From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f72.google.com (mail-ot1-f72.google.com [209.85.210.72]) (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 20D1A3537FB for ; Wed, 8 Apr 2026 06:45:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.72 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775630732; cv=none; b=TjgEcoXqa7OxaUEUNi69t+IJrBRWieKCb1eMEPmPcMl0FCQVlzhbhf3daMTBtzcqBi/aoYlGx613wxhrRFlkGSlcP7XEgN0XlfeDf11fqE1ay6AOhTVIBVk+1PR2jS6gVBjkh84FyDF4sKgSEHgm1XqTtOMOOpiXYqqjGWsaU4Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775630732; c=relaxed/simple; bh=xgEC+WfL2idF4NX3OWD/q4qLDceolgtCSjaHyw0T6To=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To:Cc: Content-Type; b=HWAdIi5v96NTW97YszbkP2YEDz5cRIFnMGwbIr8+PR0wp6jFwojbnK/wRFDePVj7PoOujOUDyypJK7CSlZGOzHFIG29/8VsZj2LRNsxf64lH8P4acUfnCGfl9ESF0OcejQhzFkRzVVQ3pHt3kbS7NO1IhvVxQEL9zIutg0ZqOO8= 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=209.85.210.72 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-ot1-f72.google.com with SMTP id 46e09a7af769-7dbb4f8b314so12786089a34.3 for ; Tue, 07 Apr 2026 23:45:29 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775630729; x=1776235529; h=cc:to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=7rEQTDJ7oEJhY7ymkpvRH1m82lHz0+1l7ZXL1EKQeIg=; b=YK9RuOOwYRSC8oDsjRCMGWuZQT0jKa5yTcutDPYNhhf9zehlRtRUlj8/bUum4oJjgF XowBbuHf6M+mQfPziHL0mf/v8TJd0RLnNwVmM+jSvq6dny6qC9s1gsbyWYWj/A69B2wL BDBZ9B0yMjqdJTVuMiTJ+d0EtbqG4SJpFFWmyndmpcY/DHh+oA881TjHkBNfEVhlIKfV /8nTZLmz8EEnz9jKUZYCcGOUUzyTYhcZC7vqWkgn8uw/PmczY7ma/SfmCzmvOtOf6Vjv 5uI530r/XF0g0iRHX3KTAOeMUro3KUbHm62GwZN3LlmO9lQfkhghawBk3opSXYpsbNP2 fYcg== X-Forwarded-Encrypted: i=1; AJvYcCV6AQDKj8PV36UcHB4GObm3LeVg4uEDh/AfoW3aVhI2rV477ROT3bN2qUIZYOcfDrDXwvrps5E=@vger.kernel.org X-Gm-Message-State: AOJu0YzrYj3ikYQyjFXEDhgduuV1Klv+NVCf5/nWQ1lpvP+2pP/HJkYz y0qTfdEzV7VAHOtyF7jDQ5ArL7xn5NkhssGZYjHTjX9m2+DOaDVB+Whkh5nt7vlYhtiSOaN3OYU faK4Qq7kkip5JjyP1YXvY32okqRtmQD9q0ExEdkcn1hju/8O5RyfflQzDmvU= Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:4b84:b0:67e:366b:53b7 with SMTP id 006d021491bc7-68220741a9dmr12203235eaf.53.1775630729067; Tue, 07 Apr 2026 23:45:29 -0700 (PDT) Date: Tue, 07 Apr 2026 23:45:29 -0700 In-Reply-To: <20260407170214.4157-2-fmancera@suse.de> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69d5f989.a00a0220.468cb.0009.GAE@google.com> Subject: [syzbot ci] Re: net_sched: fix skb memory leak in deferred qdisc drops From: syzbot ci To: damilola@aterlo.com, davem@davemloft.net, edumazet@google.com, fmancera@suse.de, horms@kernel.org, kuba@kernel.org, netdev@vger.kernel.org, pabeni@redhat.com Cc: syzbot@lists.linux.dev, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" syzbot ci has tested the following series [v1] net_sched: fix skb memory leak in deferred qdisc drops https://lore.kernel.org/all/20260407170214.4157-2-fmancera@suse.de * [PATCH net] net_sched: fix skb memory leak in deferred qdisc drops and found the following issue: WARNING: suspicious RCU usage in cake_dequeue Full report is available here: https://ci.syzbot.org/series/90acbb62-3e93-4bb7-af7a-51d555f5956b *** WARNING: suspicious RCU usage in