The patch titled
sysctl_{,ms_}jiffies: fix oldlen semantics
has been added to the -mm tree. Its filename is
sysctl_ms_jiffies-fix-oldlen-semantics.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_{,ms_}jiffies: fix oldlen semantics
From: Alexey Dobriyan <adobriyan@xxxxxxxxxx>
currently it's
1) if *oldlenp == 0,
don't writeback anything
2) if *oldlenp >= table->maxlen,
don't writeback more than table->maxlen bytes and rewrite *oldlenp
don't look at underlying type granularity
3) if 0 < *oldlenp < table->maxlen,
*cough*
string sysctls don't writeback more than *oldlenp bytes.
OK, that's because sizeof(char) == 1
int sysctls writeback anything in (0, table->maxlen] range
Though accept integers divisible by sizeof(int) for writing.
sysctl_jiffies and sysctl_ms_jiffies don't writeback anything but
sizeof(int), which violates 1) and 2).
So, make sysctl_jiffies and sysctl_ms_jiffies accept
a) *oldlenp == 0, not doing writeback
b) *oldlenp >= sizeof(int), writing one integer.
-EINVAL still returned for *oldlenp == 1, 2, 3.
Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxxx>
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
kernel/sysctl.c | 44 ++++++++++++++++++++++++++++----------------
1 files changed, 28 insertions(+), 16 deletions(-)
diff -puN kernel/sysctl.c~sysctl_ms_jiffies-fix-oldlen-semantics kernel/sysctl.c
--- a/kernel/sysctl.c~sysctl_ms_jiffies-fix-oldlen-semantics
+++ a/kernel/sysctl.c
@@ -2554,17 +2554,23 @@ int sysctl_jiffies(ctl_table *table, int
void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen)
{
- if (oldval) {
+ if (oldval && oldlenp) {
size_t olen;
- if (oldlenp) {
- if (get_user(olen, oldlenp))
+
+ if (get_user(olen, oldlenp))
+ return -EFAULT;
+ if (olen) {
+ int val;
+
+ if (olen < sizeof(int))
+ return -EINVAL;
+
+ val = *(int *)(table->data) / HZ;
+ if (put_user(val, (int __user *)oldval))
+ return -EFAULT;
+ if (put_user(sizeof(int), oldlenp))
return -EFAULT;
- if (olen!=sizeof(int))
- return -EINVAL;
}
- if (put_user(*(int *)(table->data)/HZ, (int __user *)oldval) ||
- (oldlenp && put_user(sizeof(int),oldlenp)))
- return -EFAULT;
}
if (newval && newlen) {
int new;
@@ -2582,17 +2588,23 @@ int sysctl_ms_jiffies(ctl_table *table,
void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen)
{
- if (oldval) {
+ if (oldval && oldlenp) {
size_t olen;
- if (oldlenp) {
- if (get_user(olen, oldlenp))
+
+ if (get_user(olen, oldlenp))
+ return -EFAULT;
+ if (olen) {
+ int val;
+
+ if (olen < sizeof(int))
+ return -EINVAL;
+
+ val = jiffies_to_msecs(*(int *)(table->data));
+ if (put_user(val, (int __user *)oldval))
+ return -EFAULT;
+ if (put_user(sizeof(int), oldlenp))
return -EFAULT;
- if (olen!=sizeof(int))
- return -EINVAL;
}
- if (put_user(jiffies_to_msecs(*(int *)(table->data)), (int __user *)oldval) ||
- (oldlenp && put_user(sizeof(int),oldlenp)))
- return -EFAULT;
}
if (newval && newlen) {
int new;
_
Patches currently in -mm which might be from adobriyan@xxxxxxxxxx are
origin.patch
sysctl_ms_jiffies-fix-oldlen-semantics.patch
-
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