From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f79.google.com (mail-ot1-f79.google.com [209.85.210.79]) (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 4914044DB9D for ; Thu, 8 Jan 2026 10:16:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.79 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767867384; cv=none; b=GraEo71cwo6qCVGEIa6U7Bck1Chh6O3D/Eft5F0YGYJRq5PzoJSCI7tNZ9lw2Vq8uYXCoiaUbpZJiyiRY2vZ6JzUWjp5+QG48aqflXAjyMDHC2oQVdG1h36TGJIC488pj2Obn09x1WKJ+sXArPliQzbvNWpXM0pDc/Ia57P+MfA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767867384; c=relaxed/simple; bh=r46TeTAsvXLyudt9PQ5TJmUtz6XZj6rTn/Rg5C2jtIw=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=cgWZdPOfpwAP1DlslTWSVPjhit5XLe0WZgkJVHvc2ZDno/gd0mWTj2uOq7wWF9PShqTcTfW1uxdPLuBBzFp7/T2c3faGV+WUo81DU/sCyI5vMtvzLERYKyWwEZ76vm1txTtVsg4T2sWBNzkF2RPTcCmHqI5a/N8XpbLgzNJ56Kk= 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=209.85.210.79 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-ot1-f79.google.com with SMTP id 46e09a7af769-7c7542602a7so6837742a34.2 for ; Thu, 08 Jan 2026 02:16:20 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1767867379; x=1768472179; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=HfzHvGppm2YPB7GFJv3lvZRdv00vKd6q9SmsqIhkZt4=; b=NbhGBeb6+LImYKT7L4QeENQ5cB5Ww8OZlNphMRpb7+df9JaFkX8aAHIeFGms52I4Em 9mMYFUHVTzRo/XYAf2GWbcHgmHsWYaERiiyxspJkmtDnXVbsHfIRtuwUuYcJz7OKUTmC nWgEVRAoHK/uPLK5wqbg0ea1yviIovTgZNNsh1kjm9XsFNw41VmRYG6MwtrWx5fr2nJh icankoL8S5tVXfF17kLxTmAVNAs2deA2cY6domXXdlVv76vqU2B6w9yGxzi06k1YkeK8 QAo9F4eCewgAgoMv7Ski972MuKChkgyvdFLCDn3nDzH6zY3RfmColgk00kgg4bFL9HrQ AG/w== X-Forwarded-Encrypted: i=1; AJvYcCWkaw88lKWcLLv9mOsSx9sEES/9KoZ6ado7boNpl13Vebtu4yojy/chj/KSGfHTplvRyWg92+F7/MXyJiQ=@vger.kernel.org X-Gm-Message-State: AOJu0Ywz7DfzT95lcugtBnKh2zDItJD0U61lTTSvLF46ubPC015lmMEt wf8X3JPMwIeEYbpWOUoL1P3ExJpqB837GLnIKMN1ebCXj1srKWnSasA8yRDBXsGsPvtR7AqHQeh JQtNrobqFWmF+paPQEoLrpkSKzjs4u++AjD2Qrw224uGJbK6t3mssBrSQu0o= X-Google-Smtp-Source: AGHT+IGlG9xMD/Xg43vd6VzYzy/bP8Xcm+nWbQlnZVG1oqAohaZtzbuXMPHk7W4Hw07khUgFjwxb+gmfZ2h9K/mOj5AnkwCpX6vv Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:a1a1:b0:65b:29af:b562 with SMTP id 006d021491bc7-65f5508542emr1552625eaf.77.1767867379436; Thu, 08 Jan 2026 02:16:19 -0800 (PST) Date: Thu, 08 Jan 2026 02:16:19 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <695f83f3.050a0220.1c677c.0392.GAE@google.com> Subject: [syzbot] [net?] KMSAN: kernel-infoleak in __skb_datagram_iter (5) From: syzbot To: davem@davemloft.net, 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: f0b9d8eb98df Merge tag 'nfsd-6.19-3' of git://git.kernel.o.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=13f9be9a580000 kernel config: https://syzkaller.appspot.com/x/.config?x=b3903bdf68407a14 dashboard link: https://syzkaller.appspot.com/bug?extid=bfc7323743ca6dbcc3d3 compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8 userspace arch: i386 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/d9ff9c5037b8/disk-f0b9d8eb.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/b3c97cb6b38c/vmlinux-f0b9d8eb.xz kernel image: https://storage.googleapis.com/syzbot-assets/d523f5e33ff5/bzImage-f0b9d8eb.