[PATCH] net: USB: Fix wrong-direction WARNING in plusb.c

[Alan Stern <stern@rowland.harvard.edu>]

The syzbot fuzzer detected a bug in the plusb network driver: A
zero-length control-OUT transfer was treated as a read instead of a
write.  In modern kernels this error provokes a WARNING:

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
...
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

The fix is to call usbnet_write_cmd() instead of usbnet_read_cmd() and
remove the USB_DIR_IN flag.

Reported-and-tested-by: syzbot+2a0e7abd24f1eb90ce25@syzkaller.appspotmail.com
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Fixes: 090ffa9d0e90 ("[PATCH] USB: usbnet (9/9) module for pl2301/2302 cables")
CC: stable@vger.kernel.org
Link: https://lore.kernel.org/r/00000000000052099f05f3b3e298@google.com/

---


[as1991]


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);
 }