From bd9b0bac6f601655044fc35978e26231dffee03e Mon Sep 17 00:00:00 2001
From: "BP, Praveen" <praveenbp@ti.com>
Date: Wed, 6 Dec 2006 20:39:09 -0800
Subject: [PATCH] [PATCH] sysctl: string length calculated is wrong if it
contains negative numbers
In the functions do_proc_dointvec() and do_proc_doulongvec_minmax(),
there seems to be a bug in string length calculation if string contains
negative integer.
The console log given below explains the bug. Setting negative values
may not be a right thing to do for "console log level" but then the test
(given below) can be used to demonstrate the bug in the code.
# echo "-1 -1 -1 -123456" > /proc/sys/kernel/printk
# cat /proc/sys/kernel/printk
-1 -1 -1 -1234
#
# echo "-1 -1 -1 123456" > /proc/sys/kernel/printk
# cat /proc/sys/kernel/printk
-1 -1 -1 1234
#
(akpm: the bug is that 123456 gets truncated)
It works as expected if string contains all +ve integers
# echo "1 2 3 4" > /proc/sys/kernel/printk
# cat /proc/sys/kernel/printk
1 2 3 4
#
The patch given below fixes the issue.
Signed-off-by: Praveen BP <praveenbp@ti.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
kernel/sysctl.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 7abe9704e75a..6d7147cf66bb 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1875,7 +1875,7 @@ static int __do_proc_dointvec(void *tbl_data, ctl_table *table,
p = buf;
if (*p == '-' && left > 1) {
neg = 1;
- left--, p++;
+ p++;
}
if (*p < '0' || *p > '9')
break;
@@ -2126,7 +2126,7 @@ static int __do_proc_doulongvec_minmax(void *data, ctl_table *table, int write,
p = buf;
if (*p == '-' && left > 1) {
neg = 1;
- left--, p++;
+ p++;
}
if (*p < '0' || *p > '9')
break;
--
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