From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-io1-f79.google.com (mail-io1-f79.google.com [209.85.166.79]) (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 F052130DD39 for ; Mon, 17 Nov 2025 07:50:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.79 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763365830; cv=none; b=NvP1lq+vDC288nWdKELUBC0RcNXAStLZZHCumtIIIhteguMRSqPqjdHYRdfTw55eDoT+6ro7eFnZRnEx0bNvFzD6LhQz3z7n3Uy4C9VLcI2dccnDObBRCxtuleA8GNevO7MnUVoiAn1ZhPkG59Jm18eYZ/HHhP2y548atSX2gNk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763365830; c=relaxed/simple; bh=exFxZ3Dp9XithKleRlTYAXSbYBc8o1depYcp8ANM0SM=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=GwjVByZQ1v1b2X1HZZxG4xvdDTTFg05HwNLgsjqkBeHePz5gJAk/Ax1zg6rhkkT2+2Mw3ZJRvKjIgiNZCuIjloQ++8Kumo5G4dKtUl8l18YasOMnqcwjA7I5BgvNdr0X1CrD+cN28gGe9kkHxZuCLmGIkgDPtBCSkGje/PTtf3U= 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=209.85.166.79 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-io1-f79.google.com with SMTP id ca18e2360f4ac-9486920a552so1080059639f.3 for ; Sun, 16 Nov 2025 23:50:28 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1763365828; x=1763970628; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=SR48UPog8jJajspAE3Vve4DfAYEMOezKWsvRTEEqnyI=; b=PZGx1SbgadG6VAEu8XEj+oBcM3vQ+mx9nOSSK67OE/B1ZXJubRht97DAqgsZ/IMZk/ 2oe7HZXwbdm5QlWZbYFBIqtm0ExqLb98SxygZd/6SIfcSY6iVXtifz2pVewmxKAZmUZn VBKqKEc4Y1343R1Fv90gXqjK8co+j/cZr82pVnMb2ulcOJFTPh52XS2lPpSC1zlQK4Mc pYQ+3fnMsCCmN8RgFHb6qaGMHMnwYU+7NdiUnp9Eow5qhWANwWKyMLG01OP9D+W4Tt5A vNNal1c5e9xWO5ypi8G9l7pi+A+bZiyJKvdAmI6VjUCtfzIJBNgPZTm4n2m6+/h8WGZg gh9A== X-Forwarded-Encrypted: i=1; AJvYcCX2PQ00iXYWRe7Oejh9L5LYtntJMJfeH7FdXF8fDwsKTDklyMBiECONg+TorVpzSsuL3T/ySe3Uz/l5uU8=@vger.kernel.org X-Gm-Message-State: AOJu0Yys3tFW0miVVKPU9agwzbI1LT9iuxVQcZ7YsE7spMJSgJB1KCaI qpKv/f9vQK5utoIbVjVhG7mhQHeK7EZGOgL1c/+Nq+knVg6A0bDoQunv3fzPkl4UcOVn9gGK/e7 6kb72HAxdj9YMDnjjmhcEBFNRYDMVR1jvdzUqpNc+gkoqhPQl2WQDkE0cUEQ= X-Google-Smtp-Source: AGHT+IGrxDGbCrzyXwSMXCo3r/6yUwB/4Wqa/qnuv7gyhBqhtBsxhDT3Tlb1v2YfKkjoZFzpt7c4eF7yI+GaJq7VZS7SLfQ0buyO 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:dd2:b0:434:96ea:ff6e with SMTP id e9e14a558f8ab-43496eb01cbmr74910925ab.39.1763365828007; Sun, 16 Nov 2025 23:50:28 -0800 (PST) Date: Sun, 16 Nov 2025 23:50:27 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <691ad3c3.a70a0220.f6df1.0005.GAE@google.com> Subject: [syzbot] [sctp?] WARNING: refcount bug in sctp_transport_put (5) From: syzbot To: davem@davemloft.net, edumazet@google.com, horms@kernel.org, kuba@kernel.org, linux-kernel@vger.kernel.org, linux-sctp@vger.kernel.org, lucien.xin@gmail.com, marcelo.leitner@gmail.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: 2ccec5944606 Merge tag 'erofs-for-6.18-rc6-fixes' of git:/.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=179c497c580000 kernel config: https://syzkaller.appspot.com/x/.config?x=19d831c6d0386a9c dashboard link: https://syzkaller.appspot.com/bug?extid=e94b93511bda261f4c43 compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 userspace arch: i386 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-2ccec594.