From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi2-f5.google.com (mail-oi2-f5.google.com [74.125.231.197]) (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 594BE3B7B7B for ; Wed, 16 Sep 2026 15:42:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.231.197 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789573360; cv=none; b=nGbfSUedg7Zgh1J7RoI2tKcW6IdBzAgxUH0PSwjU1QI63jfEJaT5OHdnBEp3V1JaTLjG7eeisLXMwlHjW9297HSuamIZhz8JcA+ADW36lAPuYE9IgyhI8kkb3RGOVVxBulRHH+NKvcpUywpzCjpU2r17z/mE3iypXocVI3RMX4Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789573360; c=relaxed/simple; bh=XtmNImX/5FFc4CPa3TkcFLuow3ei5FAnQFXOvKUJGgo=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=dAtQpyftg4AXoDjdPVIKR0edPPXpNfOceRVdR23y+LeEXHD/BfdedSvBu0j6/qRahJq8R06F65CL3Fkt90GdIBfX0w1gWWQvDbgJ3f0na+ACU39fhHACUvshlc/yp5mPRbEPBoox5G5zLbTNNs2KKnHe3Lg89aQid4LEK43bMLU= 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=74.125.231.197 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-oi2-f5.google.com with SMTP id 5614622812f47-4b3759b7ff0so3110077b6e.1 for ; Wed, 16 Sep 2026 08:42:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1789573352; x=1790178152; h=content-type:to:from:subject:message-id:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=S2Zr4D0P2DeY6uNjMgX/DVjNBdFFmJKnYEDUbNUQ4bU=; b=vxR8uJjBM29rXTsT0NdG2KzEpnjNWjjUW3cIUnK0qg5VCGk9MTP+VBkjl8ReRZ3elU qJMQ89ruHly3DcuMmYuVIpH6irzmMpyj39RTJPFlIykcHQwhxzSAeZy505wcDZZ6GolU q/v3SlEE5/1EXUzAJBDZErjAQOvKKgVerBjMkVsZuT/q2cM1mvmnxqyl7DDOf6knGN4n RFBr2pIcZRrur05/BlhvCi8h2ykIZc77CjiuEqW5bXDC4nC+BZcHWYAzmmYSL0mQHrLg qiFnMNVsbX/1IujbgZ8yJueebPkF09IerHrAKLHTLRKtYNNZzoGzx1tObnIITBxYxQpx Us4Q== X-Forwarded-Encrypted: i=1; AKwUvBzv8cDrza/JsoIGu2PzmrXVBJ3NRt1HTNxXXyIt1KmyCDa+5a7hJlrJx7ugH37/pQ/u0GMEqlJ+MGQuPWM=@vger.kernel.org X-Gm-Message-State: AFuF++l56By/MKdOll3c8HXjCVBXQpz1p91SJ1l9HhucH3o05WkXvu4+ kOnI0v3Vz44BOneK5xTw0N1Z7128im/muBHUurdys/sif1H2tGdp/b57TGc7fv4kxgB2k61z3J2 FNqRWcBb+0WCwSFcdRCDftGK6t8TV9tTV+o6fQUtUorGfi+oi5AkSLVZrkQc= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:30a9:b0:4c2:c244:72f9 with SMTP id 5614622812f47-4ca4bc74850mr4051592b6e.24.1789573352646; Wed, 16 Sep 2026 08:42:32 -0700 (PDT) Date: Wed, 16 Sep 2026 08:42:32 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6aaab8e8.bbedf9ee.1860ea.0004.GAE@google.com> Subject: [syzbot] [fs?] INFO: task hung in d_alloc_parallel (4) From: syzbot To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 704340f1cd0d Merge tag 'x86_urgent_for_7.3-rc4' of git://g.. git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=1585685e580000 kernel config: https://syzkaller.appspot.com/x/.config?x=b454dc6b1b7acd30 dashboard link: https://syzkaller.appspot.com/bug?extid=e8ebfecec06a009dd2d3 compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1385685e580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=144248c9580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/a1f812f889ad/disk-704340f1.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/8aa4ccae83ac/vmlinux-704340f1.xz kernel image: https://storage.googleapis.com/syzbot-assets/8f86a50bf181/bzImage-704340f1.xz mounted in repro: https://storage.googleapis.com/syzbot-assets/f097ea8b67eb/mount_0.gz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+e8ebfecec06a009dd2d3@syzkaller.appspotmail.com INFO: task syz-executor239:5636 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor239 state:D stack:28744 pid:5636 tgid:5633 ppid:5632 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x16d9/0x5700 kernel/sched/core.c:7277 __schedule_loop kernel/sched/core.c:7354 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7369 d_wait_lookup fs/dcache.c:2754 [inline] d_alloc_parallel+0xd13/0x16c0 fs/dcache.c:2839 __lookup_slow+0x82/0x2f0 fs/namei.c:1904 lookup_slow+0x53/0x70 fs/namei.c:1936 walk_component fs/namei.c:2282 [inline] link_path_walk+0xd2a/0x1910 fs/namei.c:2656 path_parentat fs/namei.c:2860 [inline] __filename_parentat+0x287/0x6f0 fs/namei.c:2884 filename_parentat fs/namei.c:2902 [inline] filename_create+0xd9/0x370 fs/namei.c:5073 filename_mkdirat+0xd2/0x520 fs/namei.c:5436 __do_sys_mkdirat fs/namei.c:5464 [inline] __se_sys_mkdirat+0x35/0x150 fs/namei.c:5461 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3765e43349 RSP: 002b:00007f3765def1d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007f3765eeae38 RCX: 00007f3765e43349 