From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f206.google.com (mail-il1-f206.google.com [209.85.166.206]) (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 8868134BA5F for ; Sun, 5 Oct 2025 00:02:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.206 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759622554; cv=none; b=QWp2ZCzHJZ4bIvJbNLmGwNK+C/uF92mv7GT78wwUtkoW/3GEXQOKw0JwrSm+TJRSYDKC80yl8BPF/K+v+6uVdMkvPu6cnpFW727Q6w2iSWqWWajUC22T5Mf7ajG09G7P+s0mjQQ5N8nhoOiP3NbqRg0g/FhHFKuSxbS8oG5ApOs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759622554; c=relaxed/simple; bh=lo63t1L+UB05neQU6bwjdC12nyKnjWsSyczwzCbQqv8=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=cn1UZMoZaRtDxx7bkRXVxk/1lKiWJ1JjTrGAz/43bqNzI/RqULSUwiTCg8otrJOnJtyvLJQwHkrE6JGXw/lNpxXOL5omIR+c8X8riuW9O9cP1ExVlX8q4RNl23UsolvXOcHG3rMAmILRJQi6k0IVexwoECC1li43Nek485IgnJ8= 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=209.85.166.206 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-il1-f206.google.com with SMTP id e9e14a558f8ab-42571c700d2so85728215ab.1 for ; Sat, 04 Oct 2025 17:02:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1759622551; x=1760227351; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=5gbSOXqFdQhFV7RV7nKtZmoWiQqVai1588UeQBrSxg8=; b=DOFN6HJx4eewlVMUVRuGMAYVZWs2yorD4U+f4KjDH/lkqw/6IFDZ21oK/OlLBpmuxa F00JEFecwrVecPmm/Xal9jHfJr1uFN7sxGMCFeqZzKbWm9S/9JOm1kmYIezqisdnWsmQ ZmvzHriG0wgK9jOVMyUaPzVjaPpgerwYVNpFyxm+iKQdpb6Snvb//wUue7tb0lhYeTmd 5ZBbhyN5FQmWIKUjGIyrOvNif/DJfaPMeuAD/J17OpxuimFoCXxI8rO+WvttcDxbljp7 EgIK9TG1Qnl9eeg7Cr24J6+T/OS3W4fhMq3Ld5gWivCL/Sno3L/svaTHjP2JT13WgKpj 9JJg== X-Forwarded-Encrypted: i=1; AJvYcCWd9a/iGw3lss5rVliXNIRjZSfzod9Sgg8N09MME7aFif2NdK8taZjdQ4b06TCtgGroA7XK8qI=@vger.kernel.org X-Gm-Message-State: AOJu0YyuY+XlhN99fVor1EsDTBK/BU/t8uNxgCsEp8poCLlIkbDlBAgJ R2dJVKtD7k+2P0MctJM++tW4949//xy5zeLM5sLl5GEwwydUFCHoK7YpoSILvvZC6/9FSMCGdOx y1YFX92Lr1bzqfPTrR7lWQ1BuOolMJj4V6rv043NrE4pbUna6rKbzhL3sPOk= X-Google-Smtp-Source: AGHT+IF4CfTlFlD8Q0XV5pDqo+m72N2N35dBC5nHoqAge+VTbTQ1Gl56yB1lQ8cHw9h9uLMiCDfmwI03T67Z6ZDYBxXmvbixDSI1 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:1885:b0:42d:84ec:b5e5 with SMTP id e9e14a558f8ab-42e7ad04f91mr111118535ab.3.1759622551648; Sat, 04 Oct 2025 17:02:31 -0700 (PDT) Date: Sat, 04 Oct 2025 17:02:31 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <68e1b597.a00a0220.102ee.0123.GAE@google.com> Subject: [syzbot] [net?] possible deadlock in tcp_sigpool_alloc_ahash From: syzbot To: davem@davemloft.net, dsahern@kernel.org, edumazet@google.com, horms@kernel.org, kuba@kernel.org, kuniyu@google.com, linux-kernel@vger.kernel.org, ncardwell@google.com, netdev@vger.kernel.org, pabeni@redhat.com, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 3b9b1f8df454 Add linux-next specific files for 20250929 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=15e88092580000 kernel config: https://syzkaller.appspot.com/x/.config?x=3c7c078c891391b1 dashboard link: https://syzkaller.appspot.com/bug?extid=6e6d72af97b9d4e47a40 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/1ccfc1a8eb22/disk-3b9b1f8d.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/c4e52fa84079/vmlinux-3b9b1f8d.xz kernel image: https://storage.googleapis.com/syzbot-assets/9eacf34feeec/bzImage-3b9b1f8d.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+6e6d72af97b9d4e47a40@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.4.3033/16107 is trying to acquire lock: ffffffff8fa52dc8 (cpool_mutex){+.