2023-12-19 06:37:18

by Harshit Mogalapalli

[permalink] [raw]
Subject: [PATCH] usb: yurex: Fix inconsistent locking bug in yurex_read()

Unlock before returning on the error path.

Fixes: 86b20af11e84 ("usb: yurex: Replace snprintf() with the safer scnprintf() variant")
Reported-by: Dan Carpenter <[email protected]>
Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/r/[email protected]/
Signed-off-by: Harshit Mogalapalli <[email protected]>
---
drivers/usb/misc/yurex.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/misc/yurex.c b/drivers/usb/misc/yurex.c
index 5a13cddace0e..9a0649d23693 100644
--- a/drivers/usb/misc/yurex.c
+++ b/drivers/usb/misc/yurex.c
@@ -414,8 +414,10 @@ static ssize_t yurex_read(struct file *file, char __user *buffer, size_t count,
return -ENODEV;
}

- if (WARN_ON_ONCE(dev->bbu > S64_MAX || dev->bbu < S64_MIN))
+ if (WARN_ON_ONCE(dev->bbu > S64_MAX || dev->bbu < S64_MIN)) {
+ mutex_unlock(&dev->io_mutex);
return -EIO;
+ }

spin_lock_irqsave(&dev->lock, flags);
scnprintf(in_buffer, MAX_S64_STRLEN, "%lld\n", dev->bbu);
--
2.42.0