From: Johan Hovold <johan@kernel.org> stable inclusion from stable-v6.12.97 commit 3c0a7b29ebb391d5f50b115e86f842b709195b08 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16637 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit c602254ba4c10f60a73cd99d147874f86a3f485c ] mutex_unlock() may access the mutex structure after releasing the lock and therefore cannot be used to manage lifetime of objects directly (unlike spinlocks and refcounts). [1][2] Use a kref to release the driver data to avoid use-after-free in mutex_unlock() when release() races with disconnect(). [1] a51749ab34d9 ("locking/mutex: Document that mutex_unlock() is non-atomic") [2] 2b9d9e0a9ba0 ("locking/mutex: Clarify that mutex_unlock(), and most other sleeping locks, can still use the lock object after it's unlocked") Fixes: 946b960d13c1 ("USB: add driver for iowarrior devices.") Cc: stable <stable@kernel.org> Reported-by: Yue Sun <samsun1006219@gmail.com> Link: https://lore.kernel.org/r/20260618080204.38322-1-samsun1006219@gmail.com Signed-off-by: Johan Hovold <johan@kernel.org> Link: https://patch.msgid.link/20260622152612.116422-2-johan@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Conflicts: drivers/usb/misc/iowarrior.c [ context conflicts. ] Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> --- drivers/usb/misc/iowarrior.c | 57 +++++++++++++++--------------------- 1 file changed, 24 insertions(+), 33 deletions(-) diff --git a/drivers/usb/misc/iowarrior.c b/drivers/usb/misc/iowarrior.c index 30606208ce60..0f959a3c1103 100644 --- a/drivers/usb/misc/iowarrior.c +++ b/drivers/usb/misc/iowarrior.c @@ -66,6 +66,7 @@ static DEFINE_MUTEX(iowarrior_open_disc_lock); /* Structure to hold all of our device specific stuff */ struct iowarrior { + struct kref kref; struct mutex mutex; /* locks this structure */ struct usb_device *udev; /* save off the usb device pointer */ struct usb_interface *interface; /* the interface for this device */ @@ -237,8 +238,10 @@ static void iowarrior_write_callback(struct urb *urb) /** * iowarrior_delete */ -static inline void iowarrior_delete(struct iowarrior *dev) +static inline void iowarrior_delete(struct kref *kref) { + struct iowarrior *dev = container_of(kref, struct iowarrior, kref); + kfree(dev->int_in_buffer); usb_free_urb(dev->int_in_urb); kfree(dev->read_queue); @@ -616,6 +619,9 @@ static int iowarrior_open(struct inode *inode, struct file *file) } /* increment our usage count for the driver */ ++dev->opened; + + kref_get(&dev->kref); + /* save our object in the file's private structure */ file->private_data = dev; retval = 0; @@ -632,7 +638,6 @@ static int iowarrior_open(struct inode *inode, struct file *file) static int iowarrior_release(struct inode *inode, struct file *file) { struct iowarrior *dev; - int retval = 0; dev = file->private_data; if (!dev) @@ -640,29 +645,18 @@ static int iowarrior_release(struct inode *inode, struct file *file) /* lock our device */ mutex_lock(&dev->mutex); + dev->opened = 0; /* we're closing now */ - if (dev->opened <= 0) { - retval = -ENODEV; /* close called more than once */ - mutex_unlock(&dev->mutex); - } else { - dev->opened = 0; /* we're closing now */ - retval = 0; - if (dev->present) { - /* - The device is still connected so we only shutdown - pending read-/write-ops. - */ - usb_kill_urb(dev->int_in_urb); - wake_up_interruptible(&dev->read_wait); - wake_up_interruptible(&dev->write_wait); - mutex_unlock(&dev->mutex); - } else { - /* The device was unplugged, cleanup resources */ - mutex_unlock(&dev->mutex); - iowarrior_delete(dev); - } + if (dev->present) { + usb_kill_urb(dev->int_in_urb); + wake_up_interruptible(&dev->read_wait); + wake_up_interruptible(&dev->write_wait); } - return retval; + mutex_unlock(&dev->mutex); + + kref_put(&dev->kref, iowarrior_delete); + + return 0; } static __poll_t iowarrior_poll(struct file *file, poll_table * wait) @@ -747,6 +741,7 @@ static int iowarrior_probe(struct usb_interface *interface, if (!dev) return retval; + kref_init(&dev->kref); mutex_init(&dev->mutex); atomic_set(&dev->intr_idx, 0); @@ -844,7 +839,8 @@ static int iowarrior_probe(struct usb_interface *interface, return retval; error: - iowarrior_delete(dev); + kref_put(&dev->kref, iowarrior_delete); + return retval; } @@ -875,19 +871,14 @@ static void iowarrior_disconnect(struct usb_interface *interface) usb_kill_anchored_urbs(&dev->submitted); if (dev->opened) { - /* There is a process that holds a filedescriptor to the device , - so we only shutdown read-/write-ops going on. - Deleting the device is postponed until close() was called. - */ usb_kill_urb(dev->int_in_urb); wake_up_interruptible(&dev->read_wait); wake_up_interruptible(&dev->write_wait); - mutex_unlock(&dev->mutex); - } else { - /* no process is using the device, cleanup now */ - mutex_unlock(&dev->mutex); - iowarrior_delete(dev); } + + mutex_unlock(&dev->mutex); + + kref_put(&dev->kref, iowarrior_delete); } /* usb specific object needed to register this driver with the usb subsystem */ -- 2.34.1