diff options
| author | Eli Billauer <eli.billauer@gmail.com> | 2022-11-17 10:18:25 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-11-23 21:44:04 +0300 |
| commit | c002f04c0bc79ec00d4beb75fb631d5bf37419bd (patch) | |
| tree | 3ca57977121e09f82a4124ee4ddabed96dd2e008 | |
| parent | 0ef77698b85603d21453daf32ae70f76ae62ccae (diff) | |
| download | linux-c002f04c0bc79ec00d4beb75fb631d5bf37419bd.tar.xz | |
char: xillybus: Fix trivial bug with mutex
@unit_mutex protects @unit from being freed, so obviously it should be
released after @unit is used, and not before.
This is a follow-up to commit 282a4b71816b ("char: xillybus: Prevent
use-after-free due to race condition") which ensures, among others, the
protection of @private_data after @unit_mutex has been released.
Reported-by: Hyunwoo Kim <imv4bel@gmail.com>
Signed-off-by: Eli Billauer <eli.billauer@gmail.com>
Link: https://lore.kernel.org/r/20221117071825.3942-1-eli.billauer@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/char/xillybus/xillybus_class.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/char/xillybus/xillybus_class.c b/drivers/char/xillybus/xillybus_class.c index 0f238648dcfe..e9a288e61c15 100644 --- a/drivers/char/xillybus/xillybus_class.c +++ b/drivers/char/xillybus/xillybus_class.c @@ -227,14 +227,15 @@ int xillybus_find_inode(struct inode *inode, break; } - mutex_unlock(&unit_mutex); - - if (!unit) + if (!unit) { + mutex_unlock(&unit_mutex); return -ENODEV; + } *private_data = unit->private_data; *index = minor - unit->lowest_minor; + mutex_unlock(&unit_mutex); return 0; } EXPORT_SYMBOL(xillybus_find_inode); |