From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f71.google.com (mail-oo1-f71.google.com [209.85.161.71]) (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 AAA3F34C98C for ; Tue, 7 Apr 2026 23:52:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.71 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775605941; cv=none; b=HMAW64ciruVSyFzUJbsxBBZYMjbdhxJfAtkWkC0HE1DYgjheoM84/FzME9PzGy2gSop29KomBHBQpDc3I5HdwidjHaU2MoxYfcD68SC76l1/vUToOBeqm7XKZ8pZ98Jiv+BUMdGhLWqF+pUGVL4okkjCttd6qda1BeRMnd21w6w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775605941; c=relaxed/simple; bh=GuHyk6m3JGtUG5fCmLjRsmujBK1lP0nl7RTo/BkiI/w=; h=MIME-Version:Date:Message-ID:Subject:From:To:Cc:Content-Type; b=ZiDKZYdpRGdMwjkc9G2WILA5MJrbMBcmlwCC7RSLpTfGUBBNc3Lc4wMcbq01+0KH84tdj7AnJ7gZcFISUkHPBUiVXKKf1wbNNTSTfWZCinYgy4UzJdgZIJu17LAWKirkzcnylvUDNU3gmcqyUfLD4zdnbxT0yK0BbPY5cU6XsZA= 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=209.85.161.71 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-oo1-f71.google.com with SMTP id 006d021491bc7-6853c243911so6216079eaf.0 for ; Tue, 07 Apr 2026 16:52:19 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1775605938; x=1776210738; h=cc:to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=k2cyPX6vd8Wl13v/8L80T9BGY68jKOEGujfzaNqSIrA=; b=eOxnHaQSIdxVjOijuEp6Evou8/Dj85NHbfVky7HOGQ3iH2FvD4zfoHaiOLzul43rZv XjgIP4uY51wMs8QJnf4FpzP2OIc1jz7X+ENB/N+R1Eb4LNPUvFPFIZEpLB6EXA79baPE kWxSZXzJLD6cSIPYhHkonrYhpRPi6Gf9uwEY809/IOEtcP9rkWrNFz3ukEAFtb4eng2G Er6zMbdERlziSzbI9iaNBcDyVubI0Fjqqc/wVNi3/X56ZneU6sowhhrKiGqMEcEwjOVc dBiXYPYX4LT7s6ZzKas+V1X1jUXM7N0RShwTltq6PcZvjC20QDy4w4tDwH0aquH4t9Lb O49w== X-Gm-Message-State: AOJu0YwVDEAoDlmN0XD8b6CbLZ3CL/YajhWMkOkHNlv9mUM7NHJRgqAN 2NK3YUoDRD1y31HdsjLZ9mALgi0RD/oFHnhcMCLrL8MkYENbCDIslz+HVBVmNy/EbNgMOe/E/54 SE3aEF1TcmtAYYBZABMyFx8lKJAdzXNkT280gu0qUivQhP3he1EEz0LeQ2F8= Precedence: bulk X-Mailing-List: syzbot@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:200d:b0:687:57eb:baac with SMTP id 006d021491bc7-68757ec161emr4382690eaf.31.1775605938610; Tue, 07 Apr 2026 16:52:18 -0700 (PDT) Date: Tue, 07 Apr 2026 16:52:18 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69d598b2.050a0220.28fc4.0004.GAE@google.com> Subject: [moderation/CI] Re: net_sched: fix skb memory leak in deferred qdisc drops From: syzbot ci To: syzkaller-upstream-moderation@googlegroups.com Cc: syzbot@lists.linux.dev 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. The email will later be sent 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] If the report looks fine to you, reply with: #syz upstream If the report is a false positive, reply with #syz invalid