Re: memory leak in gadget_bind

[Andrey Konovalov]

On Fri, Oct 23, 2020 at 5:26 PM syzbot
<syzbot+0a4ec40b66726854dd11@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    f9893351 Merge tag 'kconfig-v5.10' of git://git.kernel.org..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=13ff53f7900000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=b8e9005328853c49
> dashboard link: https://syzkaller.appspot.com/bug?extid=0a4ec40b66726854dd11
> compiler:       gcc (GCC) 10.1.0-syz 20200507
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=177a731c500000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1328d038500000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+0a4ec40b66726854dd11@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> BUG: memory leak
> unreferenced object 0xffff888110c4d9c0 (size 32):
>   comm "syz-executor693", pid 8462, jiffies 4294942114 (age 13.040s)
>   hex dump (first 32 bytes):
>     01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>   backtrace:
>     [<00000000b2b2ae2f>] kmalloc include/linux/slab.h:554 [inline]
>     [<00000000b2b2ae2f>] raw_event_queue_add drivers/usb/gadget/legacy/raw_gadget.c:66 [inline]
>     [<00000000b2b2ae2f>] raw_queue_event drivers/usb/gadget/legacy/raw_gadget.c:225 [inline]
>     [<00000000b2b2ae2f>] gadget_bind+0x223/0x340 drivers/usb/gadget/legacy/raw_gadget.c:303
>     [<000000005cc0921f>] udc_bind_to_driver+0x62/0x150 drivers/usb/gadget/udc/core.c:1413
>     [<000000009fe15fa6>] usb_gadget_probe_driver+0x1c7/0x230 drivers/usb/gadget/udc/core.c:1476
>     [<00000000a41bab17>] raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:512 [inline]
>     [<00000000a41bab17>] raw_ioctl+0x5da/0xf30 drivers/usb/gadget/legacy/raw_gadget.c:1210
>     [<0000000085e98ccd>] vfs_ioctl fs/ioctl.c:48 [inline]
>     [<0000000085e98ccd>] __do_sys_ioctl fs/ioctl.c:753 [inline]
>     [<0000000085e98ccd>] __se_sys_ioctl fs/ioctl.c:739 [inline]
>     [<0000000085e98ccd>] __x64_sys_ioctl+0xfc/0x140 fs/ioctl.c:739
>     [<00000000b1e8d60c>] do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
>     [<0000000084cf691c>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> BUG: memory leak
> unreferenced object 0xffff88810ba5e4e0 (size 32):
>   comm "softirq", pid 0, jiffies 4294942152 (age 12.660s)
>   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:
>     [<00000000203e8439>] kmalloc include/linux/slab.h:554 [inline]
>     [<00000000203e8439>] raw_event_queue_add drivers/usb/gadget/legacy/raw_gadget.c:66 [inline]
>     [<00000000203e8439>] raw_queue_event drivers/usb/gadget/legacy/raw_gadget.c:225 [inline]
>     [<00000000203e8439>] gadget_setup+0xf6/0x220 drivers/usb/gadget/legacy/raw_gadget.c:343
>     [<000000009fb695b0>] dummy_timer+0xb9f/0x14c0 drivers/usb/gadget/udc/dummy_hcd.c:1899
>     [<00000000c61b4b01>] call_timer_fn+0x38/0x200 kernel/time/timer.c:1415
>     [<0000000044ef2390>] expire_timers kernel/time/timer.c:1460 [inline]
>     [<0000000044ef2390>] __run_timers.part.0+0x319/0x400 kernel/time/timer.c:1757
>     [<000000005e8b3107>] __run_timers kernel/time/timer.c:1738 [inline]
>     [<000000005e8b3107>] run_timer_softirq+0x3d/0x80 kernel/time/timer.c:1770
>     [<000000000af0f05c>] __do_softirq+0xcc/0x2c2 kernel/softirq.c:298
>     [<0000000065b29993>] asm_call_irq_on_stack+0xf/0x20
>     [<00000000670a912a>] __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
>     [<00000000670a912a>] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
>     [<00000000670a912a>] do_softirq_own_stack+0x32/0x40 arch/x86/kernel/irq_64.c:77
>     [<00000000b238919a>] invoke_softirq kernel/softirq.c:393 [inline]
>     [<00000000b238919a>] __irq_exit_rcu kernel/softirq.c:423 [inline]
>     [<00000000b238919a>] irq_exit_rcu+0x91/0xc0 kernel/softirq.c:435
