From: Zqiang <qiang.zhang@xxxxxxxxxxxxx> 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: syzbot+bd38200f53df6259e6bf@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Zqiang <qiang.zhang@xxxxxxxxxxxxx> --- drivers/usb/gadget/legacy/raw_gadget.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) 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; } -- 2.17.1