From: Kohei Enju <kohei@enjuk.jp>
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 [thread overview]
Message-ID: <20260325091214.24516-1-kohei@enjuk.jp> (raw)
In-Reply-To: <69c34b1c.050a0220.abc16.000b.GAE@google.com>
+ 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.
next prev parent reply other threads:[~2026-03-25 9:12 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-25 2:40 [syzbot] [usb?] [net?] KMSAN: uninit-value in rtl8150_open (2) syzbot
2026-03-25 9:12 ` Kohei Enju [this message]
2026-03-26 0:33 ` Kuniyuki Iwashima
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