From: Harshal Chaudhari <harshalchau04@gmail.com>
To: gregkh@linuxfoundation.org
Cc: arnd@arndb.de, sudipm.mukherjee@gmail.com,
linux-kernel@vger.kernel.org, harshalchau04@gmail.com
Subject: [PATCH] char: ppdev: check if ioctl argument is present and valid
Date: Thu, 8 Oct 2020 23:57:13 +0530 [thread overview]
Message-ID: <20201008182713.2764-1-harshalchau04@gmail.com> (raw)
Checking the argument passed to the ioctl is valid
or not. if not then return -EINVAL.
Signed-off-by: Harshal Chaudhari <harshalchau04@gmail.com>
---
drivers/char/ppdev.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/char/ppdev.c b/drivers/char/ppdev.c
index 38b46c7d1737..001392980202 100644
--- a/drivers/char/ppdev.c
+++ b/drivers/char/ppdev.c
@@ -354,7 +354,7 @@ static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
unsigned int minor = iminor(file_inode(file));
struct pp_struct *pp = file->private_data;
struct parport *port;
- void __user *argp = (void __user *)arg;
+ void __user *argp = NULL;
struct ieee1284_info *info;
unsigned char reg;
unsigned char mask;
@@ -364,6 +364,16 @@ static int pp_do_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
struct timespec64 ts;
int ret;
+ if (_IOC_TYPE(cmd) != PP_IOCTL)
+ return -ENOTTY;
+
+ /* check if ioctl argument is present and valid */
+ if (_IOC_DIR(cmd) != _IOC_NONE) {
+ argp = (void __user *)arg;
+ if (!argp)
+ return -EINVAL;
+ }
+
/* First handle the cases that don't take arguments. */
switch (cmd) {
case PPCLAIM:
--
2.17.1
next reply other threads:[~2020-10-08 18:27 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-08 18:27 Harshal Chaudhari [this message]
2020-10-08 19:35 ` [PATCH] char: ppdev: check if ioctl argument is present and valid Arnd Bergmann
2020-10-09 4:57 ` Greg KH
2020-10-10 0:08 ` Sudip Mukherjee
2020-10-10 9:10 ` Sudip Mukherjee
2020-10-13 9:01 ` harshal chaudhari
2020-10-13 10:58 ` Greg KH
2020-10-13 11:12 ` David Laight
[not found] ` <CAFEvwu=76mPtXSEgpwSoRC0rC0tkU5BiEx1X5O2VwVSPJ7m4Rw@mail.gmail.com>
2020-10-24 19:21 ` Arnd Bergmann
2020-10-24 20:16 ` harshal chaudhari
2020-10-24 21:22 ` David Laight
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