On Wed, Jun 02, 2021 at 04:30:18PM -0700, syzbot wrote:

Hello,

syzbot found the following issue on:

HEAD commit:    7652dd2c USB: core: Check buffer length matches wLength fo..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
console output: https://syzkaller.appspot.com/x/log.txt?x=1712b99dd00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=1206ee92dd3d988d
dashboard link: https://syzkaller.appspot.com/bug?extid=7dbcd9ff34dc4ed45240
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16b82e13d00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16ac418dd00000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7dbcd9ff34dc4ed45240@syzkaller.appspotmail.com

usb 1-1: config 0 interface 186 altsetting 4 has a duplicate endpoint with address 0x8, skipping
usb 1-1: config 0 interface 166 has no altsetting 0
usb 1-1: config 0 interface 186 has no altsetting 0
------------[ cut here ]------------
usb 1-1: BOGUS control dir, pipe 80000280 doesn't match bRequestType 80
WARNING: CPU: 1 PID: 2632 at drivers/usb/core/urb.c:410 usb_submit_urb+0x149d/0x18a0 drivers/usb/core/urb.c:410
Modules linked in:
CPU: 1 PID: 2632 Comm: kworker/1:2 Not tainted 5.13.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usb_hub_wq hub_event
RIP: 0010:usb_submit_urb+0x149d/0x18a0 drivers/usb/core/urb.c:410
Code: 7c 24 40 e8 c5 1f b3 fd 48 8b 7c 24 40 e8 6b a6 1b ff 45 89 e8 44 89 f1 4c 89 e2 48 89 c6 48 c7 c7 80 0a 63 86 e8 15 ec fb 01 <0f> 0b e9 a5 ee ff ff e8 97 1f b3 fd 0f b6 1d db a7 34 05 31 ff 41
RSP: 0018:ffffc90000207680 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff8881182df058 RCX: 0000000000000000
RDX: ffff888114871b40 RSI: ffffffff812a6033 RDI: fffff52000040ec2
RBP: ffff88810cfffc80 R08: 0000000000000001 R09: 0000000000000000
R10: ffffffff814b998b R11: 0000000000000000 R12: ffff88810cfff6b8
R13: 0000000000000080 R14: 0000000080000280 R15: ffff88810e736f00
FS:  0000000000000000(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f13a00114f0 CR3: 0000000108807000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 usb_start_wait_urb+0x101/0x4c0 drivers/usb/core/message.c:58
 usb_internal_control_msg drivers/usb/core/message.c:102 [inline]
 usb_control_msg+0x31c/0x4a0 drivers/usb/core/message.c:153
 usb_get_string+0xa6/0x190 drivers/usb/core/message.c:837
 usb_string_sub+0x35e/0x3d0 drivers/usb/core/message.c:883
 usb_get_langid drivers/usb/core/message.c:913 [inline]
 usb_string+0x1cc/0x540 drivers/usb/core/message.c:977
 usb_cache_string+0x82/0x120 drivers/usb/core/message.c:1023
 usb_enumerate_device drivers/usb/core/hub.c:2399 [inline]
 usb_new_device+0x15b/0x7d0 drivers/usb/core/hub.c:2527
 hub_port_connect drivers/usb/core/hub.c:5298 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5438 [inline]
 port_event drivers/usb/core/hub.c:5584 [inline]
 hub_event+0x2357/0x4330 drivers/usb/core/hub.c:5666
 process_one_work+0x98d/0x1580 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x38c/0x460 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git 7652dd2c

Index: usb-devel/drivers/usb/core/message.c
===================================================================

--- usb-devel.orig/drivers/usb/core/message.c
+++ usb-devel/drivers/usb/core/message.c

@@ -832,6 +832,8 @@ static int usb_get_string(struct usb_dev
 	int i;
 	int result;
 
+	if (size <= 0)		/* No point in asking for no data */
+		return -EINVAL;
 	for (i = 0; i < 3; ++i) {
 		/* retry on length 0 or stall; some devices are flakey */
 		result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),