usb: raw-gadget: fix memory leak in gadget_setup

Commit Message

Zhang, Qiang Oct. 27, 2020, 7:30 a.m. UTC

From: Zqiang <[e-mail]>

When fetch 'event' from event queue, after copy its address
space content to user space, the 'event' the memory space
pointed to by the 'event' pointer need be freed.

BUG: memory leak
unreferenced object 0xffff888110622660 (size 32):
  comm "softirq", pid 0, jiffies 4294941981 (age 12.480s)
  hex dump (first 32 bytes):
    02 00 00 00 08 00 00 00 80 06 00 01 00 00 40 00  ..............@.
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000efd29abd>] kmalloc include/linux/slab.h:554 [inline]
    [<00000000efd29abd>] raw_event_queue_add drivers/usb/gadget/legacy/raw_gadget.c:66 [inline]
    [<00000000efd29abd>] raw_queue_event drivers/usb/gadget/legacy/raw_gadget.c:225 [inline]
    [<00000000efd29abd>] gadget_setup+0xf6/0x220 drivers/usb/gadget/legacy/raw_gadget.c:343
    [<00000000952c4a46>] dummy_timer+0xb9f/0x14c0 drivers/usb/gadget/udc/dummy_hcd.c:1899
    [<0000000074ac2c54>] call_timer_fn+0x38/0x200 kernel/time/timer.c:1415
    [<00000000560a3a79>] expire_timers kernel/time/timer.c:1460 [inline]
    [<00000000560a3a79>] __run_timers.part.0+0x319/0x400 kernel/time/timer.c:1757
    [<000000009d9503d0>] __run_timers kernel/time/timer.c:1738 [inline]
    [<000000009d9503d0>] run_timer_softirq+0x3d/0x80 kernel/time/timer.c:1770
    [<000000009df27c89>] __do_softirq+0xcc/0x2c2 kernel/softirq.c:298
    [<000000007a3f1a47>] asm_call_irq_on_stack+0xf/0x20
    [<000000004a62cc2e>] __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
    [<000000004a62cc2e>] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
    [<000000004a62cc2e>] do_softirq_own_stack+0x32/0x40 arch/x86/kernel/irq_64.c:77
    [<00000000b0086800>] invoke_softirq kernel/softirq.c:393 [inline]
    [<00000000b0086800>] __irq_exit_rcu kernel/softirq.c:423 [inline]
    [<00000000b0086800>] irq_exit_rcu+0x91/0xc0 kernel/softirq.c:435
    [<00000000175f9523>] sysvec_apic_timer_interrupt+0x36/0x80 arch/x86/kernel/apic/apic.c:1091
    [<00000000a348e847>] asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631
    [<0000000060661100>] native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline]
    [<0000000060661100>] arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline]
    [<0000000060661100>] acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline]
    [<0000000060661100>] acpi_idle_do_entry+0xc3/0xd0 drivers/acpi/processor_idle.c:517
    [<000000003f413b99>] acpi_idle_enter+0x128/0x1f0 drivers/acpi/processor_idle.c:648
    [<00000000f5e5afb8>] cpuidle_enter_state+0xc9/0x650 drivers/cpuidle/cpuidle.c:237
    [<00000000d50d51fc>] cpuidle_enter+0x29/0x40 drivers/cpuidle/cpuidle.c:351
    [<00000000d674baed>] call_cpuidle kernel/sched/idle.c:132 [inline]
    [<00000000d674baed>] cpuidle_idle_call kernel/sched/idle.c:213 [inline]
    [<00000000d674baed>] do_idle+0x1c8/0x250 kernel/sched/idle.c:273

Reported-by: [e-mail]
Signed-off-by: Zqiang <[e-mail]>
---
 drivers/usb/gadget/legacy/raw_gadget.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Patch

diff --git a/drivers/usb/gadget/legacy/raw_gadget.c b/drivers/usb/gadget/legacy/raw_gadget.c
index e01e366d89cd..062dfac30399 100644
--- a/drivers/usb/gadget/legacy/raw_gadget.c
+++ b/drivers/usb/gadget/legacy/raw_gadget.c
@@ -564,9 +564,12 @@  static int raw_ioctl_event_fetch(struct raw_dev *dev, unsigned long value)
 		return -ENODEV;
 	}
 	length = min(arg.length, event->length);
-	if (copy_to_user((void __user *)value, event, sizeof(*event) + length))
+	if (copy_to_user((void __user *)value, event, sizeof(*event) + length)) {
+		kfree(event);
 		return -EFAULT;
+	}
 
+	kfree(event);
 	return 0;
 }