[syzbot] INFO: task hung in do_proc_bulk

[syzbot] INFO: task hung in do_proc_bulk

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    d5ae8d7f85b7 Revert "media: dvb header files: move some he..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=155fa21e300000
kernel config:  https://syzkaller.appspot.com/x/.config?x=2fd902af77ff1e56
dashboard link: https://syzkaller.appspot.com/bug?extid=ada0f7d3d9fd2016d927
compiler:       Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.1
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11a1ab0e300000

Bisection is inconclusive: the issue happens on the oldest tested release.

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=15662ee1300000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=17662ee1300000
console output: https://syzkaller.appspot.com/x/log.txt?x=13662ee1300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+ada0f7d3d9fd2016d927@syzkaller.appspotmail.com

INFO: task syz-executor.0:8700 blocked for more than 143 seconds.
      Not tainted 5.14.0-rc7-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:23192 pid: 8700 ppid:  8455 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4681 [inline]
 __schedule+0xc07/0x11f0 kernel/sched/core.c:5938
 schedule+0x14b/0x210 kernel/sched/core.c:6017
 schedule_timeout+0x98/0x2f0 kernel/time/timer.c:1857
 do_wait_for_common+0x2da/0x480 kernel/sched/completion.c:85
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion_timeout+0x46/0x60 kernel/sched/completion.c:157
 usb_start_wait_urb+0x167/0x550 drivers/usb/core/message.c:63
 do_proc_bulk+0x978/0x1080 drivers/usb/core/devio.c:1236
 proc_bulk drivers/usb/core/devio.c:1273 [inline]
 usbdev_do_ioctl drivers/usb/core/devio.c:2547 [inline]
 usbdev_ioctl+0x3441/0x6b10 drivers/usb/core/devio.c:2713
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:1069 [inline]
 __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:1055
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665e9
RSP: 002b:00007f15a90dc188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665e9
RDX: 0000000020000340 RSI: 00000000c0185502 RDI: 0000000000000004
RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffcc552e1bf R14: 00007f15a90dc300 R15: 0000000000022000

Showing all locks held in the system:
1 lock held by khungtaskd/1610:
 #0: ffffffff8c717ec0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 arch/x86/pci/mmconfig_64.c:151
1 lock held by in:imklog/8130:
 #0: ffff888035998870 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x24e/0x2f0 fs/file.c:974

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 1610 Comm: khungtaskd Not tainted 5.14.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1d3/0x29f lib/dump_stack.c:105
 nmi_cpu_backtrace+0x16c/0x190 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x191/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xd06/0xd50 kernel/hung_task.c:295
 kthread+0x453/0x480 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 10 Comm: kworker/u4:1 Not tainted 5.14.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
RIP: 0010:lock_is_held_type+0x1/0x180 kernel/locking/lockdep.c:5653
Code: 74 df 83 3d d8 22 e1 03 00 75 d6 48 c7 c7 80 c3 2e 8a 48 c7 c6 c0 c3 2e 8a 31 c0 e8 c9 8d 72 f7 0f 0b eb bd e8 90 fd ff ff 55 <41> 57 41 56 41 55 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00
RSP: 0018:ffffc90000cf7990 EFLAGS: 00000202
RAX: 1ffffffff18e3801 RBX: 1ffff9200019ef34 RCX: 0000000080000001
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff8c717e20
RBP: ffffc90000cf7a28 R08: dffffc0000000000 R09: fffffbfff1b74ee6
R10: fffffbfff1b74ee6 R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff9200019ef58 R14: dffffc0000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0a1e997000 CR3: 000000000c48e000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 lock_is_held include/linux/lockdep.h:283 [inline]
 rcu_read_lock_sched_held+0x87/0x110 kernel/rcu/update.c:125
 trace_lock_acquire+0x59/0x190 include/trace/events/lock.h:13
 lock_acquire+0xa4/0x4a0 kernel/locking/lockdep.c:5596
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:267
 rcu_read_lock include/linux/rcupdate.h:687 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:404 [inline]
 batadv_nc_worker+0xc8/0x5b0 net/batman-adv/network-coding.c:715
 process_one_work+0x833/0x10c0 kernel/workqueue.c:2276
 worker_thread+0xac1/0x1320 kernel/workqueue.c:2422
 kthread+0x453/0x480 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
----------------
Code disassembly (best guess):
   0:	74 df                	je     0xffffffe1
   2:	83 3d d8 22 e1 03 00 	cmpl   $0x0,0x3e122d8(%rip)        # 0x3e122e1
   9:	75 d6                	jne    0xffffffe1
   b:	48 c7 c7 80 c3 2e 8a 	mov    $0xffffffff8a2ec380,%rdi
  12:	48 c7 c6 c0 c3 2e 8a 	mov    $0xffffffff8a2ec3c0,%rsi
  19:	31 c0                	xor    %eax,%eax
  1b:	e8 c9 8d 72 f7       	callq  0xf7728de9
  20:	0f 0b                	ud2
  22:	eb bd                	jmp    0xffffffe1
  24:	e8 90 fd ff ff       	callq  0xfffffdb9
  29:	55                   	push   %rbp
* 2a:	41 57                	push   %r15 <-- trapping instruction
  2c:	41 56                	push   %r14
  2e:	41 55                	push   %r13
  30:	41 54                	push   %r12
  32:	53                   	push   %rbx
  33:	48 83 ec 10          	sub    $0x10,%rsp
  37:	65 48 8b 04 25 28 00 	mov    %gs:0x28,%rax
  3e:	00 00


