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authorAlexey Dobriyan <adobriyan@openvz.org>2007-02-10 01:44:39 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-02-11 10:51:24 -0800
commit3ee75ac3c0f4904633322b7d9b111566fbc4a7d3 (patch)
tree2456021d63e95e92ce6bfae2e1f9d83c1843319d
parent8b6312f4dcc1efe7975731b6c47dd134282bd9ac (diff)
[PATCH] sysctl_{,ms_}jiffies: fix oldlen semantics
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@openvz.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--kernel/sysctl.c44
1 files changed, 28 insertions, 16 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 41bbba1a15d..16ef870fa75 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2553,17 +2553,23 @@ int sysctl_jiffies(ctl_table *table, int __user *name, int nlen,
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;
@@ -2581,17 +2587,23 @@ int sysctl_ms_jiffies(ctl_table *table, int __user *name, int nlen,
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;