diff options
| author | Vu Nguyen Anh Khoa <khoavna.tin.2225@gmail.com> | 2026-06-21 15:57:43 +0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2026-07-17 15:49:30 +0200 |
| commit | 937cd823bb2c950a935dbd32313586911caae2f2 (patch) | |
| tree | f816b04865b1a809a32cceb413d4ba27b9523580 | |
| parent | 6994c8b4ef95114073a51d6143185bca39d6e5d5 (diff) | |
misc: nsm: do not unlock mutex before locking it
nsm_dev_ioctl() jumps to the common out label when the initial
copy_from_user() fails. That failure path runs before
mutex_lock(&nsm->lock), but the out label unconditionally calls
mutex_unlock(&nsm->lock).
Return -EFAULT directly for the pre-lock copy_from_user() failure so
only paths that acquired the mutex release it.
Signed-off-by: Vu Nguyen Anh Khoa <khoavna.tin.2225@gmail.com>
Reviewed-by: Alexander Graf <graf@amazon.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patch.msgid.link/20260621085743.76329-2-khoavna.tin.2225@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/misc/nsm.c | 3 |
1 files changed, 1 insertions, 2 deletions
diff --git a/drivers/misc/nsm.c b/drivers/misc/nsm.c index ef7b32742340..e39ff00714f7 100644 --- a/drivers/misc/nsm.c +++ b/drivers/misc/nsm.c @@ -365,9 +365,8 @@ static long nsm_dev_ioctl(struct file *file, unsigned int cmd, return -EINVAL; /* Copy user argument struct to kernel argument struct */ - r = -EFAULT; if (copy_from_user(&raw, argp, _IOC_SIZE(cmd))) - goto out; + return -EFAULT; mutex_lock(&nsm->lock); |