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
syzbot can test patches for this issue, for details see:
https://goo.gl/tpsmEJ#testing-patches

Re: [syzbot] INFO: task hung in do_proc_bulk

[Alan Stern]

On Sat, Aug 28, 2021 at 08:52:17AM -0700, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    d5ae8d7f85b7 Revert "media: dvb header files: move some he..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=155fa21e300000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=2fd902af77ff1e56
> dashboard link: https://syzkaller.appspot.com/bug?extid=ada0f7d3d9fd2016d927
> compiler:       Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.1
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11a1ab0e300000
> 
> Bisection is inconclusive: the issue happens on the oldest tested release.
> 
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=15662ee1300000
> final oops:     https://syzkaller.appspot.com/x/report.txt?x=17662ee1300000
> console output: https://syzkaller.appspot.com/x/log.txt?x=13662ee1300000
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+ada0f7d3d9fd2016d927@syzkaller.appspotmail.com
> 
> INFO: task syz-executor.0:8700 blocked for more than 143 seconds.
>       Not tainted 5.14.0-rc7-syzkaller #0
> "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> task:syz-executor.0  state:D stack:23192 pid: 8700 ppid:  8455 flags:0x00004004
> Call Trace:
>  context_switch kernel/sched/core.c:4681 [inline]
>  __schedule+0xc07/0x11f0 kernel/sched/core.c:5938
>  schedule+0x14b/0x210 kernel/sched/core.c:6017
>  schedule_timeout+0x98/0x2f0 kernel/time/timer.c:1857
>  do_wait_for_common+0x2da/0x480 kernel/sched/completion.c:85
>  __wait_for_common kernel/sched/completion.c:106 [inline]
>  wait_for_common kernel/sched/completion.c:117 [inline]
>  wait_for_completion_timeout+0x46/0x60 kernel/sched/completion.c:157
>  usb_start_wait_urb+0x167/0x550 drivers/usb/core/message.c:63
>  do_proc_bulk+0x978/0x1080 drivers/usb/core/devio.c:1236

Looks like the wait needs to be interruptible.

Alan Stern

#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git d5ae8d7f85b7

Index: usb-devel/drivers/usb/core/message.c
===================================================================
--- usb-devel.orig/drivers/usb/core/message.c
+++ usb-devel/drivers/usb/core/message.c
@@ -60,12 +60,18 @@ static int usb_start_wait_urb(struct urb
 		goto out;
 
 	expire = timeout ? msecs_to_jiffies(timeout) : MAX_SCHEDULE_TIMEOUT;
-	if (!wait_for_completion_timeout(&ctx.done, expire)) {
+	retval = wait_for_completion_interruptible_timeout(&ctx.done, expire);
+	if (retval <= 0) {
 		usb_kill_urb(urb);
-		retval = (ctx.status == -ENOENT ? -ETIMEDOUT : ctx.status);
+		if (retval < 0)
+			retval = -EINTR;
+		else if (ctx.status == -ENOENT)
+			retval = -ETIMEDOUT;
+		else
+			retval = ctx.status;
 
 		dev_dbg(&urb->dev->dev,
-			"%s timed out on ep%d%s len=%u/%u\n",
+			"%s timed out or interrupted on ep%d%s len=%u/%u\n",
 			current->comm,
 			usb_endpoint_num(&urb->ep->desc),
 			usb_urb_dir_in(urb) ? "in" : "out",

Re: [syzbot] INFO: task hung in do_proc_bulk

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+ada0f7d3d9fd2016d927@syzkaller.appspotmail.com

Tested on:

commit:         d5ae8d7f Revert "media: dvb header files: move some he..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel config:  https://syzkaller.appspot.com/x/.config?x=2fd902af77ff1e56
dashboard link: https://syzkaller.appspot.com/bug?extid=ada0f7d3d9fd2016d927
compiler:       Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.1
patch:          https://syzkaller.appspot.com/x/patch.diff?x=16c2799d300000

Note: testing is done by a robot and is best-effort only.

