[PATCH v4 3/9] platform/x86: hp-bioscfg: return -E2BIG from validate_password_input()

[Muhammad Bilal <meatuni001@gmail.com>]

validate_password_input() returns the positive INVALID_BIOS_AUTH on
rejection. store_password_instance() skips the store on nonzero ret,
but its final "return ret < 0 ? ret : count" treats the positive value
as success, so userspace sees count instead of an error.

Return -E2BIG for an invalid password length.

Tested on HP EliteBook 840 G2 (Fedora 44, Linux 7.2.7): writing 999
bytes to current_password returned 999 before this change.

Fixes: 8646a3b5ee3a ("platform/x86: hp-bioscfg: passwdobj-attributes")
Cc: stable@vger.kernel.org
Signed-off-by: Muhammad Bilal <meatuni001@gmail.com>
---
Changes in v3:
 - Return -E2BIG instead of -ERANGE (Andy)

Changes in v2:
 - New patch

 drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c b/drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c
index a9e178637..3f4c45d9b 100644
--- a/drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c
+++ b/drivers/platform/x86/hp/hp-bioscfg/passwdobj-attributes.c
@@ -70,12 +70,13 @@ static int validate_password_input(int instance_id, const char *buf)
 		length--;
 
 	if (length > MAX_PASSWD_SIZE)
-		return INVALID_BIOS_AUTH;
+		return -E2BIG;
 
 	if (password_data->min_password_length > length ||
 	    password_data->max_password_length < length)
-		return INVALID_BIOS_AUTH;
-	return SUCCESS;
+		return -E2BIG;
+
+	return 0;
 }
 
 ATTRIBUTE_N_PROPERTY_SHOW(is_enabled, password);
-- 
2.43.0