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/a29a7f4d52f4/vmlinux-2ccec594.xz kernel image: https://storage.googleapis.com/syzbot-assets/1557802e0ae5/bzImage-2ccec594.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+e94b93511bda261f4c43@syzkaller.appspotmail.com ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 0 at lib/refcount.c:28 refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28 Modules linked in: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #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 RIP: 0010:refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28 Code: ff 89 de e8 88 82 1a fd 84 db 0f 85 66 ff ff ff e8 9b 87 1a fd c6 05 82 fe c8 0b 01 90 48 c7 c7 80 c3 ef 8b e8 b7 09 d9 fc 90 <0f> 0b 90 90 e9 43 ff ff ff e8 78 87 1a fd 0f b6 1d 5d fe c8 0b 31 RSP: 0018:ffffc90000007c30 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff817adc48 RDX: ffffffff8e097a00 RSI: ffffffff817adc55 RDI: 0000000000000001 RBP: ffff88806af5f820 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff88806af5f820 R13: 0000000000000101 R14: ffffffff8a96c630 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff88809780d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000003010cffc CR3: 000000005fddc000 CR4: 0000000000352ef0 Call Trace: __refcount_sub_and_test include/linux/refcount.h:400 [inline] __refcount_dec_and_test include/linux/refcount.h:432 [inline] refcount_dec_and_test include/linux/refcount.h:450 [inline] sctp_transport_put+0x12a/0x170 net/sctp/transport.c:476 call_timer_fn+0x19a/0x620 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers+0x6ef/0x960 kernel/time/timer.c:2372 __run_timer_base kernel/time/timer.c:2384 [inline] __run_timer_base kernel/time/timer.c:2376 [inline] run_timer_base+0x114/0x190 kernel/time/timer.c:2393 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2403 handle_softirqs+0x219/0x8e0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 97 6f 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d 83 b3 2c 00 fb f4 3c 0a 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e007df8 EFLAGS: 00000286 RAX: 0000000000c7ee29 RBX: 0000000000000000 RCX: ffffffff8b5d72a9 RDX: 0000000000000000 RSI: ffffffff8da28539 RDI: ffffffff8bf075c0 RBP: fffffbfff1c12f40 R08: 0000000000000001 R09: ffffed1005646655 R10: ffff88802b2332ab R11: 0000000000000001 R12: 0000000000000000 R13: ffffffff8e097a00 R14: ffffffff908244d0 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x38d/0x500 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 rest_init+0x16b/0x2b0 init/main.c:757 start_kernel+0x3f6/0x4e0 init/main.c:1111 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148 ---------------- Code disassembly (best guess): 0: 97 xchg %eax,%edi 1: 6f outsl %ds:(%rsi),(%dx) 2: 02 c3 add %bl,%al 4: cc int3 5: cc int3 6: cc int3 7: cc int3 8: 0f 1f 00 nopl (%rax) b: 90 nop c: 90 nop d: 90 nop e: 90 nop f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: f3 0f 1e fa endbr64 1f: eb 07 jmp 0x28 21: 0f 00 2d 83 b3 2c 00 verw 0x2cb383(%rip) # 0x2cb3ab 28: fb sti 29: f4 hlt * 2a: e9 3c 0a 03 00 jmp 0x30a6b <-- trapping instruction 2f: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 36: 00 00 00 39: 66 90 xchg %ax,%ax 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop --- 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