From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo2-f7.google.com (mail-oo2-f7.google.com [74.125.231.135]) (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 24BF44963B1 for ; Fri, 11 Sep 2026 15:47:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.231.135 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789141658; cv=none; b=NSAUvE02lu0hGfAE5AnGTdLahPAYJD4eSO9vSYW7bq/qzwzv/VerQNRmx0DixFgfNvtOUM2cNPRlb/vi0s/8q+S6RBUHfn279HxdwDXucad/OV5zNswk2ly2fEkPcZAK2FZMx0Vp2TKubi1hobCQ5jhCiS6+MFCTHdJmgDak+Kk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789141658; c=relaxed/simple; bh=qVLwnzFJuooHxJEhYdpgI0l0kT6jZR5zQ557mIWnQDM=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=sOyzIzjOHgZskK2hNKfhtzys4J/nEy+ImI5Ove8av/cMfzyR9egkTYCexK7d6kxHTnk5w/9gv/0h1vyH87pPwa/1v1gtyGzKw8rMuClQlh0u6UqUIEgt7Er4Xpsz9LGwZei8QrX1osFcKRKWgEnlWpR4GhEB0zikivNbUgQWlG0= 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=74.125.231.135 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-oo2-f7.google.com with SMTP id 006d021491bc7-6b1bebb3ae8so308641eaf.1 for ; Fri, 11 Sep 2026 08:47:35 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1789141655; x=1789746455; 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=QM9vuIsLaNesKNf1yNPCJMjrRtXbJZBFGQGVXa3DOY4=; b=BQtumexqtHYdldCznX9wex6AIZBKtmaxYrR1ggNtlwpe9s8lZ23aiU37ah+kQdfmLy rPU3pqQhHBs9HYY5K+8RQ7cQoJbIKczX3qi7GcoAQedrmRvCKZ0NxY8hMUf1j3qpsXTF RK975Ag0Y4ntZW+y6L/qz9/y0fHw36j+2EN2oE7AxLViCloXgtiq8QO2sJ9GQcEuNjH2 lZW0IIjwv5e8n83M4yqHBAE2k3jS31qmIJ0745j6H7OIwfvRcxrHOZSQqKOQQoTkxzYn SG0o7odDx8ztzBNGXgaaUOsPg4fwNod4GMWTLMnGm52jBQ2ckfh1XgkDDZVKC5TKuMqx 0t4Q== X-Forwarded-Encrypted: i=1; AKwUvBz6QrgHfMfXZVJsYdOHr1FDk4tQ1+YDiThMQ5JMwIIotqN6IaemHYIiN6UTnbxtu5CdIC9cLp/9qJ0PxuQ=@vger.kernel.org X-Gm-Message-State: AFuF++kXPjrlHpfbnHDEU6upljdmUlLa4TxP/Neb0DZPwk0M7itpty8q jR3SLYpULiZ3n+xfqYAHAfX5oJBFLVSt5XYqSgXTTcUx9VlGhayYdB/UuUd1oYsN/gBsjvjLRXW ISz++BPPHPhzn+QeKoQoGeCnTvCVb2c62eIvEKEfBOYuPgZbFOqBmUz+t7Xw= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:8582:20b0:6b1:9f9d:7a00 with SMTP id 006d021491bc7-6c0b9d512camr4916628eaf.5.1789141655109; Fri, 11 Sep 2026 08:47:35 -0700 (PDT) Date: Fri, 11 Sep 2026 08:47:35 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6aa42297.f2639fcc.29487d.002f.GAE@google.com> Subject: [syzbot] [kvm?] INFO: task hung in kvm_gmem_release (2) From: syzbot To: david@kernel.org, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, pbonzini@redhat.com, seanjc@google.com, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 50d05c7c76c9 Merge tag 'landlock-7.3-rc3' of git://git.ker.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=13db5ef9580000 kernel config: https://syzkaller.appspot.com/x/.config?x=5e4e3a0e188a497e dashboard link: https://syzkaller.appspot.com/bug?extid=ab6273c58262b9de56d9 compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 userspace arch: i386 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=143121f9580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/daf497619736/disk-50d05c7c.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/748fbd82f647/vmlinux-50d05c7c.xz kernel image: https://storage.googleapis.com/syzbot-assets/e61c59099d07/bzImage-50d05c7c.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+ab6273c58262b9de56d9@syzkaller.appspotmail.com INFO: task syz.0.17:5886 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:25512 pid:5886 tgid:5886 ppid:5771 task_flags:0x400040 flags:0x08080002 Call Trace: context_switch kernel/sched/core.c:5526 [inline] __schedule+0x17db/0x58f0 kernel/sched/core.c:7276 __schedule_loop kernel/sched/core.c:7353 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7368 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7425 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7c1/0x1550 kernel/locking/mutex.c:821 kvm_gmem_release+0xdf/0x3e0 virt/kvm/guest_memfd.c:310 __fput+0x418/0xa50 fs/file_table.c:512 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x204/0x770 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline] __do_fast_syscall_32+0x437/0x6a0 arch/x86/entry/syscall_32.c:294 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:316 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7f660ec RSP: 002b:00000000ff830cbc EFLAGS: 00000206 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 000000000000001e RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: locks held by khungtaskd/32: 1, last CPU#0: #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6871 locks held by getty/5374: 2, on CPU#1: #0: ffff88803555b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 locks held by syz.0.17/5886: 1, on CPU#1: #0: ffff8880597c00a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_gmem_release+0xdf/0x3e0 virt/kvm/guest_memfd.c:310 locks held by syz.0.17/5889: 1, last CPU#1: #0: ffff8880597c00a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_vm_set_mem_attributes virt/kvm/kvm_main.c:2566 [inline] #0: ffff8880597c00a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_vm_ioctl_set_mem_attributes+0x33c/0x1600 virt/kvm/kvm_main.c:2625 locks held by syz.1.20/5950: 1, on CPU#1: #0: ffff88807ea780a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_gmem_release+0xdf/0x3e0 virt/kvm/guest_memfd.c:310 locks held by syz.1.20/5952: 1, last CPU#1: #0: ffff88807ea780a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_vm_set_mem_attributes virt/kvm/kvm_main.c:2566 [inline] #0: ffff88807ea780a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_vm_ioctl_set_mem_attributes+0x33c/0x1600 virt/kvm/kvm_main.c:2625 locks held by syz.2.21/5991: 1, on CPU#0: #0: ffff8880291340a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_gmem_release+0xdf/0x3e0 virt/kvm/guest_memfd.c:310 locks held by syz.2.21/5993: 1, last CPU#0: #0: ffff8880291340a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_vm_set_mem_attributes virt/kvm/kvm_main.c:2566 [inline] #0: ffff8880291340a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_vm_ioctl_set_mem_attributes+0x33c/0x1600 virt/kvm/kvm_main.c:2625 locks held by syz.3.23/6034: 1, on CPU#1: #0: ffff88807b7ac0a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_gmem_release+0xdf/0x3e0 virt/kvm/guest_memfd.c:310 locks held by syz.3.23/6036: 1, last CPU#0: #0: ffff88807b7ac0a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_vm_set_mem_attributes virt/kvm/kvm_main.c:2566 [inline] #0: ffff88807b7ac0a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_vm_ioctl_set_mem_attributes+0x33c/0x1600 virt/kvm/kvm_main.c:2625 locks held by syz.4.24/6081: 1, on CPU#0: #0: ffff88807ea480a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_gmem_release+0xdf/0x3e0 virt/kvm/guest_memfd.c:310 locks held by syz.4.24/6083: 2, last CPU#1: #0: ffff88807ea480a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_vm_set_mem_attributes virt/kvm/kvm_main.c:2566 [inline] #0: ffff88807ea480a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_vm_ioctl_set_mem_attributes+0x33c/0x1600 virt/kvm/kvm_main.c:2625 #1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8ed5c8a0 (rcu_read_lock){....}-{1:3}, at: ieee80211_rx_napi+0xd1/0x3d0 net/mac80211/rx.c:5742 locks held by syz.5.27/6142: 1, on CPU#1: #0: ffff888072ba00a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_gmem_release+0xdf/0x3e0 virt/kvm/guest_memfd.c:310 locks held by syz.5.27/6144: 1, last CPU#0: #0: ffff888072ba00a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_vm_set_mem_attributes virt/kvm/kvm_main.c:2566 [inline] #0: ffff888072ba00a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_vm_ioctl_set_mem_attributes+0x33c/0x1600 virt/kvm/kvm_main.c:2625 locks held by syz.6.28/6190: 1, on CPU#1: #0: ffff88807090c0a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_gmem_release+0xdf/0x3e0 virt/kvm/guest_memfd.c:310 locks held by syz.6.28/6192: 1, last CPU#0: #0: ffff88807090c0a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_vm_set_mem_attributes virt/kvm/kvm_main.c:2566 [inline] #0: ffff88807090c0a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_vm_ioctl_set_mem_attributes+0x33c/0x1600 virt/kvm/kvm_main.c:2625 locks held by syz.7.29/6246: 1, on CPU#1: #0: ffff888032ad40a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_gmem_release+0xdf/0x3e0 virt/kvm/guest_memfd.c:310 locks held by syz.7.29/6248: 1, last CPU#1: #0: ffff888032ad40a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_vm_set_mem_attributes virt/kvm/kvm_main.c:2566 [inline] #0: ffff888032ad40a0 (&kvm->slots_lock){+.+.}-{4:4}, at: kvm_vm_ioctl_set_mem_attributes+0x33c/0x1600 virt/kvm/kvm_main.c:2625 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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/0x480 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: 6083 Comm: syz.4.24 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:__this_cpu_preempt_check+0x0/0x20 lib/smp_processor_id.c:63 Code: f5 48 8b 74 24 20 48 c7 c7 00 9b 6d 8c e8 88 ac 42 f5 e8 23 ab 4d f5 eb ae 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 89 fe 48 c7 c7 80 9a 6d 8c e9 0d ff ff ff cc cc cc RSP: 0018:ffffc90003d27460 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 8000000000000001 RDX: 0000000000000000 RSI: ffff88807ea4a3d0 RDI: ffffffff8e6fe7fc RBP: 00000000ffffffff R08: ffffc90003d2755f R09: 0000000000000000 R10: ffffc90003d27548 R11: fffff520007a4eac R12: 0000000000000246 R13: ffff8880314c5dc0 R14: ffff88807ea4a3d0 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888124dd2000(0063) knlGS:00000000f6834b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f71e8c10 CR3: 0000000073d5a000 CR4: 00000000003526f0 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline] lock_is_held_type+0xdf/0x150 kernel/locking/lockdep.c:6017 lock_is_held include/linux/lockdep.h:249 [inline] xa_entry include/linux/xarray.h:1227 [inline] xas_descend lib/xarray.c:208 [inline] xas_load+0x198/0x5a0 lib/xarray.c:246 __xa_cmpxchg_raw lib/xarray.c:1783 [inline] __xa_cmpxchg+0xc3/0x1f0 lib/xarray.c:1769 xa_cmpxchg include/linux/xarray.h:699 [inline] xa_reserve include/linux/xarray.h:1088 [inline] kvm_vm_set_mem_attributes virt/kvm/kvm_main.c:2577 [inline] kvm_vm_ioctl_set_mem_attributes+0x429/0x1600 virt/kvm/kvm_main.c:2625 kvm_vm_ioctl+0xb33/0xd30 virt/kvm/kvm_main.c:5356 kvm_vm_compat_ioctl+0x2b1/0x3a0 virt/kvm/kvm_main.c:5480 __do_compat_sys_ioctl fs/ioctl.c:695 [inline] __se_compat_sys_ioctl fs/ioctl.c:638 [inline] __ia32_compat_sys_ioctl+0x5ea/0x950 fs/ioctl.c:638 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x27a/0x6a0 arch/x86/entry/syscall_32.c:291 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:316 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf705f0ec Code: 90 85 d2 74 0a 89 ce 81 e6 ff 0f 00 00 89 32 85 c0 74 05 c1 e9 0c 89 08 31 c0 5e 5d c3 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 58 b8 RSP: 002b:00000000f683450c EFLAGS: 00000206 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 000000004020aed2 RDX: 0000000080000200 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 --- 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