From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oi1-f205.google.com (mail-oi1-f205.google.com [209.85.167.205]) (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 2B8D22FFF8D for ; Sat, 13 Jun 2026 04:22:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.205 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781324545; cv=none; b=WyIbseQlyYiweKIMah6UsalAmh+Lha1BQuJQ7dT05oBzAPjqeCz1ysoEZbsQhvT2LZNABvY0U0B3yCuVJ8eowouYctaqhsxrSa8WARGf71+lFYCkW0HJ2YHv8ofbg5zxDo5pTrtC2GDzExCkyhfM+HwCSD5NJaKwHqbG4zB2TwQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781324545; c=relaxed/simple; bh=X6mBMrisD7bBTU2sJNwZfIrBuSY/5WsgjruqjUY0rTI=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=opg2ikXd57IcI0/03Eauq/I8GQg3k5iq2lURJDnqruhHRrx7S3axoDfg4pDLsK9zLPUsPGifLLY8Jh5JbdPR0Kban/+fPs1VDI0496SKvU7oJRrtjGVzhjVy1wy/LbOrZZBCWc1IEaiM2kj5cVC/aD7b3TAfuSWH4PWQ8QRHgzI= 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=209.85.167.205 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-f205.google.com with SMTP id 5614622812f47-486cc29e03bso2674195b6e.3 for ; Fri, 12 Jun 2026 21:22:22 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1781324542; x=1781929342; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=647Piy0TDZ1tF6VoEaf+pcvbYAYZoWEajtL8BnsnRjQ=; b=CY0LHNMSdmA4EByr1u3Cr5y+7SbXMhHmXKOBPf6bzZ8L/k7hVEf4xoNL5grrdlIdoe NUKCtCV3DBuVNyqyRv2U76i+nnSzSrYgnz5VPqXb38V7nLJRfrgzCAHVQODRjVYLZglK sbSrP12Ez0jAS3FXr+UIlIZ+Bfmz5uQos0UQ1S9v/RT88as0dmgjbqz/107ADbKcmXiE 6q8B0nIL+TP0EYAdLwTDBWjZ6kaaVaAYXfC9qePHGbWlMgEL8H3WkR2Xa0Ipg19Eboo1 zGwDauLbcV5c4C/O9zpDb4OkHeejA1vqWKwETg9N6QI8KOvwOYJ77a8Ys+qC2vB3QhCd fwbg== X-Forwarded-Encrypted: i=1; AFNElJ94LAgMLUrrGyA4k0y8eeBDvc9/9Ceo9NKxjJl5n62utmFrdgts1NSxAGRAKnJdh0xNMHKQtOo=@vger.kernel.org X-Gm-Message-State: AOJu0YweJ2ekXeVxtw5/G/m/hv6OsCixTuHfbyXUCeHA2Ycz27LnC+Dt 6SzT2zK2dm+YBDAZMgwgYCybH/yNjwK0jllXaEF5ngvnhxNQMmcrnR3ICmzFVQMltVrV6Mvw2h3 K8RCqn3279lLXwaWKPLH09xDsAN4oPjEzvv6plRwno9kWHHlzTgfOflUc+mQ= Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6808:2511:b0:479:eb19:6e69 with SMTP id 5614622812f47-487419614eamr1787426b6e.6.1781324542218; Fri, 12 Jun 2026 21:22:22 -0700 (PDT) Date: Fri, 12 Jun 2026 21:22:22 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a2cdafe.428ffe26.258b27.0161.GAE@google.com> Subject: [syzbot] [net?] possible deadlock in udp_sendmsg (2) From: syzbot To: davem@davemloft.net, edumazet@google.com, horms@kernel.org, kuba@kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, pabeni@redhat.com, syzkaller-bugs@googlegroups.com, willemdebruijn.kernel@gmail.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 8b2feced65cd Merge branch 'net-dsa-microchip-remove-one-in.. git tree: net-next console output: https://syzkaller.appspot.com/x/log.txt?x=107db0c8580000 kernel config: https://syzkaller.appspot.com/x/.config?x=f2b487b72ffad035 dashboard link: https://syzkaller.appspot.com/bug?extid=607cdcf978b3e79da878 compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/25f12e68ab8d/disk-8b2feced.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/d8c43b4ea8e7/vmlinux-8b2feced.xz kernel image: https://storage.googleapis.com/syzbot-assets/e3d8f43606e0/bzImage-8b2feced.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+607cdcf978b3e79da878@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.4.8614/8291 is trying to acquire lock: ffffffff8ea85520 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:317 [inline] ffffffff8ea85520 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:4520 [inline] ffffffff8ea85520 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:4875 [inline] ffffffff8ea85520 (fs_reclaim){+.+.