If the 'buf' array received from the user contains an empty string, the 'length' variable will be zero. Accessing the 'buf' array element with index 'length - 1' will result in a buffer overflow.

Add a check for an empty string.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: e8a60aa7404b ("platform/x86: Introduce support for Systems Management Driver over WMI for Dell Systems") Cc: stable@vger.kernel.org Signed-off-by: Vladimir Moskovkin Vladimir.Moskovkin@kaspersky.com --- drivers/platform/x86/dell/dell-wmi-sysman/passobj-attributes.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/platform/x86/dell/dell-wmi-sysman/passobj-attributes.c b/drivers/platform/x86/dell/dell-wmi-sysman/passobj-attributes.c index 230e6ee96636..d8f1bf5e58a0 100644 --- a/drivers/platform/x86/dell/dell-wmi-sysman/passobj-attributes.c +++ b/drivers/platform/x86/dell/dell-wmi-sysman/passobj-attributes.c @@ -45,7 +45,7 @@ static ssize_t current_password_store(struct kobject *kobj, int length;

length = strlen(buf); - if (buf[length-1] == '\n') + if (length && buf[length - 1] == '\n') length--;

/* firmware does verifiation of min/max password length,