From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f205.google.com (mail-il1-f205.google.com [209.85.166.205]) (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 4FD5D44C7C for ; Thu, 1 May 2025 11:17:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.205 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746098254; cv=none; b=bKaSs3XMPqNBDpxUQqOmWUyniDQM990K7Cl2f4LXFWiWKHe2D4ED+SU1VEyMkgzjyhZ1Ouhbu9JlX8azP97yAauHjVE2ZCTkC7JIQ3oUufnwmidP3YK1LM38/5MbGpBXF8bctGh+QehsLgFallrc/avY+x/vGWiLISDeISYZiT4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746098254; c=relaxed/simple; bh=FXohX/ArdMkzKso12PRdvYXeBoN6y1WPW9ycV+f68qw=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=jopkAesXiGk2ndqc9bCBHPDGu1mJYl2JAyMCk50KrEN4dAjjk39UelEOZ8s+LpuBAtyaapkcKWb9XL3IMkd9V+6671iwd3OYJM+UiesM4VqBe9WlCzuwcm/noiEvcqkM0jT8c2d6t75sY2kbGA+jizqug1Zb/vXOXOvOlPCFMes= 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=209.85.166.205 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-il1-f205.google.com with SMTP id e9e14a558f8ab-3d961b98140so18047545ab.0 for ; Thu, 01 May 2025 04:17:31 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1746098250; x=1746703050; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=yic3hQCMhlizJGNLrVHXqVvz42qkVwajdriEOxWrJE0=; b=rQN6zLcCca3f9a9kwBU9GpgNqb20A5IrBXxL/wmtdnHqSOUnoJAdn+T75dRHNC0kbr hN/beww5oUFYYIn7MtZ+z++q83T6lAWFOyh0eDG/tVFEotgaqPMBby6j3D+ATPk0eOnq U71iN8EyDkxF/gYZAu/q2DO6T/sBlndnkDz5fnGxFBMuD6KhMdAQYXJSFOX/3gMZWNp2 SW+OXJCuvWiV+l+5IBAXFQwGraf59zEjw1W+6in7E6ZSboFAT3n2fNMz3Oh3qv91TfPf wxio1FbV5ftxrB8MCdYyQbCvpepWmi4y4833MVEeraO+Nx2RgRJX1qpF6l2A2IZYJbDd 47/w== X-Forwarded-Encrypted: i=1; AJvYcCU0OamlZXr8RQDfrl3ntaSnb8bCTmdnYjX72cMoD33w0lsfHkREbbS88hvCf1vKOwjGwAAt3N1AGE7hviA=@vger.kernel.org X-Gm-Message-State: AOJu0Yxafign6Q/uucBNXE55OB8QyJY/vVx22/5nRSuQDY2V4X8SYsrS eLSXTHZFJ67vdcltrZfahmE2MABHCn56l0KyX2diIT0Re9+wlH+z026Y4DsUAC8p4GqiewsnxPp mV/aOwgs+MeMJRL02Rf6drSdEFh2GkA44Ldrxxcrp3GnsgunG+zgzO08= X-Google-Smtp-Source: AGHT+IEgYrWA2Wmm0e7UkfIW4S/pFnefYS9GNq29ptouwY7E9Y3068+zX6Z8SiyJRHanRO/Vzz3JW5evgDBgk9CCnlwgkgFlXm7q Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:32c8:b0:3d9:34c7:7b76 with SMTP id e9e14a558f8ab-3d96771bbb3mr75945565ab.16.1746098250527; Thu, 01 May 2025 04:17:30 -0700 (PDT) Date: Thu, 01 May 2025 04:17:30 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6813584a.050a0220.3a872c.0012.GAE@google.com> Subject: [syzbot] [net?] WARNING: suspicious RCU usage in fib6_del (3) From: syzbot To: davem@davemloft.net, dsahern@kernel.org, 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 Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 7a13c14ee59d Merge tag 'for-6.15-rc4-tag' of git://git.ker.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=16e871b3980000 kernel config: https://syzkaller.appspot.com/x/.config?x=541aa584278da96c dashboard link: https://syzkaller.appspot.com/bug?extid=2d1f030088fa84f9d163 compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7feb34a89c2a/non_bootable_disk-7a13c14e.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/db407f64de23/vmlinux-7a13c14e.xz kernel image: https://storage.googleapis.com/syzbot-assets/a423a8694742/bzImage-7a13c14e.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+2d1f030088fa84f9d163@syzkaller.appspotmail.com bridge_slave_0: left allmulticast mode bridge_slave_0: left promiscuous mode bridge0: port 1(bridge_slave_0) entered disabled state ============================= WARNING: suspicious RCU usage 6.15.0-rc4-syzkaller-00051-g7a13c14ee59d #0 Not tainted ----------------------------- net/ipv6/ip6_fib.c:2023 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 6 locks held by kworker/u32:8/16847: #0: ffff88801c68d148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90003bd7d18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff9010e510 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffffffff901243a8 (rtnl_mutex){+.