cake_dequeue tree: net URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netdev/net.git base: a9b8b18364fffce4c451e6f6fd218fa4ab646705 arch: amd64 compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 config: https://ci.syzbot.org/builds/a5e0fad0-c9c8-4102-b2af-b4d1c7947ee3/config syz repro: https://ci.syzbot.org/findings/b1dd239a-f59f-414f-8bde-578258899e94/syz_repro ============================= WARNING: suspicious RCU usage syzkaller #0 Not tainted ----------------------------- ./include/net/sch_generic.h:581 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 2 locks held by syz.0.51/6016: #0: ffffffff8e75e640 (rcu_read_lock_bh){....}-{1:3}, at: local_bh_disable include/linux/bottom_half.h:20 [inline] #0: ffffffff8e75e640 (rcu_read_lock_bh){....}-{1:3}, at: rcu_read_lock_bh include/linux/rcupdate.h:903 [inline] #0: ffffffff8e75e640 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x277/0x3890 net/core/dev.c:4778 #1: ffff8881ad9e8170 (&sch->root_lock_key#31){+...}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline] #1: ffff8881ad9e8170 (&sch->root_lock_key#31){+...}-{3:3}, at: __dev_xmit_skb net/core/dev.c:4241 [inline] #1: ffff8881ad9e8170 (&sch->root_lock_key#31){+...}-{3:3}, at: __dev_queue_xmit+0xbf2/0x3890 net/core/dev.c:4819 stack backtrace: CPU: 1 UID: 0 PID: 6016 Comm: syz.0.51 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x13f/0x1d0 kernel/locking/lockdep.c:6876 qdisc_root_sleeping include/net/sch_generic.h:581 [inline] qdisc_dequeue_drop include/net/sch_generic.h:1173 [inline] cake_dequeue+0x23a7/0x4e50 net/sched/sch_cake.c:2240 dequeue_skb net/sched/sch_generic.c:297 [inline] qdisc_restart net/sched/sch_generic.c:402 [inline] __qdisc_run+0x26c/0x15d0 net/sched/sch_generic.c:420 qdisc_run include/net/pkt_sched.h:120 [inline] __dev_xmit_skb net/core/dev.c:4286 [inline] __dev_queue_xmit+0x1bad/0x3890 net/core/dev.c:4819 packet_snd net/packet/af_packet.c:3076 [inline] packet_sendmsg+0x3eb6/0x50f0 net/packet/af_packet.c:3108 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] __sys_sendto+0x672/0x710 net/socket.c:2206 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2209 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f077b39c819 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:00007f077c28c028 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f077b615fa0 RCX: 00007f077b39c819 RDX: 000000000000fc13 RSI: 0000200000000800 RDI: 0000000000000003 RBP: 00007f077b432c91 R08: 0000000000000000 R09: fffffffffffffef0 R10: 0000000000000880 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f077b616038 R14: 00007f077b615fa0 R15: 00007fffceb20038 *** If these findings have caused you to resend the series or submit a separate fix, please add the following tag to your commit message: Tested-by: syzbot@syzkaller.appspotmail.com --- This report is generated by a bot. It may contain errors. syzbot ci engineers can be reached at syzkaller@googlegroups.com. To test a patch for this bug, please reply with `#syz test` (should be on a separate line). The patch should be attached to the email. Note: arguments like custom git repos and branches are not supported.