>     [<00000000ab949bfc>] sysvec_apic_timer_interrupt+0x36/0x80 arch/x86/kernel/apic/apic.c:1091
>     [<00000000ae73d7f6>] asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631
>     [<00000000c54c318f>] native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline]
>     [<00000000c54c318f>] arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline]
>     [<00000000c54c318f>] acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline]
>     [<00000000c54c318f>] acpi_idle_do_entry+0xc3/0xd0 drivers/acpi/processor_idle.c:517
>     [<00000000ac55bfeb>] acpi_idle_enter+0x128/0x1f0 drivers/acpi/processor_idle.c:648
>     [<000000008d561dc0>] cpuidle_enter_state+0xc9/0x650 drivers/cpuidle/cpuidle.c:237
>     [<000000007b67805b>] cpuidle_enter+0x29/0x40 drivers/cpuidle/cpuidle.c:351
>     [<000000001370c1be>] call_cpuidle kernel/sched/idle.c:132 [inline]
>     [<000000001370c1be>] cpuidle_idle_call kernel/sched/idle.c:213 [inline]
>     [<000000001370c1be>] do_idle+0x1c8/0x250 kernel/sched/idle.c:273
>
> BUG: memory leak
> unreferenced object 0xffff888110f48b20 (size 32):
>   comm "softirq", pid 0, jiffies 4294942183 (age 12.350s)
>   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:
>     [<00000000203e8439>] kmalloc include/linux/slab.h:554 [inline]
>     [<00000000203e8439>] raw_event_queue_add drivers/usb/gadget/legacy/raw_gadget.c:66 [inline]
>     [<00000000203e8439>] raw_queue_event drivers/usb/gadget/legacy/raw_gadget.c:225 [inline]
>     [<00000000203e8439>] gadget_setup+0xf6/0x220 drivers/usb/gadget/legacy/raw_gadget.c:343
>     [<000000009fb695b0>] dummy_timer+0xb9f/0x14c0 drivers/usb/gadget/udc/dummy_hcd.c:1899
>     [<00000000c61b4b01>] call_timer_fn+0x38/0x200 kernel/time/timer.c:1415
>     [<0000000044ef2390>] expire_timers kernel/time/timer.c:1460 [inline]
>     [<0000000044ef2390>] __run_timers.part.0+0x319/0x400 kernel/time/timer.c:1757
>     [<000000005e8b3107>] __run_timers kernel/time/timer.c:1738 [inline]
>     [<000000005e8b3107>] run_timer_softirq+0x3d/0x80 kernel/time/timer.c:1770
>     [<000000000af0f05c>] __do_softirq+0xcc/0x2c2 kernel/softirq.c:298
>     [<0000000065b29993>] asm_call_irq_on_stack+0xf/0x20
>     [<00000000670a912a>] __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
>     [<00000000670a912a>] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
>     [<00000000670a912a>] do_softirq_own_stack+0x32/0x40 arch/x86/kernel/irq_64.c:77
>     [<00000000b238919a>] invoke_softirq kernel/softirq.c:393 [inline]
>     [<00000000b238919a>] __irq_exit_rcu kernel/softirq.c:423 [inline]
>     [<00000000b238919a>] irq_exit_rcu+0x91/0xc0 kernel/softirq.c:435
>     [<00000000ab949bfc>] sysvec_apic_timer_interrupt+0x36/0x80 arch/x86/kernel/apic/apic.c:1091
>     [<00000000ae73d7f6>] asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631
>     [<00000000c54c318f>] native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline]
>     [<00000000c54c318f>] arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline]
>     [<00000000c54c318f>] acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline]
>     [<00000000c54c318f>] acpi_idle_do_entry+0xc3/0xd0 drivers/acpi/processor_idle.c:517
>     [<00000000ac55bfeb>] acpi_idle_enter+0x128/0x1f0 drivers/acpi/processor_idle.c:648
>     [<000000008d561dc0>] cpuidle_enter_state+0xc9/0x650 drivers/cpuidle/cpuidle.c:237
>     [<000000007b67805b>] cpuidle_enter+0x29/0x40 drivers/cpuidle/cpuidle.c:351
>     [<000000001370c1be>] call_cpuidle kernel/sched/idle.c:132 [inline]
>     [<000000001370c1be>] cpuidle_idle_call kernel/sched/idle.c:213 [inline]
>     [<000000001370c1be>] do_idle+0x1c8/0x250 kernel/sched/idle.c:273

#syz fix: usb: raw-gadget: fix memory leak in gadget_setup