}-{0:0}, at: kmem_cache_alloc_node_noprof+0x4a/0x690 mm/slub.c:4950 but task is already holding lock: ffff88807c806860 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] ffff88807c806860 (sk_lock-AF_INET){+.+.}-{0:0}, at: udp_sendmsg+0x1747/0x21a0 net/ipv4/udp.c:1447 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #7 (sk_lock-AF_INET){+.+.}-{0:0}: lock_sock_nested+0x41/0x100 net/core/sock.c:3783 lock_sock include/net/sock.h:1713 [inline] tls_sw_sendmsg+0x15d/0x2430 net/tls/tls_sw.c:1291 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] sock_write_iter+0x406/0x4f0 net/socket.c:1254 do_iter_readv_writev+0x619/0x8c0 fs/read_write.c:-1 vfs_writev+0x33c/0x990 fs/read_write.c:1059 do_writev+0x154/0x2e0 fs/read_write.c:1105 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #6 (&ctx->tx_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a3/0x1550 kernel/locking/mutex.c:820 tls_sw_sendmsg+0x130/0x2430 net/tls/tls_sw.c:1288 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] sock_sendmsg+0x267/0x450 net/socket.c:825 __sock_xmit+0x251/0x510 drivers/block/nbd.c:576 sock_xmit drivers/block/nbd.c:605 [inline] send_disconnects drivers/block/nbd.c:1406 [inline] nbd_disconnect+0x3b7/0x560 drivers/block/nbd.c:1421 nbd_disconnect_and_put+0x37/0x2c0 drivers/block/nbd.c:2257 nbd_genl_disconnect+0x4a9/0x590 drivers/block/nbd.c:2303 genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2551 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1895 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752 __sys_sendmsg net/socket.c:2784 [inline] __do_sys_sendmsg net/socket.c:2789 [inline] __se_sys_sendmsg net/socket.c:2787 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #5 (&nsock->tx_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a3/0x1550 kernel/locking/mutex.c:820 nbd_handle_cmd drivers/block/nbd.c:1143 [inline] nbd_queue_rq+0x37b/0x1100 drivers/block/nbd.c:1207 blk_mq_dispatch_rq_list+0xa70/0x1910 block/blk-mq.c:2148 __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+0xdcc/0x1600 block/blk-mq-sched.c:307 blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329 blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2386 blk_mq_dispatch_list+0xd16/0xe10 include/linux/spinlock.h:-1 blk_mq_flush_plug_list+0x48d/0x570 block/blk-mq.c:2997 __blk_flush_plug+0x3ed/0x4d0 block/blk-core.c:1230 blk_finish_plug block/blk-core.c:1257 [inline] __submit_bio+0x28d/0x580 block/blk-core.c:649 __submit_bio_noacct_mq block/blk-core.c:722 [inline] submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:753 submit_bh fs/buffer.c:2742 [inline] block_read_full_folio+0x599/0x830 fs/buffer.c:2344 filemap_read_folio+0x137/0x3b0 mm/filemap.c:2502 do_read_cache_folio+0x358/0x590 mm/filemap.c:4107 read_mapping_folio include/linux/pagemap.h:1017 [inline] read_part_sector+0xb6/0x2b0 block/partitions/core.c:724 adfspart_check_ICS+0xb1/0x960 block/partitions/acorn.c:356 check_partition block/partitions/core.c:143 [inline] blk_add_partitions block/partitions/core.c:591 [inline] bdev_disk_changed+0x817/0x1770 block/partitions/core.c:695 blkdev_get_whole+0x380/0x510 block/bdev.c:756 bdev_open+0x31e/0xd30 block/bdev.c:965 blkdev_open+0x470/0x610 block/fops.c:697 do_dentry_open+0x785/0x14e0 fs/open.c:947 vfs_open+0x3b/0x340 fs/open.c:1079 do_open fs/namei.c:4699 [inline] path_openat+0x2e08/0x3860 fs/namei.c:4858 do_file_open+0x23e/0x4a0 fs/namei.c:4887 do_sys_openat2+0x113/0x200 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #4 (&cmd->lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:646 [inline] __mutex_lock+0x1a3/0x1550 kernel/locking/mutex.c:820 nbd_queue_rq+0xc6/0x1100 drivers/block/nbd.c:1199 blk_mq_dispatch_rq_list+0xa70/0x1910 block/blk-mq.c:2148 __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+0xdcc/0x1600 block/blk-mq-sched.c:307 blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329 blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2386 blk_mq_dispatch_list+0xd16/0xe10 include/linux/spinlock.h:-1 blk_mq_flush_plug_list+0x48d/0x570 block/blk-mq.c:2997 __blk_flush_plug+0x3ed/0x4d0 block/blk-core.c:1230 blk_finish_plug block/blk-core.c:1257 [inline] __submit_bio+0x28d/0x580 block/blk-core.c:649 __submit_bio_noacct_mq block/blk-core.c:722 [inline] submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:753 submit_bh fs/buffer.c:2742 [inline] block_read_full_folio+0x599/0x830 fs/buffer.c:2344 filemap_read_folio+0x137/0x3b0 mm/filemap.c:2502 do_read_cache_folio+0x358/0x590 mm/filemap.c:4107 read_mapping_folio include/linux/pagemap.h:1017 [inline] read_part_sector+0xb6/0x2b0 block/partitions/core.c:724 adfspart_check_ICS+0xb1/0x960 block/partitions/acorn.c:356 check_partition block/partitions/core.c:143 [inline] blk_add_partitions block/partitions/core.c:591 [inline] bdev_disk_changed+0x817/0x1770 block/partitions/core.c:695 blkdev_get_whole+0x380/0x510 block/bdev.c:756 bdev_open+0x31e/0xd30 block/bdev.c:965 blkdev_open+0x470/0x610 block/fops.c:697 do_dentry_open+0x785/0x14e0 fs/open.c:947 vfs_open+0x3b/0x340 fs/open.c:1079 do_open fs/namei.c:4699 [inline] path_openat+0x2e08/0x3860 fs/namei.c:4858 do_file_open+0x23e/0x4a0 fs/namei.c:4887 do_sys_openat2+0x113/0x200 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #3 (set->srcu){.+.+}-{0:0}: srcu_lock_sync include/linux/srcu.h:199 [inline] __synchronize_srcu+0xca/0x300 kernel/rcu/srcutree.c:1481 elevator_switch+0x1e8/0x7a0 block/elevator.c:576 elevator_change+0x2cc/0x450 block/elevator.c:681 elevator_set_default+0x36c/0x430 block/elevator.c:754 blk_register_queue+0x3e9/0x4e0 block/blk-sysfs.c:987 __add_disk+0x677/0xd50 block/genhd.c:528 add_disk_fwnode+0xfb/0x480 block/genhd.c:597 add_disk include/linux/blkdev.h:794 [inline] nbd_dev_add+0x72c/0xb50 drivers/block/nbd.c:1984 nbd_init+0x168/0x1f0 drivers/block/nbd.c:2692 do_one_initcall+0x250/0x870 init/main.c:1392 do_initcall_level+0x104/0x190 init/main.c:1454 do_initcalls+0x59/0xa0 init/main.c:1470 kernel_init_freeable+0x2a6/0x3e0 init/main.c:1703 kernel_init+0x1d/0x1d0 init/main.c:1593 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+0x1a3/0x1550 kernel/locking/mutex.c:820 elevator_change+0x1b3/0x450 block/elevator.c:679 elevator_set_none+0xb5/0x140 block/elevator.c:769 blk_mq_elv_switch_none block/blk-mq.c:5131 [inline] __blk_mq_update_nr_hw_queues block/blk-mq.c:5176 [inline] blk_mq_update_nr_hw_queues+0x5e7/0x1a60 block/blk-mq.c:5241 nbd_start_device+0x17f/0xb10 drivers/block/nbd.c:1489 nbd_genl_connect+0x165b/0x1cf0 drivers/block/nbd.c:2239 genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1114 genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline] genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1209 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2551 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1895 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752 __sys_sendmsg net/socket.c:2784 [inline] __do_sys_sendmsg net/socket.c:2789 [inline] __se_sys_sendmsg net/socket.c:2787 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&q->q_usage_counter(io)#53){++++}-{0:0}: blk_alloc_queue+0x546/0x680 block/blk-core.c:461 blk_mq_alloc_queue block/blk-mq.c:4450 [inline] __blk_mq_alloc_disk+0x197/0x390 block/blk-mq.c:4497 nbd_dev_add+0x499/0xb50 drivers/block/nbd.c:1954 nbd_init+0x168/0x1f0 drivers/block/nbd.c:2692 do_one_initcall+0x250/0x870 init/main.c:1392 do_initcall_level+0x104/0x190 init/main.c:1454 