From: Kars Mulder <kerneldev@xxxxxxxxxxxxx>
[ Upstream commit b1b6bed3b5036509b449b5965285d5057ba42527 ]
The function quirks_param_set() takes as argument a const char* pointer
to the new value of the usbcore.quirks parameter. It then casts this
pointer to a non-const char* pointer and passes it to the strsep()
function, which overwrites the value.
Fix this by creating a copy of the value using kstrdup() and letting
that copy be written to by strsep().
Fixes: 027bd6cafd9a ("usb: core: Add "quirks" parameter for usbcore")
Signed-off-by: Kars Mulder <kerneldev@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/5ee2-5f048a00-21-618c5c00@230659773
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/usb/core/quirks.c | 16 ++++++++++++----
1 file changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/core/quirks.c b/drivers/usb/core/quirks.c
index e0b77674869ce..c96c50faccf72 100644
--- a/drivers/usb/core/quirks.c
+++ b/drivers/usb/core/quirks.c
@@ -25,17 +25,23 @@ static unsigned int quirk_count;
static char quirks_param[128];
-static int quirks_param_set(const char *val, const struct kernel_param *kp)
+static int quirks_param_set(const char *value, const struct kernel_param *kp)
{
- char *p, *field;
+ char *val, *p, *field;
u16 vid, pid;
u32 flags;
size_t i;
int err;
+ val = kstrdup(value, GFP_KERNEL);
+ if (!val)
+ return -ENOMEM;
+
err = param_set_copystring(val, kp);
- if (err)
+ if (err) {
+ kfree(val);
return err;
+ }
mutex_lock(&quirk_mutex);
@@ -60,10 +66,11 @@ static int quirks_param_set(const char *val, const struct kernel_param *kp)
if (!quirk_list) {
quirk_count = 0;
mutex_unlock(&quirk_mutex);
+ kfree(val);
return -ENOMEM;
}
- for (i = 0, p = (char *)val; p && *p;) {
+ for (i = 0, p = val; p && *p;) {
/* Each entry consists of VID:PID:flags */
field = strsep(&p, ":");
if (!field)
@@ -144,6 +151,7 @@ static int quirks_param_set(const char *val, const struct kernel_param *kp)
unlock:
mutex_unlock(&quirk_mutex);
+ kfree(val);
return 0;
}
--
2.25.1
