From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from www2881.sakura.ne.jp (www2881.sakura.ne.jp [49.212.198.91]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0C32724DFF3; Wed, 25 Mar 2026 09:12:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=49.212.198.91 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774429952; cv=none; b=FRjerPndDfgUvfPjolpSNBwTNdio2fvtDb3CzNlXr2g0XJ/igqTPtvQVlrhXqg2w8Bfj7OkKLtB66aTW6yCPj/H9STkJ/QE3IuTCf4zo6SdAwe0g6tFmWYpQZe+0MKt3w0YWNTMg/ZTu6YMf8duQipFiwE5aD3CeMfAILVG9rh8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774429952; c=relaxed/simple; bh=7sjIAF6Y4pA90r8SW6hjDbE4KQgDXlaYo44sYcV1hYs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JQkLFsKcZ899Pi/IGl2XbBGsg34C0WYJy1N6gOmj857TxHAHAJgA8wl7TTAk9R7hHj8Vw+qC8Dcp/xJ24bNNuE5DteSC1nbzet9pcphzUFvTVKKt1StCYZIff6NqIZBhLcOwVjKPd2ccaFIQxm6CpFWR0hHgTTSKFbiK3GLw5xk= ARC-Authentication-Results:i=1; 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t=1774429935; v=1; b=xOo+/+6SkW+y2AbaNR8+H/hPfyZfkBGEzmUVxJOrhsNwSwQSjrtwCpIO6M0QdiNE e6wEfhaM0SgbsUFC9613PXvet01H8SngXCaH4LdacswYnQ/pkRnI8NIB8o5zZOnB VzW8h+8oMMc7YYzqJqwA8wwBpoglNxKqFjxE8o6fClKjnejAVHLrdrV53GL4nY/s /2HhFxPJ25SsPkVzt3PX/4//13AXm8UKfW/NgLoBm5eqzd6bBWRYilRLyWMiUAT9 tD1XN6ca/uREXgiD/MlW/TwgA0rscoziopMoJHy3liLd7OZgoHsnwN1Z+i0hFrCr d9RbS738WorbeHClr02Ryw== From: Kohei Enju To: syzbot+9db6c624635564ad813c@syzkaller.appspotmail.com Cc: kuniyu@google.com, andrew+netdev@lunn.ch, linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org, netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [usb?] [net?] KMSAN: uninit-value in rtl8150_open (2) Date: Wed, 25 Mar 2026 18:12:09 +0900 Message-ID: <20260325091214.24516-1-kohei@enjuk.jp> X-Mailer: git-send-email 2.53.0 In-Reply-To: <69c34b1c.050a0220.abc16.000b.GAE@google.com> References: <69c34b1c.050a0220.abc16.000b.GAE@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit + Iwashima-san On Tue, 24 Mar 2026 19:40:28 -0700, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: c612261bedd6 Merge tag 'io_uring-7.0-20260320' of git://gi.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=155801d6580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=963de479f54c6dbb > dashboard link: https://syzkaller.appspot.com/bug?extid=9db6c624635564ad813c > compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 > > Unfortunately, I don't have any reproducer for this issue yet. > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/aa2bdf537bf6/disk-c612261b.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/8fcd98072431/vmlinux-c612261b.xz > kernel image: https://storage.googleapis.com/syzbot-assets/737b94c52155/bzImage-c612261b.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+9db6c624635564ad813c@syzkaller.appspotmail.com > > usb 2-1: device reset failed > ===================================================== > BUG: KMSAN: uninit-value in set_carrier drivers/net/usb/rtl8150.c:726 [inline] > BUG: KMSAN: uninit-value in rtl8150_open+0x1131/0x1360 drivers/net/usb/rtl8150.c:763 > set_carrier drivers/net/usb/rtl8150.c:726 [inline] > rtl8150_open+0x1131/0x1360 drivers/net/usb/rtl8150.c:763 > __dev_open+0x8e3/0xd40 net/core/dev.c:1702 > __dev_change_flags+0x32f/0x950 net/core/dev.c:9764 > netif_change_flags+0x8d/0x1e0 net/core/dev.c:9827 > dev_change_flags+0x18c/0x320 net/core/dev_api.c:68 > devinet_ioctl+0x10dd/0x25a0 net/ipv4/devinet.c:1199 > inet_ioctl+0x4c0/0x6f0 net/ipv4/af_inet.c:1015 > sock_do_ioctl net/socket.c:1254 [inline] > sock_ioctl+0x769/0x1140 net/socket.c:1375 > vfs_ioctl fs/ioctl.c:51 [inline] > __do_sys_ioctl fs/ioctl.c:597 [inline] > __se_sys_ioctl+0x23c/0x400 fs/ioctl.c:583 > __x64_sys_ioctl+0x97/0xe0 fs/ioctl.c:583 > x64_sys_call+0x1975/0x3ea0 arch/x86/include/generated/asm/syscalls_64.h:17 > do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] > do_syscall_64+0x134/0xf80 arch/x86/entry/syscall_64.c:94 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > Local variable tmp.i created at: > set_carrier drivers/net/usb/rtl8150.c:723 [inline] > rtl8150_open+0xc26/0x1360 drivers/net/usb/rtl8150.c:763 > __dev_open+0x8e3/0xd40 net/core/dev.c:1702 I see Iwashima-san was previously working on this issue here: https://lore.kernel.org/all/20250827233108.3768855-1-kuniyu@google.com/T/ The issue seems to be that set_carrier() ignores the return value of get_registers() and may use an uninitialized tmp. rtl8150 appears to have other call sites that use get_registers() the same way as mentioned in the thread above.