+.}-{4:4}, at: cleanup_net+0x50d/0xb30 net/core/net_namespace.c:644 #4: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #4: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #4: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0x3a/0x2d0 net/ipv6/ip6_fib.c:2263 #5: ffff88802b926830 (&tb->tb6_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #5: ffff88802b926830 (&tb->tb6_lock){+.-.}-{3:3}, at: __fib6_clean_all+0xeb/0x2d0 net/ipv6/ip6_fib.c:2267 stack backtrace: CPU: 3 UID: 0 PID: 16847 Comm: kworker/u32:8 Not tainted 6.15.0-rc4-syzkaller-00051-g7a13c14ee59d #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865 fib6_del+0xcf2/0x1770 net/ipv6/ip6_fib.c:2023 fib6_clean_node+0x424/0x5b0 net/ipv6/ip6_fib.c:2202 fib6_walk_continue+0x44f/0x8d0 net/ipv6/ip6_fib.c:2124 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2172 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2252 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2268 rt6_sync_down_dev net/ipv6/route.c:4951 [inline] rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:4956 addrconf_ifdown.isra.0+0x11d/0x1a90 net/ipv6/addrconf.c:3854 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3777 notifier_call_chain+0xb9/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline] call_netdevice_notifiers net/core/dev.c:2228 [inline] dev_close_many+0x319/0x630 net/core/dev.c:1731 unregister_netdevice_many_notify+0x578/0x26f0 net/core/dev.c:11952 cleanup_net+0x596/0xb30 net/core/net_namespace.c:649 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ============================= WARNING: suspicious RCU usage 6.15.0-rc4-syzkaller-00051-g7a13c14ee59d #0 Not tainted ----------------------------- net/ipv6/ip6_fib.c:2035 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 6 locks held by kworker/u32:8/16847: #0: ffff88801c68d148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90003bd7d18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff9010e510 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffffffff901243a8 (rtnl_mutex){+.+.}-{4:4}, at: cleanup_net+0x50d/0xb30 net/core/net_namespace.c:644 #4: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #4: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #4: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0x3a/0x2d0 net/ipv6/ip6_fib.c:2263 #5: ffff88802b926830 (&tb->tb6_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #5: ffff88802b926830 (&tb->tb6_lock){+.-.}-{3:3}, at: __fib6_clean_all+0xeb/0x2d0 net/ipv6/ip6_fib.c:2267 stack backtrace: CPU: 3 UID: 0 PID: 16847 Comm: kworker/u32:8 Not tainted 6.15.0-rc4-syzkaller-00051-g7a13c14ee59d #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865 fib6_del+0x2ef/0x1770 net/ipv6/ip6_fib.c:2035 fib6_clean_node+0x424/0x5b0 net/ipv6/ip6_fib.c:2202 fib6_walk_continue+0x44f/0x8d0 net/ipv6/ip6_fib.c:2124 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2172 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2252 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2268 rt6_sync_down_dev net/ipv6/route.c:4951 [inline] rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:4956 addrconf_ifdown.isra.0+0x11d/0x1a90 net/ipv6/addrconf.c:3854 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3777 notifier_call_chain+0xb9/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline] call_netdevice_notifiers net/core/dev.c:2228 [inline] dev_close_many+0x319/0x630 net/core/dev.c:1731 unregister_netdevice_many_notify+0x578/0x26f0 net/core/dev.c:11952 cleanup_net+0x596/0xb30 net/core/net_namespace.c:649 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ============================= WARNING: suspicious RCU usage 6.15.0-rc4-syzkaller-00051-g7a13c14ee59d #0 Not tainted ----------------------------- net/ipv6/ip6_fib.c:1921 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 6 locks held by kworker/u32:8/16847: #0: ffff88801c68d148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90003bd7d18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff9010e510 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffffffff901243a8 (rtnl_mutex){+.