do_initcalls+0x59/0xa0 init/main.c:1470 kernel_init_freeable+0x2a6/0x3e0 init/main.c:1703 kernel_init+0x1d/0x1d0 init/main.c:1593 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:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __fs_reclaim_acquire mm/page_alloc.c:4325 [inline] fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:4339 might_alloc include/linux/sched/mm.h:317 [inline] slab_pre_alloc_hook mm/slub.c:4520 [inline] slab_alloc_node mm/slub.c:4875 [inline] kmem_cache_alloc_node_noprof+0x4a/0x690 mm/slub.c:4950 __alloc_skb+0x1d0/0x7d0 net/core/skbuff.c:702 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xc8/0x760 net/core/skbuff.c:6734 sock_alloc_send_pskb+0x878/0x990 net/core/sock.c:2998 sock_alloc_send_skb include/net/sock.h:1897 [inline] __ip_append_data+0x2a98/0x3e40 net/ipv4/ip_output.c:1127 ip_append_data+0x10d/0x190 net/ipv4/ip_output.c:1380 udp_sendmsg+0x3e4/0x21a0 net/ipv4/udp.c:1469 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] sock_sendmsg+0x379/0x450 net/socket.c:825 splice_to_socket+0xae2/0x11f0 fs/splice.c:884 do_splice_from fs/splice.c:936 [inline] do_splice+0xee3/0x1910 fs/splice.c:1349 __do_splice fs/splice.c:1431 [inline] __do_sys_splice fs/splice.c:1634 [inline] __se_sys_splice+0x353/0x490 fs/splice.c:1616 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: fs_reclaim --> &ctx->tx_lock --> sk_lock-AF_INET Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sk_lock-AF_INET); lock(&ctx->tx_lock); lock(sk_lock-AF_INET); lock(fs_reclaim); *** DEADLOCK *** 2 locks held by syz.4.8614/8291: #0: ffff888056734060 (&pipe->mutex){+.+.}-{4:4}, at: splice_to_socket+0x15f/0x11f0 fs/splice.c:805 #1: ffff88807c806860 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #1: ffff88807c806860 (sk_lock-AF_INET){+.+.}-{0:0}, at: udp_sendmsg+0x1747/0x21a0 net/ipv4/udp.c:1447 stack backtrace: CPU: 0 UID: 0 PID: 8291 Comm: syz.4.8614 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2043 check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175 check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x15a5/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868 __fs_reclaim_acquire mm/page_alloc.c:4325 [inline] fs_reclaim_acquire+0x71/0x100 mm/page_alloc.c:4339 might_alloc include/linux/sched/mm.h:317 [inline] slab_pre_alloc_hook mm/slub.c:4520 [inline] slab_alloc_node mm/slub.c:4875 [inline] kmem_cache_alloc_node_noprof+0x4a/0x690 mm/slub.c:4950 __alloc_skb+0x1d0/0x7d0 net/core/skbuff.c:702 alloc_skb include/linux/skbuff.h:1383 [inline] alloc_skb_with_frags+0xc8/0x760 net/core/skbuff.c:6734 sock_alloc_send_pskb+0x878/0x990 net/core/sock.c:2998 sock_alloc_send_skb include/net/sock.h:1897 [inline] __ip_append_data+0x2a98/0x3e40 net/ipv4/ip_output.c:1127 ip_append_data+0x10d/0x190 net/ipv4/ip_output.c:1380 udp_sendmsg+0x3e4/0x21a0 net/ipv4/udp.c:1469 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] sock_sendmsg+0x379/0x450 net/socket.c:825 splice_to_socket+0xae2/0x11f0 fs/splice.c:884 do_splice_from fs/splice.c:936 [inline] do_splice+0xee3/0x1910 fs/splice.c:1349 __do_splice fs/splice.c:1431 [inline] __do_sys_splice fs/splice.c:1634 [inline] __se_sys_splice+0x353/0x490 fs/splice.c:1616 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5eb159cdd9 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:00007f5eb24f7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00007f5eb1815fa0 RCX: 00007f5eb159cdd9 RDX: 000000000000000a RSI: 0000000000000000 RDI: 0000000000000008 RBP: 00007f5eb1632d69 R08: 002000000002ffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5eb1816038 R14: 00007f5eb1815fa0 R15: 00007ffe44aee038 --- 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