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authorRusty Russell <rusty@rustcorp.com.au>2010-08-11 23:04:10 -0600
committerRusty Russell <rusty@rustcorp.com.au>2010-08-11 23:04:11 +0930
commit2e9fb9953df91ef6310da22182ca8f4496907502 (patch)
tree096a7b4c2cff57e6fb520f1abdc740260c57471f
parentd2800800d795350435936b08afb402ed9aab1e66 (diff)
downloadlinux-2e9fb9953df91ef6310da22182ca8f4496907502.tar.bz2
params: don't hand NULL values to param.set callbacks.
An audit by Dongdong Deng revealed that most driver-author-written param calls don't handle val == NULL (which happens when parameters are specified with no =, eg "foo" instead of "foo=1"). The only real case to use this is boolean, so handle it specially for that case and remove a source of bugs for everyone else. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Dongdong Deng <dongdong.deng@windriver.com> Cc: Américo Wang <xiyou.wangcong@gmail.com>
-rw-r--r--kernel/params.c20
1 files changed, 3 insertions, 17 deletions
diff --git a/kernel/params.c b/kernel/params.c
index 0b30ecd53a52..3c4a9f1b095e 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -58,6 +58,9 @@ static int parse_one(char *param,
/* Find parameter */
for (i = 0; i < num_params; i++) {
if (parameq(param, params[i].name)) {
+ /* Noone handled NULL, so do it here. */
+ if (!val && params[i].set != param_set_bool)
+ return -EINVAL;
DEBUGP("They are equal! Calling %p\n",
params[i].set);
return params[i].set(val, &params[i]);
@@ -181,7 +184,6 @@ int parse_args(const char *name,
tmptype l; \
int ret; \
\
- if (!val) return -EINVAL; \
ret = strtolfn(val, 0, &l); \
if (ret == -EINVAL || ((type)l != l)) \
return -EINVAL; \
@@ -203,12 +205,6 @@ STANDARD_PARAM_DEF(ulong, unsigned long, "%lu", unsigned long, strict_strtoul);
int param_set_charp(const char *val, struct kernel_param *kp)
{
- if (!val) {
- printk(KERN_ERR "%s: string parameter expected\n",
- kp->name);
- return -EINVAL;
- }
-
if (strlen(val) > 1024) {
printk(KERN_ERR "%s: string parameter too long\n",
kp->name);
@@ -309,12 +305,6 @@ static int param_array(const char *name,
kp.arg = elem;
kp.flags = flags;
- /* No equals sign? */
- if (!val) {
- printk(KERN_ERR "%s: expects arguments\n", name);
- return -EINVAL;
- }
-
*num = 0;
/* We expect a comma-separated list of values. */
do {
@@ -381,10 +371,6 @@ int param_set_copystring(const char *val, struct kernel_param *kp)
{
const struct kparam_string *kps = kp->str;
- if (!val) {
- printk(KERN_ERR "%s: missing param set value\n", kp->name);
- return -EINVAL;
- }
if (strlen(val)+1 > kps->maxlen) {
printk(KERN_ERR "%s: string doesn't fit in %u chars.\n",
kp->name, kps->maxlen-1);