+.}-{4:4}, at: cleanup_net+0x50d/0xb30 net/core/net_namespace.c:644 #4: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #4: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #4: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0x3a/0x2d0 net/ipv6/ip6_fib.c:2263 #5: ffff88802b926830 (&tb->tb6_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #5: ffff88802b926830 (&tb->tb6_lock){+.-.}-{3:3}, at: __fib6_clean_all+0xeb/0x2d0 net/ipv6/ip6_fib.c:2267 stack backtrace: CPU: 3 UID: 0 PID: 16847 Comm: kworker/u32:8 Not tainted 6.15.0-rc4-syzkaller-00051-g7a13c14ee59d #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865 fib6_del_route net/ipv6/ip6_fib.c:1921 [inline] fib6_del+0x1084/0x1770 net/ipv6/ip6_fib.c:2040 fib6_clean_node+0x424/0x5b0 net/ipv6/ip6_fib.c:2202 fib6_walk_continue+0x44f/0x8d0 net/ipv6/ip6_fib.c:2124 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2172 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2252 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2268 rt6_sync_down_dev net/ipv6/route.c:4951 [inline] rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:4956 addrconf_ifdown.isra.0+0x11d/0x1a90 net/ipv6/addrconf.c:3854 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3777 notifier_call_chain+0xb9/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline] call_netdevice_notifiers net/core/dev.c:2228 [inline] dev_close_many+0x319/0x630 net/core/dev.c:1731 unregister_netdevice_many_notify+0x578/0x26f0 net/core/dev.c:11952 cleanup_net+0x596/0xb30 net/core/net_namespace.c:649 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ============================= WARNING: suspicious RCU usage 6.15.0-rc4-syzkaller-00051-g7a13c14ee59d #0 Not tainted ----------------------------- net/ipv6/ip6_fib.c:1930 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 6 locks held by kworker/u32:8/16847: #0: ffff88801c68d148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90003bd7d18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff9010e510 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffffffff901243a8 (rtnl_mutex){+.+.}-{4:4}, at: cleanup_net+0x50d/0xb30 net/core/net_namespace.c:644 #4: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #4: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #4: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0x3a/0x2d0 net/ipv6/ip6_fib.c:2263 #5: ffff88802b926830 (&tb->tb6_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #5: ffff88802b926830 (&tb->tb6_lock){+.-.}-{3:3}, at: __fib6_clean_all+0xeb/0x2d0 net/ipv6/ip6_fib.c:2267 stack backtrace: CPU: 3 UID: 0 PID: 16847 Comm: kworker/u32:8 Not tainted 6.15.0-rc4-syzkaller-00051-g7a13c14ee59d #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865 fib6_del_route net/ipv6/ip6_fib.c:1930 [inline] fib6_del+0xfef/0x1770 net/ipv6/ip6_fib.c:2040 fib6_clean_node+0x424/0x5b0 net/ipv6/ip6_fib.c:2202 fib6_walk_continue+0x44f/0x8d0 net/ipv6/ip6_fib.c:2124 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2172 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2252 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2268 rt6_sync_down_dev net/ipv6/route.c:4951 [inline] rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:4956 addrconf_ifdown.isra.0+0x11d/0x1a90 net/ipv6/addrconf.c:3854 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3777 notifier_call_chain+0xb9/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline] call_netdevice_notifiers net/core/dev.c:2228 [inline] dev_close_many+0x319/0x630 net/core/dev.c:1731 unregister_netdevice_many_notify+0x578/0x26f0 net/core/dev.c:11952 cleanup_net+0x596/0xb30 net/core/net_namespace.c:649 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ============================= WARNING: suspicious RCU usage 6.15.0-rc4-syzkaller-00051-g7a13c14ee59d #0 Not tainted ----------------------------- net/ipv6/ip6_fib.c:1975 suspicious rcu_dereference_protected() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 7 locks held by kworker/u32:8/16847: #0: ffff88801c68d148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213 #1: ffffc90003bd7d18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214 #2: ffffffff9010e510 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xc9/0xb30 net/core/net_namespace.c:608 #3: ffffffff901243a8 (rtnl_mutex){+.