This is a note to let you know that I've just added the patch titled
ACPI: battery: Fix missing NUL-termination with large strings
to the 4.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
acpi-battery-fix-missing-nul-termination-with-large-.patch
and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit d9149cf7a64451c3e4deb63497b6c46aa6b2f02b
Author: Armin Wolf <W_Armin@xxxxxx>
Date: Sat Jan 14 09:50:50 2023 +0100
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 <W_Armin@xxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 42fba8493854f..96aeb0c8cc0e9 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -415,7 +415,7 @@ 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));