Re: [syzbot] INFO: task hung in do_proc_bulk

[Alan Stern]

Let's see if making the wait killable rather than interruptible fixes the 
issue.  This patch avoids modifying the regular usb_start_wait_urb(), 
creating a separate usbfs_start_wait_urb() just for this purpose.

Alan Stern

#syz test: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git d5ae8d7f85b7

Index: usb-devel/drivers/usb/core/devio.c
===================================================================
--- usb-devel.orig/drivers/usb/core/devio.c
+++ usb-devel/drivers/usb/core/devio.c
@@ -32,6 +32,7 @@
 #include <linux/usb.h>
 #include <linux/usbdevice_fs.h>
 #include <linux/usb/hcd.h>	/* for usbcore internals */
+#include <linux/usb/quirks.h>
 #include <linux/cdev.h>
 #include <linux/notifier.h>
 #include <linux/security.h>
@@ -1102,14 +1103,55 @@ static int usbdev_release(struct inode *
 	return 0;
 }
 
+static void usbfs_blocking_completion(struct urb *urb)
+{
+	complete((struct completion *) urb->context);
+}
+
+/*
+ * Much like usb_start_wait_urb, but returns status separately from
+ * actual_length and uses a killable wait.
+ */
+static int usbfs_start_wait_urb(struct urb *urb, int timeout,
+		unsigned int *actlen)
+{
+	DECLARE_COMPLETION_ONSTACK(ctx);
+	unsigned long expire;
+	int rc;
+
+	urb->context = &ctx;
+	urb->complete = usbfs_blocking_completion;
+	*actlen = 0;
+	rc = usb_submit_urb(urb, GFP_KERNEL);
+	if (unlikely(rc))
+		return rc;
+
+	expire = (timeout ? msecs_to_jiffies(timeout) : MAX_SCHEDULE_TIMEOUT);
+	rc = wait_for_completion_killable_timeout(&ctx, expire);
+	if (rc <= 0) {
+		usb_kill_urb(urb);
+		*actlen = urb->actual_length;
+		if (urb->status != -ENOENT)
+			;	/* Completed before it was killed */
+		else if (rc < 0)
+			return -EINTR;
+		else
+			return -ETIMEDOUT;
+	}
+	*actlen = urb->actual_length;
+	return urb->status;
+}
+
 static int do_proc_control(struct usb_dev_state *ps,
 		struct usbdevfs_ctrltransfer *ctrl)
 {
 	struct usb_device *dev = ps->dev;
 	unsigned int tmo;
 	unsigned char *tbuf;
-	unsigned wLength;
+	unsigned wLength, actlen;
 	int i, pipe, ret;
+	struct urb *urb = NULL;
+	struct usb_ctrlrequest *dr = NULL;
 
 	ret = check_ctrlrecip(ps, ctrl->bRequestType, ctrl->bRequest,
 			      ctrl->wIndex);
@@ -1122,51 +1164,63 @@ static int do_proc_control(struct usb_de
 			sizeof(struct usb_ctrlrequest));
 	if (ret)
 		return ret;
+
+	ret = -ENOMEM;
 	tbuf = (unsigned char *)__get_free_page(GFP_KERNEL);
-	if (!tbuf) {
-		ret = -ENOMEM;
+	if (!tbuf)
 		goto done;
-	}
+	urb = usb_alloc_urb(0, GFP_NOIO);
+	if (!urb)
+		goto done;
+	dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_NOIO);
+	if (!dr)
+		goto done;
+
+	dr->bRequestType = ctrl->bRequestType;
+	dr->bRequest = ctrl->bRequest;
+	dr->wValue = cpu_to_le16(ctrl->wValue);
+	dr->wIndex = cpu_to_le16(ctrl->wIndex);
+	dr->wLength = cpu_to_le16(ctrl->wLength);
+
 	tmo = ctrl->timeout;
 	snoop(&dev->dev, "control urb: bRequestType=%02x "
 		"bRequest=%02x wValue=%04x "
 		"wIndex=%04x wLength=%04x\n",
 		ctrl->bRequestType, ctrl->bRequest, ctrl->wValue,
 		ctrl->wIndex, ctrl->wLength);
-	if ((ctrl->bRequestType & USB_DIR_IN) && ctrl->wLength) {
+
+	if ((ctrl->bRequestType & USB_DIR_IN) && wLength) {
 		pipe = usb_rcvctrlpipe(dev, 0);
-		snoop_urb(dev, NULL, pipe, ctrl->wLength, tmo, SUBMIT, NULL, 0);
+		usb_fill_control_urb(urb, dev, pipe, (unsigned char *) dr, tbuf,
+				wLength, NULL, NULL);
+		snoop_urb(dev, NULL, pipe, wLength, tmo, SUBMIT, NULL, 0);
 
