• Alan Stern's avatar
    USB: core: Prevent nested device-reset calls · 9c6d7788
    Alan Stern authored
    Automatic kernel fuzzing revealed a recursive locking violation in
    usb-storage:
    
    ============================================
    WARNING: possible recursive locking detected
    5.18.0 #3 Not tainted
    --------------------------------------------
    kworker/1:3/1205 is trying to acquire lock:
    ffff888018638db8 (&us_interface_key[i]){+.+.}-{3:3}, at:
    usb_stor_pre_reset+0x35/0x40 drivers/usb/storage/usb.c:230
    
    but task is already holding lock:
    ffff888018638db8 (&us_interface_key[i]){+.+.}-{3:3}, at:
    usb_stor_pre_reset+0x35/0x40 drivers/usb/storage/usb.c:230
    
    ...
    
    stack backtrace:
    CPU: 1 PID: 1205 Comm: kworker/1:3 Not tainted 5.18.0 #3
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
    1.13.0-1ubuntu1.1 04/01/2014
    Workqueue: usb_hub_wq hub_event
    Call Trace:
    <TASK>
    __dump_stack lib/dump_stack.c:88 [inline]
    dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
    print_deadlock_bug kernel/locking/lockdep.c:2988 [inline]
    check_deadlock kernel/locking/lockdep.c:3031 [inline]
    validate_chain kernel/locking/lockdep.c:3816 [inline]
    __lock_acquire.cold+0x152/0x3ca kernel/locking/lockdep.c:5053
    lock_acquire kernel/locking/lockdep.c:5665 [inline]
    lock_acquire+0x1ab/0x520 kernel/locking/lockdep.c:5630
    __mutex_lock_common kernel/locking/mutex.c:603 [inline]
    __mutex_lock+0x14f/0x1610 kernel/locking/mutex.c:747
    usb_stor_pre_reset+0x35/0x40 drivers/usb/storage/usb.c:230
    usb_reset_device+0x37d/0x9a0 drivers/usb/core/hub.c:6109
    r871xu_dev_remove+0x21a/0x270 drivers/staging/rtl8712/usb_intf.c:622
    usb_unbind_interface+0x1bd/0x890 drivers/usb/core/driver.c:458
    device_remove drivers/base/dd.c:545 [inline]
    device_remove+0x11f/0x170 drivers/base/dd.c:537
    __device_release_driver drivers/base/dd.c:1222 [inline]
    device_release_driver_internal+0x1a7/0x2f0 drivers/base/dd.c:1248
    usb_driver_release_interface+0x102/0x180 drivers/usb/core/driver.c:627
    usb_forced_unbind_intf+0x4d/0xa0 drivers/usb/core/driver.c:1118
    usb_reset_device+0x39b/0x9a0 drivers/usb/core/hub.c:6114
    
    This turned out not to be an error in usb-storage but rather a nested
    device reset attempt.  That is, as the rtl8712 driver was being
    unbound from a composite device in preparation for an unrelated USB
    reset (that driver does not have pre_reset or post_reset callbacks),
    its ->remove routine called usb_reset_device() -- thus nesting one
    reset call within another.
    
    Performing a reset as part of disconnect processing is a questionable
    practice at best.  However, the bug report points out that the USB
    core does not have any protection against nested resets.  Adding a
    reset_in_progress flag and testing it will prevent such errors in the
    future.
    
    Link: https://lore.kernel.org/all/CAB7eexKUpvX-JNiLzhXBDWgfg2T9e9_0Tw4HQ6keN==voRbP0g@mail.gmail.com/
    Cc: stable@vger.kernel.org
    Reported-and-tested-by: default avatarRondreis <linhaoguo86@gmail.com>
    Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
    Link: https://lore.kernel.org/r/YwkflDxvg0KWqyZK@rowland.harvard.eduSigned-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    9c6d7788
hub.c 179 KB