The patch titled
sysctl: string length calculated is wrong if it contains negative numbers
has been added to the -mm tree. Its filename is
sysctl-string-length-calculated-is-wrong-if-it-contains-negative-numbers.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: sysctl: string length calculated is wrong if it contains negative numbers
From: "BP, Praveen" <praveenbp@xxxxxx>
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@xxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
kernel/sysctl.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff -puN kernel/sysctl.c~sysctl-string-length-calculated-is-wrong-if-it-contains-negative-numbers kernel/sysctl.c
--- a/kernel/sysctl.c~sysctl-string-length-calculated-is-wrong-if-it-contains-negative-numbers
+++ a/kernel/sysctl.c
@@ -1886,7 +1886,7 @@ static int __do_proc_dointvec(void *tbl_
p = buf;
if (*p == '-' && left > 1) {
neg = 1;
- left--, p++;
+ p++;
}
if (*p < '0' || *p > '9')
break;
@@ -2137,7 +2137,7 @@ static int __do_proc_doulongvec_minmax(v
p = buf;
if (*p == '-' && left > 1) {
neg = 1;
- left--, p++;
+ p++;
}
if (*p < '0' || *p > '9')
break;
_
Patches currently in -mm which might be from praveenbp@xxxxxx are
sysctl-string-length-calculated-is-wrong-if-it-contains-negative-numbers.patch
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