+.}-{4:4}, at: tcp_sigpool_alloc_ahash+0x88/0xc70 net/ipv4/tcp_sigpool.c:162 but task is already holding lock: ffff888021793558 (sk_lock-AF_INET){+.+.}-{0:0}, at: do_tcp_setsockopt+0x854/0x1f20 net/ipv4/tcp.c:3928 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #7 (sk_lock-AF_INET){+.+.}-{0:0}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 lock_sock_nested+0x48/0x100 net/core/sock.c:3720 lock_sock include/net/sock.h:1679 [inline] inet_shutdown+0x6a/0x390 net/ipv4/af_inet.c:907 nbd_mark_nsock_dead+0x2e9/0x560 drivers/block/nbd.c:318 sock_shutdown+0x15e/0x260 drivers/block/nbd.c:411 nbd_clear_sock drivers/block/nbd.c:1424 [inline] nbd_config_put+0x342/0x790 drivers/block/nbd.c:1448 nbd_release+0xfe/0x140 drivers/block/nbd.c:1753 bdev_release+0x536/0x650 block/bdev.c:-1 blkdev_release+0x15/0x20 block/fops.c:702 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6b5/0x2300 kernel/exit.c:966 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0xa0/0x790 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x72/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #6 (&nsock->tx_lock){+.+.}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760 nbd_handle_cmd drivers/block/nbd.c:1140 [inline] nbd_queue_rq+0x257/0xf10 drivers/block/nbd.c:1204 blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2129 __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+0xda4/0x1570 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:2367 blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1 blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2976 __blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1225 blk_finish_plug block/blk-core.c:1252 [inline] __submit_bio+0x2d3/0x5a0 block/blk-core.c:651 __submit_bio_noacct_mq block/blk-core.c:724 [inline] submit_bio_noacct_nocheck+0x2fb/0xa50 block/blk-core.c:755 submit_bh fs/buffer.c:2829 [inline] block_read_full_folio+0x599/0x830 fs/buffer.c:2447 filemap_read_folio+0x117/0x380 mm/filemap.c:2444 do_read_cache_folio+0x350/0x590 mm/filemap.c:4024 read_mapping_folio include/linux/pagemap.h:999 [inline] read_part_sector+0xb6/0x2b0 block/partitions/core.c:722 adfspart_check_ICS+0xa4/0xa50 block/partitions/acorn.c:360 check_partition block/partitions/core.c:141 [inline] blk_add_partitions block/partitions/core.c:589 [inline] bdev_disk_changed+0x75f/0x14b0 block/partitions/core.c:693 blkdev_get_whole+0x380/0x510 block/bdev.c:748 bdev_open+0x31e/0xd30 block/bdev.c:957 blkdev_open+0x457/0x600 block/fops.c:694 do_dentry_open+0x953/0x13f0 fs/open.c:965 vfs_open+0x3b/0x340 fs/open.c:1097 do_open fs/namei.c:3975 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4134 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #5 (&cmd->lock){+.+.}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760 nbd_queue_rq+0xc8/0xf10 drivers/block/nbd.c:1196 blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2129 __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+0xda4/0x1570 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:2367 blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1 blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2976 __blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1225 blk_finish_plug block/blk-core.c:1252 [inline] __submit_bio+0x2d3/0x5a0 block/blk-core.c:651 __submit_bio_noacct_mq block/blk-core.c:724 [inline] submit_bio_noacct_nocheck+0x2fb/0xa50 block/blk-core.c:755 submit_bh fs/buffer.c:2829 [inline] block_read_full_folio+0x599/0x830 