From: Emil Goode <emilgoode@gmail.com>
To: gregkh@linuxfoundation.org
Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org,
Emil Goode <emilgoode@gmail.com>
Subject: [PATCH] drivers/tty: Use get_user instead of dereferencing user pointer
Date: Fri, 20 Apr 2012 17:52:34 +0200 [thread overview]
Message-ID: <1334937154-23037-1-git-send-email-emilgoode@gmail.com> (raw)
We should use the get_user macro instead of dereferencing user
pointers directly.
This patch fixes the following sparse warning:
drivers/tty/n_tty.c:1648:51: warning:
dereference of noderef expression
Signed-off-by: Emil Goode <emilgoode@gmail.com>
---
I'm a newbie so please review carefully.
Not sure if I should add error handling for the get_user call here.
drivers/tty/n_tty.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 94b6eda..5ff63cc 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -1630,6 +1630,7 @@ static int copy_from_read_buf(struct tty_struct *tty,
int retval;
size_t n;
unsigned long flags;
+ unsigned char ch;
retval = 0;
spin_lock_irqsave(&tty->read_lock, flags);
@@ -1645,7 +1646,8 @@ static int copy_from_read_buf(struct tty_struct *tty,
tty->read_cnt -= n;
/* Turn single EOF into zero-length read */
if (L_EXTPROC(tty) && tty->icanon && n == 1) {
- if (!tty->read_cnt && (*b)[n-1] == EOF_CHAR(tty))
+ get_user(ch, b[n-1]);
+ if (!tty->read_cnt && ch == EOF_CHAR(tty))
n--;
}
spin_unlock_irqrestore(&tty->read_lock, flags);
--
1.7.9.5
next reply other threads:[~2012-04-20 15:53 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-20 15:52 Emil Goode [this message]
2012-04-20 21:00 ` [PATCH] drivers/tty: Use get_user instead of dereferencing user pointer Alan Cox
2012-04-21 9:04 ` Jiri Slaby
2012-04-21 14:04 ` Howard Chu
2012-04-21 14:25 ` Howard Chu
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