+.}-{4:4}, at: cleanup_net+0x50d/0xb30 net/core/net_namespace.c:644 #4: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #4: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #4: ffffffff8e3bf5c0 (rcu_read_lock){....}-{1:3}, at: __fib6_clean_all+0x3a/0x2d0 net/ipv6/ip6_fib.c:2263 #5: ffff88802b926830 (&tb->tb6_lock){+.-.}-{3:3}, at: spin_lock_bh include/linux/spinlock.h:356 [inline] #5: ffff88802b926830 (&tb->tb6_lock){+.-.}-{3:3}, at: __fib6_clean_all+0xeb/0x2d0 net/ipv6/ip6_fib.c:2267 #6: ffff888046504d38 (&net->ipv6.fib6_walker_lock){++..}-{3:3}, at: fib6_del_route net/ipv6/ip6_fib.c:1971 [inline] #6: ffff888046504d38 (&net->ipv6.fib6_walker_lock){++..}-{3:3}, at: fib6_del+0x880/0x1770 net/ipv6/ip6_fib.c:2040 stack backtrace: CPU: 3 UID: 0 PID: 16847 Comm: kworker/u32:8 Not tainted 6.15.0-rc4-syzkaller-00051-g7a13c14ee59d #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: netns cleanup_net Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6865 fib6_del_route net/ipv6/ip6_fib.c:1975 [inline] fib6_del+0x1281/0x1770 net/ipv6/ip6_fib.c:2040 fib6_clean_node+0x424/0x5b0 net/ipv6/ip6_fib.c:2202 fib6_walk_continue+0x44f/0x8d0 net/ipv6/ip6_fib.c:2124 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2172 fib6_clean_tree+0xd4/0x110 net/ipv6/ip6_fib.c:2252 __fib6_clean_all+0x107/0x2d0 net/ipv6/ip6_fib.c:2268 rt6_sync_down_dev net/ipv6/route.c:4951 [inline] rt6_disable_ip+0x2ec/0x990 net/ipv6/route.c:4956 addrconf_ifdown.isra.0+0x11d/0x1a90 net/ipv6/addrconf.c:3854 addrconf_notify+0x220/0x19e0 net/ipv6/addrconf.c:3777 notifier_call_chain+0xb9/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2176 call_netdevice_notifiers_extack net/core/dev.c:2214 [inline] call_netdevice_notifiers net/core/dev.c:2228 [inline] dev_close_many+0x319/0x630 net/core/dev.c:1731 unregister_netdevice_many_notify+0x578/0x26f0 net/core/dev.c:11952 cleanup_net+0x596/0xb30 net/core/net_namespace.c:649 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 bond0 (unregistering): (slave bond_slave_0): Releasing backup interface bond0 (unregistering): (slave bond_slave_1): Releasing backup interface bond0 (unregistering): Released all slaves hsr_slave_0: left promiscuous mode hsr_slave_1: left promiscuous mode batman_adv: batadv0: Interface deactivated: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_0 batman_adv: batadv0: Interface deactivated: batadv_slave_1 batman_adv: batadv0: Removing interface: batadv_slave_1 veth1_macvtap: left promiscuous mode veth0_macvtap: left promiscuous mode veth1_vlan: left promiscuous mode veth0_vlan: left promiscuous mode team0 (unregistering): Port device team_slave_1 removed team0 (unregistering): Port device team_slave_0 removed netdevsim netdevsim2 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim2 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim2 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim2 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim0 netdevsim3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim0 netdevsim2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim0 netdevsim1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim0 netdevsim0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim9 eth3 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim9 eth2 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim9 eth1 