f.0 for ; Mon, 18 Aug 2025 01:04:31 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1755504271; x=1756109071; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=SXCnyKQ3Vm9M1IoDEuwjwfWaE/02hODwJqv40lVhlK0=; b=OAJ+/svbCMRd0DR3HFre2VLrf4wsteqgJjSDh5KGMF4KN9aTSsjg3lQyRMSGTM29Oi EbQvuA3kv4Y6NCTLU8tpRSquFhDlRfoqIzsAloCKVxXrkldRjmM1FLDCqTwqlNmDUxsX XCtf9ShaMmFNJw8zInqL3omAryK6Vdt8G9qfbwiZMyDFXdXSrIqxWRvOvuM0G4KaWfqM K8u8SwdJvS0ruEePr8wPjaeiI489nVat1/BqiclKllVAx7D37ZlvNBywhfXfE0YShbzV yezg607ngkC4NcR83C9rzS4CFlS4h1iqGitckUTf5Th5786xFSWDk2xRS4sx2C4nTF6q 61gA== X-Forwarded-Encrypted: i=1; AJvYcCVtw8JmOM3+46+6h/ju/Ga4In23M+vBauQPrttrosZ4kqfShxSTvXP/WDnpQ1sjL3yknVvsoXFxC8C5bB8=@vger.kernel.org X-Gm-Message-State: AOJu0YzrkEZ+ixRuNfMMygguU9/fsR6oiQqZyv1yY/qD4peFEegq/req fnAKaiwML7PpboarWdcLjGmXOZN/8urbSR4fHp0LuWAz7PSjWzahORGcQn9kny6RNJQ0ViidKTw PXreoX/BXPjgq8dXscdEsowQUE776v57tfEABwFYSqqchGWdPMMIcx8/bB44= X-Google-Smtp-Source: AGHT+IG3kt2iy1xjjQ4YX7zLb09k9beA7lbFy2HID79JSAPU010RsT/rmQ5oO/ogDnt62ofaqeiOBwbktkqzqJ3/+ro7iQksbLgp Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6602:15c7:b0:876:a8dc:96cc with SMTP id ca18e2360f4ac-8843e39e913mr1960591339f.6.1755504271041; Mon, 18 Aug 2025 01:04:31 -0700 (PDT) Date: Mon, 18 Aug 2025 01:04:31 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <68a2de8f.050a0220.e29e5.0097.GAE@google.com> Subject: [syzbot] [fs?] [mm?] INFO: task hung in v9fs_file_fsync From: syzbot To: akpm@linux-foundation.org, brauner@kernel.org, dvyukov@google.com, elver@google.com, glider@google.com, jack@suse.cz, kasan-dev@googlegroups.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, oleg@redhat.com, syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk, willy@infradead.org Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 038d61fd6422 Linux 6.16 git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=15f5a234580000 kernel config: https://syzkaller.appspot.com/x/.config?x=515ec0b49771bcd1 dashboard link: https://syzkaller.appspot.com/bug?extid=d1b5dace43896bc386c3 compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=158063a2580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1335d3a2580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/34e894532715/disk-038d61fd.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/b6a27a46b9dc/vmlinux-038d61fd.xz kernel image: https://storage.googleapis.com/syzbot-assets/f97a9c8d8216/bzImage-038d61fd.xz The issue was bisected to: commit aaec5a95d59615523db03dd53c2052f0a87beea7 Author: Oleg Nesterov Date: Thu Jan 2 14:07:15 2025 +0000 pipe_read: don't wake up the writer if the pipe is still full bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1498e3a2580000 final oops: https://syzkaller.appspot.com/x/report.txt?x=1698e3a2580000 console output: https://syzkaller.appspot.com/x/log.txt?x=1298e3a2580000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+d1b5dace43896bc386c3@syzkaller.appspotmail.com Fixes: aaec5a95d596 ("pipe_read: don't wake up the writer if the pipe is still full") INFO: task syz-executor224:5849 blocked for more than 143 seconds. Not tainted 6.16.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor224 state:D stack:22952 pid:5849 tgid:5849 ppid:5848 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16aa/0x4c90 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 io_schedule+0x81/0xe0 kernel/sched/core.c:7724 folio_wait_bit_common+0x6b0/0xb90 mm/filemap.c:1317 folio_wait_writeback+0xb0/0x100 mm/page-writeback.c:3126 __filemap_fdatawait_range+0x147/0x230 mm/filemap.c:539 file_write_and_wait_range+0x275/0x330 mm/filemap.c:798 v9fs_file_fsync+0xcf/0x1a0 fs/9p/vfs_file.c:418 generic_write_sync include/linux/fs.h:3031 [inline] netfs_file_write_iter+0x3d8/0x4a0 fs/netfs/buffered_write.c:494 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x54b/0xa90 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb29049bef9 RSP: 002b:00007ffeb3361588 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000200000000140 RCX: 00007fb29049bef9 RDX: 0000000000007fec RSI: 0000200000000300 RDI: 0000000000000007 RBP: 0030656c69662f2e R08: 0000000000000006 R09: 0000000000000006 R10: 0000000000000006 R11: 0000000000000246 R12: 0000200000000180 R13: 00007fb2904e504e R14: 0000000000000001 R15: 0000000000000001 Showing all locks held in the system: 2 locks held by kworker/u8:0/12: 1 lock held by khungtaskd/31: #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13f0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 2 locks held by kworker/u8:6/1337: #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc9000451fbc0 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000451fbc0 ((work_completion)(&rreq->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 2 locks held by getty/5596: #0: ffff88803095f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036cb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor224/5849: #0: ffff88807f8cc428 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3096 [inline] #0: ffff88807f8cc428 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:682 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.16.0-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: 53 de 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 ad 21 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8de07d80 EFLAGS: 000002c2 RAX: eefad1cde067ed00 RBX: ffffffff81976918 RCX: eefad1cde067ed00 RDX: 0000000000000001 RSI: ffffffff8d982fba RDI: ffffffff8be1ba40 RBP: ffffffff8de07ea8 R08: ffff8880b8632f5b R09: 1ffff110170c65eb R10: dffffc0000000000 R11: ffffed10170c65ec R12: ffffffff8fa0b3f0 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a50 FS: 0000000000000000(0000) GS:ffff888125c57000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055943a295660 CR3: 000000000df38000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:749 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423 rest_init+0x2de/0x300 init/main.c:745 start_kernel+0x47d/0x500 init/main.c:1102 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x147 --- 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. For information about bisection process see: https://goo.gl/tpsmEJ#bisection If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup