From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=209.85.167.198 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793950541; b=arn8za2MrtlcnTQQlepnW0ka04HkCy9ouF+a12qsp/ll6llcMaw7EFlFLAPz7rZX3vir DmLsvkl7lzHK3ZCteSzzd993v+ZLMVevlSjnbAwUkoAi5QSKVAK5KzTCkH3RIoMpxQf8a wWzix1b2z9ocnrnbnuejhNsOnjbdrFJ3vdZ0XVl5hgljo0m8Mmhq+g79CB1rsq2hZK0Bx fb0X6jWmM36U1koDrYfRj41mJzsauTbi8XLLkw7zJkTwjjqTQqeyFnwmtVDaXzD6TeNZD n2f2yUIiSuZvHtHyIObFFJoITZf0qIOvikPOfiHPycbSPFTf3NUu608FyGCmJfUHo0A== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793950541; h=DMARC-Filter:Received:X-Google-DKIM-Signature:X-Forwarded-Encrypted: X-Gm-Message-State:MIME-Version:X-Received:Date: X-Google-Appengine-App-Id:X-Google-Appengine-App-Id-Alias:Message-ID: Subject:From:To:Content-Type; bh=i/988GRYLNIQ+m9ZryVFkUgt23XkOKZYFqEEbEyt0zM=; b=NeBY32D7pVnCAYtrG/hrByPEDTVjf3gY6razRhfUj66YgOlYKaT/PFCJ8SvMBaunBn5L 3KE8660YapJtlNY472Y3L8GAbys3BohFxK8oghV10cNRDCCcNdaT0BxuxwuVdzTlwe+St x6v1d2PzTdlwVHdhccDi+WP0Og8suHOKaFuc3/wSgR1rsy5xqy7UzsNpsjEloR+5jJXze OF8ErpijU6UT+mOCnGHrqKxi2UUjImyIwPOJIAXyitrt7UuMEZ9pxQXTrpY6xTZMd4Oxp 49XjR3cZCbNjVBgwEGs+IQ8IAg1icWwhDXG9+jZ5hXXWuD4UX05xREuGEc04xLnY9ig== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=fail header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.remote-ip=209.85.167.198 Received: from mail-oi1-f198.google.com (mail-oi1-f198.google.com [209.85.167.198]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6B342606A329 for ; Fri, 6 Nov 2026 07:35:41 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 6B342606A329 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-oi1-f198.google.com with SMTP id 5614622812f47-4a45b3f0bdfso492008b6e.1 for ; Thu, 05 Nov 2026 23:35:41 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1793950540; x=1794555340; 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=i/988GRYLNIQ+m9ZryVFkUgt23XkOKZYFqEEbEyt0zM=; b=lt7wYVsGuZ7ylf/r6W7XMNI3VurzphwdsdCCPNQWzzznBQdRKJaxilumab7Qp3pknW cSBk35I/4s7S5ky4T4ccr3GnRdQuOrO3TvFgisoCsyN20E6QDX09vLSFEGtWPUNMjC82 etRCcM/IxJv7sHM0tFCgtfJqZVWlY2520of5L0EzQZMYv8jb3yrwGAWJTRAFFg+QcS0b eRfjcVYsbPCoTyZW8J9B6h8rKgTxMEDAaJ99nowdxDO78rB1tI0ZeQtjHusodeRfPIu6 Q1nXhQxyWkxkdS+XyfOzxQft4shNx9+NbJIaxk8H7QUZw6WAvEe5LckIIrl9hSusX6H/ Zg5w== X-Forwarded-Encrypted: i=1; AKwUvBwFcLde8BKT6Hd2r+A/UmNaAIxilmQxfVLYriFr6ETQ2jSPnbfyPkYrzaMAzbjBh2pab/B8dzRa1p1XRew=@vger.kernel.org X-Gm-Message-State: APuU4Z9DUqbUpjKiD6ObZqLW757qu03O3Ef48T62L4cxUwsPpCQqqu/+ CTmeekxxvZLO4BdV7PPF3bOWRtqBThFyU0uxcEEcUUNbUVl2f1QFAnEGxMNi5Pi03CtMf24xrJ+ QZeLMSLq2oaSwks6hpi8sWNwyn7fzLYBwvTIL6qXIYUQmCbfQ9ouNinmmTOo= X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 X-Received: by 2002:a05:6808:120a:b0:4ab:230c:5faa with SMTP id 5614622812f47-567e14c930emr1056164b6e.18.1793950540289; Thu, 05 Nov 2026 23:35:40 -0800 (PST) Date: Thu, 05 Nov 2026 23:35:40 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6aed834c.dadc8e63.45095.0004.GAE@google.com> Subject: [syzbot] [nfs?] possible deadlock in nfsd_file_cache_shutdown From: syzbot To: Dai.Ngo@oracle.com, cel@kernel.org, jlayton@kernel.org, linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org, neil@brown.name, netdev@vger.kernel.org, okorniev@redhat.com, syzkaller-bugs@googlegroups.com, tom@talpey.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: c4ba1716853d net: atl1c: drop oversized RX frames instead .. git tree: net console output: https://syzkaller.appspot.com/x/log.txt?x=10dad4a1580000 kernel config: https://syzkaller.appspot.com/x/.config?x=d30e1495ee3ac817 dashboard link: https://syzkaller.appspot.com/bug?extid=e6bb7c8bc275dfed69c1 compiler: Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/1fbe24b1b049/disk-c4ba1716.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/4142b610b0c3/vmlinux-c4ba1716.xz kernel image: https://storage.googleapis.com/syzbot-assets/2441af2219d1/bzImage-c4ba1716.xz AI-generated root cause summary: In drivers/block/nbd.c, nbd_genl_reconnect_sock_cb() incorrectly calls sk_set_memalloc(sock->sk) while holding the mutex nsock->tx_lock. sk_set_memalloc() invokes static_branch_inc(), which acquires cpus_read_lock() (cpu_hotplug_lock). Because nsock->tx_lock is acquired during block I/O request dispatch in nbd_queue_rq(), it is part of the direct memory reclaim (fs_reclaim) dependency chain. Acquiring cpu_hotplug_lock under nsock->tx_lock inverts the core MM locking hierarchy (cpu_hotplug_lock -> slab_mutex -> fs_reclaim), creating an ABBA circular locking dependency that can lead to system deadlock. full analysis: https://syzkaller.appspot.com/x/ai_root_cause?x=e6bb7c8bc275dfed69c1 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+e6bb7c8bc275dfed69c1@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.4.1718/12980 is trying to acquire lock: ffffffff90094cc0 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:316 [inline] ffffffff90094cc0 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:4673 [inline] ffffffff90094cc0 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:5011 [inline] ffffffff90094cc0 (fs_reclaim){+.+.}-{0:0}, at: kmem_cache_alloc_noprof+0x5f/0x600 mm/slub.c:5047 but task is already holding lock: ffffffff900771b8 (slab_mutex){+.+.}-{4:4}, at: __kmem_cache_create_args+0x59/0x470 mm/slab_common.c:350 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #7 (slab_mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x197/0x15a0 kernel/locking/mutex.c:821 kmem_cache_destroy+0x73/0x180 mm/slab_common.c:565 nfsd_file_cache_shutdown+0x126/0x370 fs/nfsd/filecache.c:1063 nfsd_shutdown_generic fs/nfsd/nfssvc.c:293 [inline] nfsd_startup_net fs/nfsd/nfssvc.c:411 [inline] nfsd_svc+0x539/0x710 fs/nfsd/nfssvc.c:788 nfsd_nl_threads_set_doit+0xa6c/0xc30 fs/nfsd/nfsctl.c:1780 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2584 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x8ef/0xa80 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x7f0/0xb20 net/netlink/af_netlink.c:1920 sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800 __sock_sendmsg net/socket.c:818 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2715 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2769 __sys_sendmsg net/socket.c:2801 [inline] __do_sys_sendmsg net/socket.c:2806 [inline] __se_sys_sendmsg net/socket.c:2804 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2804 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 -> #6 (cpu_hotplug_lock){++++}-{0:0}: percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline] percpu_down_read include/linux/percpu-rwsem.h:77 [inline] cpus_read_lock+0x3d/0x160 kernel/cpu.c:490 static_key_slow_inc+0x12/0x30 kernel/jump_label.c:190 nbd_genl_reconnect_sock_cb+0x69a/0xbb0 drivers/block/nbd.c:1377 nbd_genl_foreach_sock+0x265/0x450 drivers/block/nbd.c:2152 nbd_genl_reconfigure+0xbbb/0x1040 drivers/block/nbd.c:2477 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2584 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x8ef/0xa80 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x7f0/0xb20 net/netlink/af_netlink.c:1920 sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800 __sock_sendmsg net/socket.c:818 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2715 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2769 __sys_sendmsg net/socket.c:2801 [inline] __do_sys_sendmsg net/socket.c:2806 [inline] __se_sys_sendmsg net/socket.c:2804 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2804 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 -> #5 (&nsock->tx_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x197/0x15a0 kernel/locking/mutex.c:821 nbd_handle_cmd drivers/block/nbd.c:1143 [inline] nbd_queue_rq+0x373/0xff0 drivers/block/nbd.c:1207 blk_mq_dispatch_rq_list+0x499/0x1990 block/blk-mq.c:2131 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline] __blk_mq_sched_dispatch_requests+0xd36/0x1580 block/blk-mq-sched.c:307 blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329 blk_mq_run_work_fn+0x167/0x2f0 block/blk-mq.c:2546 process_one_work kernel/workqueue.c:3495 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659 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 -> #4 (&cmd->lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x197/0x15a0 kernel/locking/mutex.c:821 nbd_queue_rq+0xc1/0xff0 drivers/block/nbd.c:1199 blk_mq_dispatch_rq_list+0x499/0x1990 block/blk-mq.c:2131 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline] blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline] __blk_mq_sched_dispatch_requests+0xd36/0x1580 block/blk-mq-sched.c:307 blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329 blk_mq_run_work_fn+0x167/0x2f0 block/blk-mq.c:2546 process_one_work kernel/workqueue.c:3495 [inline] process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659 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 -> #3 (set->srcu){.+.+}-{0:0}: srcu_lock_sync include/linux/srcu.h:225 [inline] __synchronize_srcu+0xca/0x2f0 kernel/rcu/srcutree.c:1662 elevator_switch+0x1e8/0x7b0 block/elevator.c:576 elevator_change+0x2fa/0x480 block/elevator.c:681 elevator_set_default+0x375/0x440 block/elevator.c:754 blk_register_queue+0x404/0x4f0 block/blk-sysfs.c:992 __add_disk+0x6b8/0xdb0 block/genhd.c:531 add_disk_fwnode+0x100/0x3a0 block/genhd.c:600 add_disk include/linux/blkdev.h:801 [inline] nbd_dev_add+0x733/0xb60 drivers/block/nbd.c:2026 nbd_init+0x168/0x1f0 drivers/block/nbd.c:2743 do_one_initcall+0x250/0x870 init/main.c:1419 do_initcall_level+0x10a/0x1a0 init/main.c:1481 do_initcalls+0x59/0xa0 init/main.c:1497 kernel_init_freeable+0x29d/0x3e0 init/main.c:1732 kernel_init+0x22/0x1d0 init/main.c:1622 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #2 (&q->elevator_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x197/0x15a0 kernel/locking/mutex.c:821 elevator_change+0x1af/0x480 block/elevator.c:679 elevator_set_none+0xb5/0x140 block/elevator.c:769 blk_mq_elv_switch_none block/blk-mq.c:5114 [inline] __blk_mq_update_nr_hw_queues block/blk-mq.c:5159 [inline] blk_mq_update_nr_hw_queues+0x5ef/0x19e0 block/blk-mq.c:5224 nbd_start_device+0x189/0xb30 drivers/block/nbd.c:1530 nbd_genl_connect+0x167d/0x1cd0 drivers/block/nbd.c:2310 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2584 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x8ef/0xa80 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x7f0/0xb20 net/netlink/af_netlink.c:1920 sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800 __sock_sendmsg net/socket.c:818 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2715 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2769 __sys_sendmsg net/socket.c:2801 [inline] __do_sys_sendmsg net/socket.c:2806 [inline] __se_sys_sendmsg net/socket.c:2804 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2804 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 -> #1 (&q->q_usage_counter(io)#49){++++}-{0:0}: blk_alloc_queue+0x544/0x690 block/blk-core.c:505 blk_mq_alloc_queue block/blk-mq.c:4439 [inline] __blk_mq_alloc_disk+0x194/0x390 block/blk-mq.c:4486 nbd_dev_add+0x494/0xb60 drivers/block/nbd.c:1996 nbd_init+0x168/0x1f0 drivers/block/nbd.c:2743 do_one_initcall+0x250/0x870 init/main.c:1419 do_initcall_level+0x10a/0x1a0 init/main.c:1481 do_initcalls+0x59/0xa0 init/main.c:1497 kernel_init_freeable+0x29d/0x3e0 init/main.c:1732 kernel_init+0x22/0x1d0 init/main.c:1622 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #0 (fs_reclaim){+.+.}-{0:0}: check_prev_add kernel/locking/lockdep.c:3209 [inline] check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 __fs_reclaim_acquire mm/page_alloc.c:4360 [inline] fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:4374 might_alloc include/linux/sched/mm.h:316 [inline] slab_pre_alloc_hook mm/slub.c:4673 [inline] slab_alloc_node mm/slub.c:5011 [inline] kmem_cache_alloc_noprof+0x5f/0x600 mm/slub.c:5047 create_cache mm/slab_common.c:249 [inline] __kmem_cache_create_args+0x30c/0x470 mm/slab_common.c:387 __kmem_cache_create include/linux/slab.h:402 [inline] ieee80211s_init net/mac80211/mesh.c:28 [inline] ieee80211_mesh_init_sdata+0x371/0x620 net/mac80211/mesh.c:1784 ieee80211_setup_sdata+0x858/0xc10 net/mac80211/iface.c:1980 ieee80211_if_change_type+0x141/0x940 net/mac80211/iface.c:2125 ieee80211_change_iface+0xdc/0x4b0 net/mac80211/cfg.c:275 rdev_change_virtual_intf net/wireless/rdev-ops.h:74 [inline] cfg80211_change_iface+0x40f/0x9c0 net/wireless/util.c:1368 nl80211_set_interface+0x78e/0xaa0 net/wireless/nl80211.c:5252 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2584 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x8ef/0xa80 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x7f0/0xb20 net/netlink/af_netlink.c:1920 sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800 __sock_sendmsg net/socket.c:818 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2715 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2769 __sys_sendmsg net/socket.c:2801 [inline] __do_sys_sendmsg net/socket.c:2806 [inline] __se_sys_sendmsg net/socket.c:2804 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2804 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 other info that might help us debug this: Chain exists of: fs_reclaim --> cpu_hotplug_lock --> slab_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(slab_mutex); lock(cpu_hotplug_lock); lock(slab_mutex); lock(fs_reclaim); *** DEADLOCK *** locks held by syz.4.1718/12980: 4, last CPU#0: #0: ffffffff914f05a8 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffffffff9148c2a0 (rtnl_mutex){+.+.}-{4:4}, at: nl80211_pre_doit+0x117/0xfa0 net/wireless/nl80211.c:20140 #2: ffff888067180800 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: wiphy_lock include/net/cfg80211.h:6974 [inline] #2: ffff888067180800 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: nl80211_pre_doit+0x6b2/0xfa0 net/wireless/nl80211.c:20189 #3: ffffffff900771b8 (slab_mutex){+.+.}-{4:4}, at: __kmem_cache_create_args+0x59/0x470 mm/slab_common.c:350 stack backtrace: CPU: 0 UID: 0 PID: 12980 Comm: syz.4.1718 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2087 check_noncircular+0x12f/0x150 kernel/locking/lockdep.c:2219 check_prev_add kernel/locking/lockdep.c:3209 [inline] check_prevs_add kernel/locking/lockdep.c:3328 [inline] validate_chain kernel/locking/lockdep.c:3952 [inline] __lock_acquire+0x164c/0x2de0 kernel/locking/lockdep.c:5288 lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5942 __fs_reclaim_acquire mm/page_alloc.c:4360 [inline] fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:4374 might_alloc include/linux/sched/mm.h:316 [inline] slab_pre_alloc_hook mm/slub.c:4673 [inline] slab_alloc_node mm/slub.c:5011 [inline] kmem_cache_alloc_noprof+0x5f/0x600 mm/slub.c:5047 create_cache mm/slab_common.c:249 [inline] __kmem_cache_create_args+0x30c/0x470 mm/slab_common.c:387 __kmem_cache_create include/linux/slab.h:402 [inline] ieee80211s_init net/mac80211/mesh.c:28 [inline] ieee80211_mesh_init_sdata+0x371/0x620 net/mac80211/mesh.c:1784 ieee80211_setup_sdata+0x858/0xc10 net/mac80211/iface.c:1980 ieee80211_if_change_type+0x141/0x940 net/mac80211/iface.c:2125 ieee80211_change_iface+0xdc/0x4b0 net/mac80211/cfg.c:275 rdev_change_virtual_intf net/wireless/rdev-ops.h:74 [inline] cfg80211_change_iface+0x40f/0x9c0 net/wireless/util.c:1368 nl80211_set_interface+0x78e/0xaa0 net/wireless/nl80211.c:5252 genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2584 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x8ef/0xa80 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x7f0/0xb20 net/netlink/af_netlink.c:1920 sock_sendmsg_nosec+0x14e/0x190 net/socket.c:800 __sock_sendmsg net/socket.c:818 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2715 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2769 __sys_sendmsg net/socket.c:2801 [inline] __do_sys_sendmsg net/socket.c:2806 [inline] __se_sys_sendmsg net/socket.c:2804 [inline] __x64_sys_sendmsg+0x1b1/0x290 net/socket.c:2804 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: 0033:0x7f0223f9fb19 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0224f20028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f0224226090 RCX: 00007f0223f9fb19 RDX: 0000000000000000 RSI: 0000200000000500 RDI: 0000000000000080 RBP: 00007f0224037b70 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0224226128 R14: 00007f0224226090 R15: 00007ffe4f069ef8 --- 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 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