fs/buffer.c:2447 filemap_read_folio+0x117/0x380 mm/filemap.c:2444 do_read_cache_folio+0x350/0x590 mm/filemap.c:4024 read_mapping_folio include/linux/pagemap.h:999 [inline] read_part_sector+0xb6/0x2b0 block/partitions/core.c:722 adfspart_check_ICS+0xa4/0xa50 block/partitions/acorn.c:360 check_partition block/partitions/core.c:141 [inline] blk_add_partitions block/partitions/core.c:589 [inline] bdev_disk_changed+0x75f/0x14b0 block/partitions/core.c:693 blkdev_get_whole+0x380/0x510 block/bdev.c:748 bdev_open+0x31e/0xd30 block/bdev.c:957 blkdev_open+0x457/0x600 block/fops.c:694 do_dentry_open+0x953/0x13f0 fs/open.c:965 vfs_open+0x3b/0x340 fs/open.c:1097 do_open fs/namei.c:3975 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4134 do_filp_open+0x1fa/0x410 fs/namei.c:4161 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #4 (set->srcu){.+.+}-{0:0}: lock_sync+0xba/0x160 kernel/locking/lockdep.c:5916 srcu_lock_sync include/linux/srcu.h:173 [inline] __synchronize_srcu+0x96/0x3a0 kernel/rcu/srcutree.c:1439 elevator_switch+0x12b/0x640 block/elevator.c:588 elevator_change+0x315/0x4c0 block/elevator.c:691 elevator_set_default+0x186/0x260 block/elevator.c:767 blk_register_queue+0x34e/0x3f0 block/blk-sysfs.c:942 __add_disk+0x677/0xd50 block/genhd.c:528 add_disk_fwnode+0xfc/0x480 block/genhd.c:597 add_disk include/linux/blkdev.h:775 [inline] nbd_dev_add+0x717/0xae0 drivers/block/nbd.c:1981 nbd_init+0x168/0x1f0 drivers/block/nbd.c:2688 do_one_initcall+0x236/0x820 init/main.c:1283 do_initcall_level+0x104/0x190 init/main.c:1345 do_initcalls+0x59/0xa0 init/main.c:1361 kernel_init_freeable+0x334/0x4b0 init/main.c:1593 kernel_init+0x1d/0x1d0 init/main.c:1483 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #3 (&q->elevator_lock){+.+.}-{4:4}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760 elevator_change+0x1e5/0x4c0 block/elevator.c:689 elevator_set_none+0x42/0xb0 block/elevator.c:782 blk_mq_elv_switch_none block/blk-mq.c:5032 [inline] __blk_mq_update_nr_hw_queues block/blk-mq.c:5075 [inline] blk_mq_update_nr_hw_queues+0x598/0x1ab0 block/blk-mq.c:5133 nbd_start_device+0x17f/0xb10 drivers/block/nbd.c:1486 nbd_genl_connect+0x135b/0x18f0 drivers/block/nbd.c:2236 genl_family_rcv_msg_doit+0x215/0x300 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:714 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:729 ____sys_sendmsg+0x505/0x830 net/socket.c:2617 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2671 __sys_sendmsg net/socket.c:2703 [inline] __do_sys_sendmsg net/socket.c:2708 [inline] __se_sys_sendmsg net/socket.c:2706 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2706 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #2 (&q->q_usage_counter(io)#49){++++}-{0:0}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 blk_alloc_queue+0x538/0x620 block/blk-core.c:461 blk_mq_alloc_queue block/blk-mq.c:4399 [inline] __blk_mq_alloc_disk+0x15c/0x340 block/blk-mq.c:4446 nbd_dev_add+0x46c/0xae0 drivers/block/nbd.c:1951 nbd_init+0x168/0x1f0 drivers/block/nbd.c:2688 do_one_initcall+0x236/0x820 init/main.c:1283 do_initcall_level+0x104/0x190 init/main.c:1345 do_initcalls+0x59/0xa0 init/main.c:1361 kernel_init_freeable+0x334/0x4b0 init/main.c:1593 kernel_init+0x1d/0x1d0 init/main.c:1483 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 -> #1 (fs_reclaim){+.+.