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authorPavel Emelyanov <xemul@openvz.org>2008-04-29 01:02:44 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-04-29 08:06:23 -0700
commitd7321cd62470b70d2717dae5a963e7a8fabff4d5 (patch)
tree1e3468e44239a310b03c3f8dabf754e64b6ad281 /kernel
parent2c4c7155f25192da3511a6c911db4d08102d36c4 (diff)
sysctl: add the ->permissions callback on the ctl_table_root
When reading from/writing to some table, a root, which this table came from, may affect this table's permissions, depending on who is working with the table. The core hunk is at the bottom of this patch. All the rest is just pushing the ctl_table_root argument up to the sysctl_perm() function. This will be mostly (only?) used in the net sysctls. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: David S. Miller <davem@davemloft.net> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@sw.ru> Cc: Denis V. Lunev <den@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/sysctl.c25
1 files changed, 18 insertions, 7 deletions
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 874e813e40c..d7ffdc59816 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1434,7 +1434,8 @@ void register_sysctl_root(struct ctl_table_root *root)
#ifdef CONFIG_SYSCTL_SYSCALL
/* Perform the actual read/write of a sysctl table entry. */
-static int do_sysctl_strategy(struct ctl_table *table,
+static int do_sysctl_strategy(struct ctl_table_root *root,
+ struct ctl_table *table,
int __user *name, int nlen,
void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen)
@@ -1445,7 +1446,7 @@ static int do_sysctl_strategy(struct ctl_table *table,
op |= 004;
if (newval)
op |= 002;
- if (sysctl_perm(table, op))
+ if (sysctl_perm(root, table, op))
return -EPERM;
if (table->strategy) {
@@ -1471,6 +1472,7 @@ static int do_sysctl_strategy(struct ctl_table *table,
static int parse_table(int __user *name, int nlen,
void __user *oldval, size_t __user *oldlenp,
void __user *newval, size_t newlen,
+ struct ctl_table_root *root,
struct ctl_table *table)
{
int n;
@@ -1485,14 +1487,14 @@ repeat:
if (n == table->ctl_name) {
int error;
if (table->child) {
- if (sysctl_perm(table, 001))
+ if (sysctl_perm(root, table, 001))
return -EPERM;
name++;
nlen--;
table = table->child;
goto repeat;
}
- error = do_sysctl_strategy(table, name, nlen,
+ error = do_sysctl_strategy(root, table, name, nlen,
oldval, oldlenp,
newval, newlen);
return error;
@@ -1518,7 +1520,8 @@ int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user *ol
for (head = sysctl_head_next(NULL); head;
head = sysctl_head_next(head)) {
error = parse_table(name, nlen, oldval, oldlenp,
- newval, newlen, head->ctl_table);
+ newval, newlen,
+ head->root, head->ctl_table);
if (error != -ENOTDIR) {
sysctl_head_finish(head);
break;
@@ -1564,13 +1567,21 @@ static int test_perm(int mode, int op)
return -EACCES;
}
-int sysctl_perm(struct ctl_table *table, int op)
+int sysctl_perm(struct ctl_table_root *root, struct ctl_table *table, int op)
{
int error;
+ int mode;
+
error = security_sysctl(table, op);
if (error)
return error;
- return test_perm(table->mode, op);
+
+ if (root->permissions)
+ mode = root->permissions(root, current->nsproxy, table);
+ else
+ mode = table->mode;
+
+ return test_perm(mode, op);
}
static void sysctl_set_parent(struct ctl_table *parent, struct ctl_table *table)