From 40627e6e291c9dd188e6a2f6d61f983a2ee26576 Mon Sep 17 00:00:00 2001 From: Armin Wolf Date: Sat, 14 Jan 2023 09:50:50 +0100 Subject: [PATCH] ACPI: battery: Fix missing NUL-termination with large strings [ Upstream commit f2ac14b5f197e4a2dec51e5ceaa56682ff1592bc ] When encountering a string bigger than the destination buffer (32 bytes), the string is not properly NUL-terminated, causing buffer overreads later. This for example happens on the Inspiron 3505, where the battery model name is larger than 32 bytes, which leads to sysfs showing the model name together with the serial number string (which is NUL-terminated and thus prevents worse). Fix this by using strscpy() which ensures that the result is always NUL-terminated. Fixes: 106449e870b3 ("ACPI: Battery: Allow extract string from integer") Signed-off-by: Armin Wolf Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin --- drivers/acpi/battery.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c index 974c2df13da1..a49a09e3de1b 100644 --- a/drivers/acpi/battery.c +++ b/drivers/acpi/battery.c @@ -465,7 +465,7 @@ static int extract_package(struct acpi_battery *battery, u8 *ptr = (u8 *)battery + offsets[i].offset; if (element->type == ACPI_TYPE_STRING || element->type == ACPI_TYPE_BUFFER) - strncpy(ptr, element->string.pointer, 32); + strscpy(ptr, element->string.pointer, 32); else if (element->type == ACPI_TYPE_INTEGER) { strncpy(ptr, (u8 *)&element->integer.value, sizeof(u64));