 		usb_unlock_device(dev);
-		i = usb_control_msg(dev, pipe, ctrl->bRequest,
-				    ctrl->bRequestType, ctrl->wValue, ctrl->wIndex,
-				    tbuf, ctrl->wLength, tmo);
+		i = usbfs_start_wait_urb(urb, tmo, &actlen);
 		usb_lock_device(dev);
-		snoop_urb(dev, NULL, pipe, max(i, 0), min(i, 0), COMPLETE,
-			  tbuf, max(i, 0));
-		if ((i > 0) && ctrl->wLength) {
-			if (copy_to_user(ctrl->data, tbuf, i)) {
+		snoop_urb(dev, NULL, pipe, actlen, i, COMPLETE, tbuf, actlen);
+		if (!i && actlen) {
+			if (copy_to_user(ctrl->data, tbuf, actlen)) {
 				ret = -EFAULT;
-				goto done;
+				goto recv_fault;
 			}
 		}
 	} else {
-		if (ctrl->wLength) {
-			if (copy_from_user(tbuf, ctrl->data, ctrl->wLength)) {
+		if (wLength) {
+			if (copy_from_user(tbuf, ctrl->data, wLength)) {
 				ret = -EFAULT;
 				goto done;
 			}
 		}
 		pipe = usb_sndctrlpipe(dev, 0);
-		snoop_urb(dev, NULL, pipe, ctrl->wLength, tmo, SUBMIT,
-			tbuf, ctrl->wLength);
+		usb_fill_control_urb(urb, dev, pipe, (unsigned char *) dr, tbuf,
+				wLength, NULL, NULL);
+		snoop_urb(dev, NULL, pipe, wLength, tmo, SUBMIT, tbuf, wLength);
 
 		usb_unlock_device(dev);
-		i = usb_control_msg(dev, pipe, ctrl->bRequest,
-				    ctrl->bRequestType, ctrl->wValue, ctrl->wIndex,
-				    tbuf, ctrl->wLength, tmo);
+		i = usbfs_start_wait_urb(urb, tmo, &actlen);
 		usb_lock_device(dev);
-		snoop_urb(dev, NULL, pipe, max(i, 0), min(i, 0), COMPLETE, NULL, 0);
+		snoop_urb(dev, NULL, pipe, actlen, i, COMPLETE, NULL, 0);
 	}
 	if (i < 0 && i != -EPIPE) {
 		dev_printk(KERN_DEBUG, &dev->dev, "usbfs: USBDEVFS_CONTROL "
@@ -1174,8 +1228,15 @@ static int do_proc_control(struct usb_de
 			   current->comm, ctrl->bRequestType, ctrl->bRequest,
 			   ctrl->wLength, i);
 	}
-	ret = i;
+	ret = (i < 0 ? i : actlen);
+
+ recv_fault:
+	/* Linger a bit, prior to the next control message. */
+	if (dev->quirks & USB_QUIRK_DELAY_CTRL_MSG)
+		msleep(200);
  done:
+	kfree(dr);
+	usb_free_urb(urb);
 	free_page((unsigned long) tbuf);
 	usbfs_decrease_memory_usage(PAGE_SIZE + sizeof(struct urb) +
 			sizeof(struct usb_ctrlrequest));
@@ -1195,10 +1256,11 @@ static int do_proc_bulk(struct usb_dev_s
 		struct usbdevfs_bulktransfer *bulk)
 {
 	struct usb_device *dev = ps->dev;
-	unsigned int tmo, len1, pipe;
-	int len2;
+	unsigned int tmo, len1, len2, pipe;
 	unsigned char *tbuf;
 	int i, ret;
+	struct urb *urb = NULL;
+	struct usb_host_endpoint *ep;
 