}-{0:0}: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __fs_reclaim_acquire mm/page_alloc.c:4269 [inline] fs_reclaim_acquire+0x72/0x100 mm/page_alloc.c:4283 might_alloc include/linux/sched/mm.h:318 [inline] slab_pre_alloc_hook mm/slub.c:4897 [inline] slab_alloc_node mm/slub.c:5221 [inline] __do_kmalloc_node mm/slub.c:5602 [inline] __kmalloc_noprof+0x9c/0x7f0 mm/slub.c:5615 kmalloc_noprof include/linux/slab.h:961 [inline] sigpool_reserve_scratch net/ipv4/tcp_sigpool.c:66 [inline] tcp_sigpool_alloc_ahash+0x144/0xc70 net/ipv4/tcp_sigpool.c:163 tcp_md5_alloc_sigpool+0x1b/0x50 net/ipv4/tcp.c:4824 tcp_md5_do_add+0x107/0x3a0 net/ipv4/tcp_ipv4.c:1428 tcp_v6_parse_md5_keys+0x4df/0x610 net/ipv6/tcp_ipv6.c:-1 do_tcp_setsockopt+0x11dc/0x1f20 net/ipv4/tcp.c:4059 do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2347 __sys_setsockopt net/socket.c:2372 [inline] __do_sys_setsockopt net/socket.c:2378 [inline] __se_sys_setsockopt net/socket.c:2375 [inline] __x64_sys_setsockopt+0x13f/0x1b0 net/socket.c:2375 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (cpool_mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3165 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760 tcp_sigpool_alloc_ahash+0x88/0xc70 net/ipv4/tcp_sigpool.c:162 tcp_md5_alloc_sigpool+0x1b/0x50 net/ipv4/tcp.c:4824 tcp_md5_do_add+0x107/0x3a0 net/ipv4/tcp_ipv4.c:1428 tcp_v4_parse_md5_keys+0x412/0x600 net/ipv4/tcp_ipv4.c:1577 do_tcp_setsockopt+0x11dc/0x1f20 net/ipv4/tcp.c:4059 do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2347 __sys_setsockopt net/socket.c:2372 [inline] __do_sys_setsockopt net/socket.c:2378 [inline] __se_sys_setsockopt net/socket.c:2375 [inline] __x64_sys_setsockopt+0x13f/0x1b0 net/socket.c:2375 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 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: cpool_mutex --> &nsock->tx_lock --> sk_lock-AF_INET Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(sk_lock-AF_INET); lock(&nsock->tx_lock); lock(sk_lock-AF_INET); lock(cpool_mutex); *** DEADLOCK *** 1 lock held by syz.4.3033/16107: #0: ffff888021793558 (sk_lock-AF_INET){+.+.}-{0:0}, at: do_tcp_setsockopt+0x854/0x1f20 net/ipv4/tcp.c:3928 stack backtrace: CPU: 0 UID: 0 PID: 16107 Comm: syz.4.3033 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043 check_noncircular+0x134/0x160 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+0xb9b/0x2140 kernel/locking/lockdep.c:3908 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __mutex_lock_common kernel/locking/mutex.c:598 [inline] __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760 tcp_sigpool_alloc_ahash+0x88/0xc70 net/ipv4/tcp_sigpool.c:162 tcp_md5_alloc_sigpool+0x1b/0x50 net/ipv4/tcp.c:4824 tcp_md5_do_add+0x107/0x3a0 net/ipv4/tcp_ipv4.c:1428 tcp_v4_parse_md5_keys+0x412/0x600 net/ipv4/tcp_ipv4.c:1577 do_tcp_setsockopt+0x11dc/0x1f20 net/ipv4/tcp.c:4059 do_sock_setsockopt+0x17c/0x1b0 net/socket.c:2347 __sys_setsockopt net/socket.c:2372 [inline] __do_sys_setsockopt net/socket.c:2378 [inline] __se_sys_setsockopt net/socket.c:2375 [inline] __x64_sys_setsockopt+0x13f/0x1b0 net/socket.c:2375 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe60a78eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fe60b545038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007fe60a9e5fa0 RCX: 00007fe60a78eec9 RDX: 000000000000000e RSI: 0000000000000006 RDI: 0000000000000004 RBP: 00007fe60a811f91 R08: 00000000000000d8 R09: 0000000000000000 R10: 0000200000000200 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe60a9e6038 R14: 00007fe60a9e5fa0 R15: 00007ffc33a46b58 --- 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