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+bfc7323743ca6dbcc3d3@syzkaller.appspotmail.com ===================================================== BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline] BUG: KMSAN: kernel-infoleak in copy_to_user_iter lib/iov_iter.c:24 [inline] BUG: KMSAN: kernel-infoleak in iterate_ubuf include/linux/iov_iter.h:30 [inline] BUG: KMSAN: kernel-infoleak in iterate_and_advance2 include/linux/iov_iter.h:302 [inline] BUG: KMSAN: kernel-infoleak in iterate_and_advance include/linux/iov_iter.h:330 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_iter+0xef3/0x33f0 lib/iov_iter.c:197 instrument_copy_to_user include/linux/instrumented.h:114 [inline] copy_to_user_iter lib/iov_iter.c:24 [inline] iterate_ubuf include/linux/iov_iter.h:30 [inline] iterate_and_advance2 include/linux/iov_iter.h:302 [inline] iterate_and_advance include/linux/iov_iter.h:330 [inline] _copy_to_iter+0xef3/0x33f0 lib/iov_iter.c:197 copy_to_iter include/linux/uio.h:220 [inline] simple_copy_to_iter net/core/datagram.c:521 [inline] __skb_datagram_iter+0x196/0x12c0 net/core/datagram.c:402 skb_copy_datagram_iter+0x5b/0x1e0 net/core/datagram.c:535 skb_copy_datagram_msg include/linux/skbuff.h:4217 [inline] netlink_recvmsg+0x4bb/0xfe0 net/netlink/af_netlink.c:1951 sock_recvmsg_nosec net/socket.c:1078 [inline] sock_recvmsg+0x2df/0x390 net/socket.c:1100 ____sys_recvmsg+0x193/0x610 net/socket.c:2812 ___sys_recvmsg+0x20b/0x850 net/socket.c:2854 __sys_recvmsg net/socket.c:2887 [inline] __do_sys_recvmsg net/socket.c:2893 [inline] __se_sys_recvmsg net/socket.c:2890 [inline] __x64_sys_recvmsg+0x20e/0x3d0 net/socket.c:2890 x64_sys_call+0x38b7/0x3e70 arch/x86/include/generated/asm/syscalls_64.h:48 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xd3/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was stored to memory at: pskb_expand_head+0x310/0x15d0 net/core/skbuff.c:2290 netlink_trim+0x3a3/0x450 net/netlink/af_netlink.c:1299 netlink_broadcast_filtered+0x80/0x28f0 net/netlink/af_netlink.c:1512 nlmsg_multicast_filtered include/net/netlink.h:1165 [inline] nlmsg_multicast include/net/netlink.h:1184 [inline] nlmsg_notify+0x15b/0x2f0 net/netlink/af_netlink.c:2593 rtnl_notify+0xba/0x100 net/core/rtnetlink.c:958 wireless_nlevent_flush net/wireless/wext-core.c:354 [inline] wireless_nlevent_process+0xfe/0x290 net/wireless/wext-core.c:414 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xb91/0x1d80 kernel/workqueue.c:3340 worker_thread+0xedf/0x1590 kernel/workqueue.c:3421 kthread+0xd5c/0xf00 kernel/kthread.c:463 ret_from_fork+0x208/0x710 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Uninit was stored to memory at: wireless_send_event+0x652/0x1540 net/wireless/wext-core.c:580 ioctl_standard_iw_point+0x12b0/0x13f0 net/wireless/wext-core.c:896 compat_standard_call+0x188/0x4c0 net/wireless/wext-core.c:1108 wireless_process_ioctl net/wireless/wext-core.c:-1 [inline] wext_ioctl_dispatch+0x192/0x7a0 net/wireless/wext-core.c:1014 compat_wext_handle_ioctl+0x1a1/0x300 net/wireless/wext-core.c:1137 compat_sock_ioctl+0x20c/0xff0 net/socket.c:3530 __do_compat_sys_ioctl fs/ioctl.c:695 [inline] __se_compat_sys_ioctl fs/ioctl.c:638 [inline] __ia32_compat_sys_ioctl+0x7f9/0x1270 fs/ioctl.c:638 ia32_sys_call+0x25d9/0x4340 arch/x86/include/generated/asm/syscalls_32.h:55 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0x154/0x320 arch/x86/entry/syscall_32.c:307 do_fast_syscall_32+0x38/0x80 arch/x86/entry/syscall_32.c:332 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:370 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Local variable iwp created at: compat_standard_call+0x4a/0x4c0 net/wireless/wext-core.c:1095 wireless_process_ioctl net/wireless/wext-core.c:-1 [inline] wext_ioctl_dispatch+0x192/0x7a0 net/wireless/wext-core.c:1014 Bytes 60-63 of 64 are uninitialized Memory access of size 64 starts at ffff8881183ec000 Data copied to user address 00007ffe7d4a8260 CPU: 1 UID: 101 PID: 5458 Comm: dhcpcd Not tainted syzkaller #0 PREEMPT(none) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 ===================================================== --- 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