 	ret = findintfep(ps->dev, bulk->ep);
 	if (ret < 0)
@@ -1206,14 +1268,17 @@ static int do_proc_bulk(struct usb_dev_s
 	ret = checkintf(ps, ret);
 	if (ret)
 		return ret;
+
+	len1 = bulk->len;
+	if (len1 < 0 || len1 >= (INT_MAX - sizeof(struct urb)))
+		return -EINVAL;
+
 	if (bulk->ep & USB_DIR_IN)
 		pipe = usb_rcvbulkpipe(dev, bulk->ep & 0x7f);
 	else
 		pipe = usb_sndbulkpipe(dev, bulk->ep & 0x7f);
-	if (!usb_maxpacket(dev, pipe, !(bulk->ep & USB_DIR_IN)))
-		return -EINVAL;
-	len1 = bulk->len;
-	if (len1 >= (INT_MAX - sizeof(struct urb)))
+	ep = usb_pipe_endpoint(dev, pipe);
+	if (!ep || !usb_endpoint_maxp(&ep->desc))
 		return -EINVAL;
 	ret = usbfs_increase_memory_usage(len1 + sizeof(struct urb));
 	if (ret)
@@ -1223,17 +1288,29 @@ static int do_proc_bulk(struct usb_dev_s
 	 * len1 can be almost arbitrarily large.  Don't WARN if it's
 	 * too big, just fail the request.
 	 */
+	ret = -ENOMEM;
 	tbuf = kmalloc(len1, GFP_KERNEL | __GFP_NOWARN);
-	if (!tbuf) {
-		ret = -ENOMEM;
+	if (!tbuf)
 		goto done;
+	urb = usb_alloc_urb(0, GFP_KERNEL);
+	if (!urb)
+		goto done;
+
+	if ((ep->desc.bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) ==
+			USB_ENDPOINT_XFER_INT) {
+		pipe = (pipe & ~(3 << 30)) | (PIPE_INTERRUPT << 30);
+		usb_fill_int_urb(urb, dev, pipe, tbuf, len1,
+				NULL, NULL, ep->desc.bInterval);
+	} else {
+		usb_fill_bulk_urb(urb, dev, pipe, tbuf, len1, NULL, NULL);
 	}
+
 	tmo = bulk->timeout;
 	if (bulk->ep & 0x80) {
 		snoop_urb(dev, NULL, pipe, len1, tmo, SUBMIT, NULL, 0);
 
 		usb_unlock_device(dev);
-		i = usb_bulk_msg(dev, pipe, tbuf, len1, &len2, tmo);
+		i = usbfs_start_wait_urb(urb, tmo, &len2);
 		usb_lock_device(dev);
 		snoop_urb(dev, NULL, pipe, len2, i, COMPLETE, tbuf, len2);
 
@@ -1253,12 +1330,13 @@ static int do_proc_bulk(struct usb_dev_s
 		snoop_urb(dev, NULL, pipe, len1, tmo, SUBMIT, tbuf, len1);
 
 		usb_unlock_device(dev);
-		i = usb_bulk_msg(dev, pipe, tbuf, len1, &len2, tmo);
+		i = usbfs_start_wait_urb(urb, tmo, &len2);
 		usb_lock_device(dev);
 		snoop_urb(dev, NULL, pipe, len2, i, COMPLETE, NULL, 0);
 	}
 	ret = (i < 0 ? i : len2);
  done:
+	usb_free_urb(urb);
 	kfree(tbuf);
 	usbfs_decrease_memory_usage(len1 + sizeof(struct urb));
 	return ret;

Re: [syzbot] INFO: task hung in do_proc_bulk

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+ada0f7d3d9fd2016d927@syzkaller.appspotmail.com

Tested on:

commit:         d5ae8d7f Revert "media: dvb header files: move some he..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel config:  https://syzkaller.appspot.com/x/.config?x=2fd902af77ff1e56
dashboard link: https://syzkaller.appspot.com/bug?extid=ada0f7d3d9fd2016d927
compiler:       Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.1
patch:          https://syzkaller.appspot.com/x/patch.diff?x=112280a3300000

Note: testing is done by a robot and is best-effort only.