From e3f5a5f27153228569f3396049838e9727dae86e Mon Sep 17 00:00:00 2001
From: Kay Sievers <kay@vrfy.org>
Date: Fri, 6 Jul 2012 09:50:09 -0700
Subject: [PATCH] kmsg: escape the backslash character while exporting data
Non-printable characters in the log data are hex-escaped to ensure safe
post processing. We need to escape a backslash we find in the data, to be
able to distinguish it from a backslash we add for the escaping.
Also escape the non-printable character 127.
Thanks to Miloslav Trmac for the heads up.
Reported-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Kay Sievers <kay@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/printk.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/printk.c b/kernel/printk.c
index 12886cd19cd9..505863aa3a7f 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -465,7 +465,7 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
for (i = 0; i < msg->text_len; i++) {
unsigned char c = log_text(msg)[i];
- if (c < ' ' || c >= 128)
+ if (c < ' ' || c >= 127 || c == '\\')
len += sprintf(user->buf + len, "\\x%02x", c);
else
user->buf[len++] = c;
@@ -489,7 +489,7 @@ static ssize_t devkmsg_read(struct file *file, char __user *buf,
continue;
}
- if (c < ' ' || c >= 128) {
+ if (c < ' ' || c >= 127 || c == '\\') {
len += sprintf(user->buf + len, "\\x%02x", c);
continue;
}