RDX: 00000000000001c0 RSI: 0000200000000640 RDI: 00000000ffffff9c RBP: 00007f3765eeae30 R08: 00007f3765def6c0 R09: 35203a6b63617473 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000640 R13: 0030656c69662f2e R14: 0000200000000280 R15: 0000200000000540 Showing all locks held in the system: locks held by khungtaskd/37: 1, last CPU#0: #0: ffffffff8e1c3c80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8e1c3c80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1c3c80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871 locks held by kworker/u8:7/1023: 2, on CPU#0: #0: ffff88813ff64138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffff88813ff64138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffff88813ff64138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #0: ffff88813ff64138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 #1: ffffc90005277c40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffc90005277c40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffc90005277c40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3361 [inline] #1: ffffc90005277c40 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x97a/0x1630 kernel/workqueue.c:3479 locks held by getty/5350: 2, on CPU#1: #0: ffff888036d190a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900044d62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 locks held by syz-executor239/5635: 1, last CPU#1: #0: ffff888045d8bda0 (&type->i_mutex_dir_key#6){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff888045d8bda0 (&type->i_mutex_dir_key#6){.+.+}-{4:4}, at: lookup_open+0x237/0x1a60 fs/namei.c:4460 locks held by syz-executor239/5636: 1, on CPU#0: #0: ffff888045d8bda0 (&type->i_mutex_dir_key#6){.+.+}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline] #0: ffff888045d8bda0 (&type->i_mutex_dir_key#6){.+.+}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1935 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/08/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:123 nmi_trigger_cpumask_backtrace+0x17d/0x390 lib/nmi_backtrace.c:66 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x38b/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5635 Comm: syz-executor239 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/08/2026 RIP: 0010:__might_sleep+0x31/0xf0 kernel/sched/core.c:9174 Code: 41 56 41 55 41 54 53 50 49 bf 00 00 00 00 00 fc ff df 65 48 8b 1d 87 17 0f 11 4c 8d 73 18 4c 89 f0 48 c1 e8 03 42 0f b6 04 38 <84> c0 0f 85 81 00 00 00 41 8b 2e 85 ed 74 2f 48 81 c3 90 18 00 00 RSP: 0018:ffffc90004c5f678 EFLAGS: 00000a02 RAX: 0000000000000000 RBX: ffff88801df83e80 RCX: ffff88801df83e80 RDX: 0000000000000000 RSI: 0000000000000142 RDI: ffffffff8d908f18 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff94000154819 R12: 0000000000000400 R13: 0000000000000400 R14: ffff88801df83e98 R15: dffffc0000000000 FS: 00007f3765e106c0(0000) GS:ffff888125ccb000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd25a71f52 CR3: 000000002ec1a000 CR4: 00000000003526f0 Call Trace: might_alloc include/linux/sched/mm.h:322 [inline] bdev_getblk+0xce/0x6e0 fs/buffer.c:1342 __bread_gfp+0x89/0x380 fs/buffer.c:1400 sb_bread include/linux/buffer_head.h:344 [inline] romfs_blk_strcmp fs/romfs/storage.c:175 [inline] romfs_dev_strcmp+0x3f8/0x790 fs/romfs/storage.c:284 romfs_lookup+0x232/0x3f0 fs/romfs/super.c:234 lookup_open+0x9eb/0x1a60 fs/namei.c:4528 open_last_lookups fs/namei.c:4767 [inline] path_openat+0x67c/0x1d60 fs/namei.c:4997 do_file_open+0x23e/0x4a0 fs/namei.c:5029 do_sys_openat2+0x115/0x200 fs/open.c:1417 do_sys_open fs/open.c:1423 [inline] __do_sys_openat fs/open.c:1439 [inline] __se_sys_openat fs/open.c:1434 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1434 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3765e43349 Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 d0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3765e101d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f3765eeae28 RCX: 00007f3765e43349 RDX: 0000000000000000 RSI: 0000200000000540 RDI: 00000000ffffff9c RBP: 00007f3765eeae20 R08: 35203a6b63617473 R09: 35203a6b63617473 R10: 0000000000000000 R11: 0000000000000246 R12: 0000200000000640 R13: 0030656c69662f2e R14: 0000200000000280 R15: 0000200000000540 --- 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. 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