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 netdevsim netdevsim9 eth0 (unregistering): unset [1, 0] type 2 family 0 port 6081 - 0 bridge_slave_1: left allmulticast mode bridge_slave_1: left promiscuous mode bridge0: port 2(bridge_slave_1) entered disabled state bridge_slave_0: left allmulticast mode bridge_slave_0: left promiscuous mode bridge0: port 1(bridge_slave_0) entered disabled state bridge_slave_1: left allmulticast mode bridge_slave_1: left promiscuous mode bridge0: port 2(bridge_slave_1) entered disabled state bridge_slave_0: left allmulticast mode bridge_slave_0: left promiscuous mode bridge0: port 1(bridge_slave_0) entered disabled state bridge_slave_1: left allmulticast mode bridge_slave_1: left promiscuous mode bridge0: port 2(bridge_slave_1) entered disabled state bridge_slave_0: left allmulticast mode bridge_slave_0: left promiscuous mode bridge0: port 1(bridge_slave_0) entered disabled state bridge_slave_1: left allmulticast mode bridge_slave_1: left promiscuous mode bridge0: port 2(bridge_slave_1) entered disabled state bridge0: port 1(bridge_slave_0) entered disabled state bond0 (unregistering): (slave bond_slave_0): Releasing backup interface bond_slave_0: left allmulticast mode bond0 (unregistering): (slave bond_slave_1): Releasing backup interface bond_slave_1: left allmulticast mode bond0 (unregistering): Released all slaves bond1 (unregistering): Released all slaves bond2 (unregistering): Released all slaves bond0 (unregistering): (slave bond_slave_0): Releasing backup interface bond0 (unregistering): (slave bond_slave_1): Releasing backup interface bond0 (unregistering): Released all slaves bond0 (unregistering): left promiscuous mode bond_slave_0: left promiscuous mode bond_slave_1: left promiscuous mode bond0 (unregistering): (slave bond_slave_0): Releasing backup interface bond0 (unregistering): (slave bond_slave_1): Releasing backup interface bond0 (unregistering): Released all slaves bond0 (unregistering): (slave bond_slave_0): Releasing backup interface bond0 (unregistering): (slave bond_slave_1): Releasing backup interface bond0 (unregistering): Released all slaves bond1 (unregistering): (slave veth3): Releasing active interface bond1 (unregistering): Released all slaves bond2 (unregistering): Released all slaves IPVS: stopping master sync thread 17458 ... hsr_slave_0: left promiscuous mode hsr_slave_1: left promiscuous mode batman_adv: batadv0: Interface deactivated: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_0 batman_adv: batadv0: Interface deactivated: batadv_slave_1 batman_adv: batadv0: Removing interface: batadv_slave_1 hsr_slave_0: left promiscuous mode hsr_slave_1: left promiscuous mode batman_adv: batadv0: Removing interface: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_1 batadv0: left promiscuous mode hsr_slave_0: left promiscuous mode hsr_slave_1: left promiscuous mode batman_adv: batadv0: Interface deactivated: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_0 batman_adv: batadv0: Interface deactivated: batadv_slave_1 batman_adv: batadv0: Removing interface: batadv_slave_1 hsr_slave_0: left promiscuous mode hsr_slave_1: left promiscuous mode batman_adv: batadv0: Interface deactivated: batadv_slave_0 batman_adv: batadv0: Removing interface: batadv_slave_0 batman_adv: batadv0: Interface deactivated: batadv_slave_1 batman_adv: batadv0: Removing interface: batadv_slave_1 veth1_vlan: left promiscuous mode veth0_vlan: left promiscuous mode veth1_macvtap: left promiscuous mode veth0_macvtap: left promiscuous mode veth1_vlan: left promiscuous mode veth0_vlan: left promiscuous mode veth1_macvtap: left promiscuous mode veth0_macvtap: left promiscuous mode veth1_vlan: left promiscuous mode veth0_vlan: left promiscuous mode team0 (unregistering): Port device team_slave_1 removed team0 (unregistering): Port device team_slave_0 removed --- 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