From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo2-f6.google.com (mail-oo2-f6.google.com [74.125.231.134]) (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 AF33E2EB10 for ; Wed, 2 Sep 2026 00:23:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.231.134 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788308614; cv=none; b=pA+mmwqYGuhVbkhFMNSyJT7gTJu7ETuRvSTnvq2zgtpCeQN4lZ1i7c06Yl9d4oTn6Ruo3LpeZyBJqOEMg88N1dXwAm2KE6TB08rU1YNbUUrAyN6qYQrAq2YLQNofzNXPZ92C5Rt3Vh45F8KA0WPKzaQOG21dcSSVvdtsLGUV+us= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788308614; c=relaxed/simple; bh=/y6NWVFREyIb7dyi4XE6+zQbOzqGko5Ub0NX5ovQpYY=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=cYpY1dX9XfPCUH48DYQjNnVa6bZbwgK+wwcfrxFaRqUOlYp5U2MP+AN4NU0j6y/B29GBZG45GM5BqguCn8uFECc9O2tfae9bUC6/AEJczPLfcexJNQMKKTFluUMqg/8Y5kbB/U5pwQAayKizFstZOx1oDLOv4SodARhk3K3z3Ag= 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=74.125.231.134 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-oo2-f6.google.com with SMTP id 006d021491bc7-6aafac56856so112214eaf.1 for ; Tue, 01 Sep 2026 17:23:32 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788308611; x=1788913411; h=content-type:to:from:subject:message-id:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=8JSmnxQApi8XjQdw22ipTDSC+e2v8+0n5C7epgLYDig=; b=m1nv49rJvZKGIS7J9LhGgXzV44D//WkI58dOQmP6bvFIEnpx6b1prvI1PpmPWuIhwb VwlplKAnsIUpDQfxQW1rt36f5Kne6o2R/SWg750hk5eipKkVDzCSuihXYfkFtigShQuV 93RTFMdLVoqKQ2Y52RtjNCjMhbY8JfIJouWftcNH1kVz7XwloiJs/D0GLAS9Ch65N8TZ eQ6kaDHQnhEnAHGtv4Yu61IeiZ8o3+gpTElP6OTzWoPmDCEOd9/JjCrt5UJX+o7U3Dbg Dae1jLAmGBXv8hFXHnzrgl+6FW9j9WJ3Y0WCTXXumBb+DYBQKjTO2iXka7QM9lEnC8DC ycCA== X-Forwarded-Encrypted: i=1; AHgh+RrZU7x681xGWze+8G0k5Uw+7Iey4NRKapCVO4r7sDGtl1niXkLTDHdhw0F3kfnQPfalB/w8+igtvb2S@vger.kernel.org X-Gm-Message-State: AFuF++kZWOZYoROSVMc48C35w8aqIjsvEI2+BC9XrfcDCye9UcGK35nn za/NonEDnxJcFXMSTtUexBGriKuloKAYQutVGYiFvgow6x4E0znEa5M0xmkn7tr9/gsALkJlXBI mEO4X1usnKxk97Hc9GWfqh2znUUW7w/10JInqX+5mn3rUdcVWal0os8JOKIs= Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:161e:b0:6ac:b178:97f9 with SMTP id 006d021491bc7-6b48193f585mr620743eaf.31.1788308611663; Tue, 01 Sep 2026 17:23:31 -0700 (PDT) Date: Tue, 01 Sep 2026 17:23:31 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a976c83.9266084e.bf0d7.0003.GAE@google.com> Subject: [syzbot] [rdma?] WARNING: refcount bug in iwpm_find_nlmsg_request From: syzbot To: jgg@ziepe.ca, leon@kernel.org, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 548e7bcd0c54 Merge tag 'ceph-for-7.3-rc1' of https://githu.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11644c15580000 kernel config: https://syzkaller.appspot.com/x/.config?x=85bc5cc2fc7394d9 dashboard link: https://syzkaller.appspot.com/bug?extid=bd317784d628820741b5 compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 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-548e7bcd.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/33981fd8947d/vmlinux-548e7bcd.xz kernel image: https://storage.googleapis.com/syzbot-assets/d17bd4bd3299/bzImage-548e7bcd.