Date:   Thu, 2 Feb 2023 15:49:53 -0500
From:   Alan Stern <stern@rowland.harvard.edu>
To:     syzbot <syzbot+2a0e7abd24f1eb90ce25@syzkaller.appspotmail.com>
Cc:     gregkh@linuxfoundation.org, kuba@kernel.org,
        linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org,
        mailhol.vincent@wanadoo.fr, mkl@pengutronix.de, oneukum@suse.com,
        syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] WARNING in __usbnet_read_cmd/usb_submit_urb
Message-ID: <Y9wh8dGK6oHSjJQl@rowland.harvard.edu>
References: <00000000000008f1d405f1999228@google.com>
 <00000000000052099f05f3b3e298@google.com>
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On Thu, Feb 02, 2023 at 01:06:45AM -0800, syzbot wrote:
> syzbot has found a reproducer for the following issue on:
> 
> HEAD commit:    9f266ccaa2f5 Merge tag 'for_linus' of git://git.kernel.org..
> git tree:       upstream
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=103b6ea5480000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=94f93727847d4d81
> dashboard link: https://syzkaller.appspot.com/bug?extid=2a0e7abd24f1eb90ce25
> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13c8afb3480000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14bebfb5480000
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/710b69f64bd2/disk-9f266cca.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/f155d6966517/vmlinux-9f266cca.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/07672b7ba2df/bzImage-9f266cca.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+2a0e7abd24f1eb90ce25@syzkaller.appspotmail.com
> 
> ------------[ cut here ]------------
> usb 1-1: BOGUS control dir, pipe 80000280 doesn't match bRequestType c0
> WARNING: CPU: 0 PID: 4645 at drivers/usb/core/urb.c:411 usb_submit_urb+0x14a7/0x1880 drivers/usb/core/urb.c:411
> Modules linked in:
> CPU: 1 PID: 4645 Comm: dhcpcd Not tainted 6.2.0-rc6-syzkaller-00050-g9f266ccaa2f5 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
> RIP: 0010:usb_submit_urb+0x14a7/0x1880 drivers/usb/core/urb.c:411
> Code: 7c 24 40 e8 ab 4c 80 fb 48 8b 7c 24 40 e8 71 14 01 ff 45 89 e8 44 89 f1 4c 89 e2 48 89 c6 48 c7 c7 20 b0 fa 8a e8 d3 ab be 03 <0f> 0b e9 9f ee ff ff e8 7d 4c 80 fb 0f b6 1d 17 b2 5c 08 31 ff 41
> RSP: 0018:ffffc9000355f5a0 EFLAGS: 00010282
> RAX: 0000000000000000 RBX: ffff888017d2c058 RCX: 0000000000000000
> RDX: ffff88801f901d40 RSI: ffffffff816680ec RDI: fffff520006abea6
> RBP: ffff88801cc501e0 R08: 0000000000000005 R09: 0000000000000000
> R10: 0000000080000000 R11: 0000000000000000 R12: ffff888017a92d98
> R13: 00000000000000c0 R14: 0000000080000280 R15: ffff888017a25200
> FS:  00007f2a38e6d740(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007f2f3dabf300 CR3: 0000000021a8d000 CR4: 00000000003506e0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  <TASK>
>  usb_start_wait_urb+0x101/0x4b0 drivers/usb/core/message.c:58
>  usb_internal_control_msg drivers/usb/core/message.c:102 [inline]
>  usb_control_msg+0x320/0x4a0 drivers/usb/core/message.c:153
>  __usbnet_read_cmd+0xb9/0x390 drivers/net/usb/usbnet.c:2010
>  usbnet_read_cmd+0x96/0xf0 drivers/net/usb/usbnet.c:2068
>  pl_vendor_req drivers/net/usb/plusb.c:60 [inline]
>  pl_set_QuickLink_features drivers/net/usb/plusb.c:75 [inline]
>  pl_reset+0x2f/0xf0 drivers/net/usb/plusb.c:85
>  usbnet_open+0xcc/0x5d0 drivers/net/usb/usbnet.c:889
>  __dev_open+0x297/0x4d0 net/core/dev.c:1417
>  __dev_change_flags+0x587/0x750 net/core/dev.c:8530
>  dev_change_flags+0x97/0x170 net/core/dev.c:8602
>  devinet_ioctl+0x15a2/0x1d70 net/ipv4/devinet.c:1147
>  inet_ioctl+0x33f/0x380 net/ipv4/af_inet.c:979
>  sock_do_ioctl+0xcc/0x230 net/socket.c:1169
>  sock_ioctl+0x1f8/0x680 net/socket.c:1286
>  vfs_ioctl fs/ioctl.c:51 [inline]
>  __do_sys_ioctl fs/ioctl.c:870 [inline]
>  __se_sys_ioctl fs/ioctl.c:856 [inline]
>  __x64_sys_ioctl+0x197/0x210 fs/ioctl.c:856
>  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>  do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
>  entry_SYSCALL_64_after_hwframe+0x63/0xcd
> RIP: 0033:0x7f2a38f5b0e7
> Code: 3c 1c e8 1c ff ff ff 85 c0 79 87 49 c7 c4 ff ff ff ff 5b 5d 4c 89 e0 41 5c c3 66 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 61 9d 0c 00 f7 d8 64 89 01 48
> RSP: 002b:00007ffd77152e38 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
> RAX: ffffffffffffffda RBX: 00007f2a38e6d6c8 RCX: 00007f2a38f5b0e7
> RDX: 00007ffd77163028 RSI: 0000000000008914 RDI: 0000000000000018
> RBP: 00007ffd771731d8 R08: 00007ffd77162fe8 R09: 00007ffd77162f98
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007ffd77163028 R14: 0000000000000028 R15: 0000000000008914
>  </TASK>

A zero-length USB transfer is a write, not a read.

Alan Stern

#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/  9f266ccaa2f5

Index: usb-devel/drivers/net/usb/plusb.c
===================================================================
--- usb-devel.orig/drivers/net/usb/plusb.c
+++ usb-devel/drivers/net/usb/plusb.c
@@ -57,9 +57,7 @@
 static inline int
 pl_vendor_req(struct usbnet *dev, u8 req, u8 val, u8 index)
 {
-	return usbnet_read_cmd(dev, req,
-				USB_DIR_IN | USB_TYPE_VENDOR |
-				USB_RECIP_DEVICE,
+	return usbnet_write_cmd(dev, req, USB_TYPE_VENDOR | USB_RECIP_DEVICE,
 				val, index, NULL, 0);
 }