diff options
| author | Oliver Neukum <oneukum@suse.com> | 2024-09-12 15:21:22 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-09-13 07:54:54 +0200 |
| commit | 93907620b308609c72ba4b95b09a6aa2658bb553 (patch) | |
| tree | 6bf61b75c6b6b70ca88d8c6744d8c39fd604e495 /drivers/usb | |
| parent | 49cd2f4d747eeb3050b76245a7f72aa99dbd3310 (diff) | |
USB: misc: yurex: fix race between read and write
The write code path touches the bbu member in a non atomic manner
without taking the spinlock. Fix it.
The bug is as old as the driver.
Signed-off-by: Oliver Neukum <oneukum@suse.com>
CC: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240912132126.1034743-1-oneukum@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/misc/yurex.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/usb/misc/yurex.c b/drivers/usb/misc/yurex.c index 4745a320eae4..4a9859e03f6b 100644 --- a/drivers/usb/misc/yurex.c +++ b/drivers/usb/misc/yurex.c @@ -404,7 +404,6 @@ static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count, struct usb_yurex *dev; int len = 0; char in_buffer[MAX_S64_STRLEN]; - unsigned long flags; dev = file->private_data; @@ -419,9 +418,9 @@ static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count, return -EIO; } - spin_lock_irqsave(&dev->lock, flags); + spin_lock_irq(&dev->lock); scnprintf(in_buffer, MAX_S64_STRLEN, "%lld\n", dev->bbu); - spin_unlock_irqrestore(&dev->lock, flags); + spin_unlock_irq(&dev->lock); mutex_unlock(&dev->io_mutex); return simple_read_from_buffer(buffer, count, ppos, in_buffer, len); @@ -511,8 +510,11 @@ static ssize_t yurex_write(struct file *file, const char __user *user_buffer, __func__, retval); goto error; } - if (set && timeout) + if (set && timeout) { + spin_lock_irq(&dev->lock); dev->bbu = c2; + spin_unlock_irq(&dev->lock); + } return timeout ? count : -EIO; error: |