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+bd317784d628820741b5@syzkaller.appspotmail.com netlink: 16 bytes leftover after parsing attributes in process `syz.2.3511'. iwpm_mapping_error_cb: Received msg seq = 0 err code = 5 client = 2 ------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: lib/refcount.c:25 at refcount_warn_saturate+0x111/0x130 lib/refcount.c:25, CPU#0: syz.2.3511/18531 Modules linked in: CPU: 0 UID: 0 PID: 18531 Comm: syz.2.3511 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:refcount_warn_saturate+0x111/0x130 lib/refcount.c:25 Code: 06 e8 53 6d e3 fc 48 8d 3d dc 53 28 0c 67 48 0f b9 3a e8 42 6d e3 fc 5b 5d c3 cc cc cc cc e8 36 6d e3 fc 48 8d 3d cf 53 28 0c <67> 48 0f b9 3a e8 25 6d e3 fc 5b 5d e9 ce 8f a8 06 48 89 df e8 46 RSP: 0000:ffffc90007ddf448 EFLAGS: 00010087 RAX: 0000000000001c55 RBX: ffff888024890878 RCX: ffffc9000c001000 RDX: 0000000000080000 RSI: ffffffff8527c5fa RDI: ffffffff915019d0 RBP: 0000000000000002 R08: 0000000000000005 R09: 0000000000000004 R10: 0000000000000002 R11: 000000000000001f R12: ffff888024890878 R13: dffffc0000000000 R14: 0000000000000283 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888096968000(0063) knlGS:00000000f5456b40 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: 00000000f73d8568 CR3: 00000000774e3000 CR4: 0000000000352ef0 DR0: 0000000000000009 DR1: 0000000000000009 DR2: 0000000000000003 DR3: 0000000000000008 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: __refcount_add include/linux/refcount.h:289 [inline] __refcount_inc include/linux/refcount.h:366 [inline] refcount_inc include/linux/refcount.h:383 [inline] kref_get include/linux/kref.h:45 [inline] iwpm_find_nlmsg_request+0x13d/0x160 drivers/infiniband/core/iwpm_util.c:360 iwpm_mapping_error_cb.cold+0x97/0x277 drivers/infiniband/core/iwpm_msg.c:794 netlink_dump+0x532/0xd00 net/netlink/af_netlink.c:2331 __netlink_dump_start+0x6d6/0x990 net/netlink/af_netlink.c:2446 netlink_dump_start include/linux/netlink.h:341 [inline] rdma_nl_rcv_msg+0x568/0x6f0 drivers/infiniband/core/netlink.c:190 rdma_nl_rcv_skb.constprop.0.isra.0+0x2cb/0x410 drivers/infiniband/core/netlink.c:239 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x585/0x850 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1900 sock_sendmsg_nosec net/socket.c:800 [inline] __sock_sendmsg net/socket.c:815 [inline] ____sys_sendmsg+0xa4d/0xbe0 net/socket.c:2713 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2767 __sys_sendmsg+0x160/0x210 net/socket.c:2799 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x13a/0x8b0 arch/x86/entry/syscall_32.c:291 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:316 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7f94fec Code: Unable to access opcode bytes at 0xf7f94fc2. RSP: 002b:00000000f545650c EFLAGS: 00000292 ORIG_RAX: 0000000000000172 RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 0000000080000100 RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: e8 53 6d e3 fc call 0xfce36d58 5: 48 8d 3d dc 53 28 0c lea 0xc2853dc(%rip),%rdi # 0xc2853e8 c: 67 48 0f b9 3a ud1 (%edx),%rdi 11: e8 42 6d e3 fc call 0xfce36d58 16: 5b pop %rbx 17: 5d pop %rbp 18: c3 ret 19: cc int3 1a: cc int3 1b: cc int3 1c: cc int3 1d: e8 36 6d e3 fc call 0xfce36d58 22: 48 8d 3d cf 53 28 0c lea 0xc2853cf(%rip),%rdi # 0xc2853f8 * 29: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2e: e8 25 6d e3 fc call 0xfce36d58 33: 5b pop %rbx 34: 5d pop %rbp 35: e9 ce 8f a8 06 jmp 0x6a89008 3a: 48 89 df mov %rbx,%rdi 3d: e8 .byte 0xe8 3e: 46 rex.RX --- 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