From 2114d3ba91f938bd8db9b1a07f47a0c56211a8c4 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Krzysztof=20Wilczy=C5=84ski?= Date: Thu, 3 Jun 2021 00:01:12 +0000 Subject: [PATCH] PCI/sysfs: Fix dsm_label_utf16s_to_utf8s() buffer overrun MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit bdcdaa13ad96f1a530711c29e6d4b8311eff767c ] "utf16s_to_utf8s(..., buf, PAGE_SIZE)" puts up to PAGE_SIZE bytes into "buf" and returns the number of bytes it actually put there. If it wrote PAGE_SIZE bytes, the newline added by dsm_label_utf16s_to_utf8s() would overrun "buf". Reduce the size available for utf16s_to_utf8s() to use so there is always space for the newline. [bhelgaas: reorder patch in series, commit log] Fixes: 6058989bad05 ("PCI: Export ACPI _DSM provided firmware instance number and string name to sysfs") Link: https://lore.kernel.org/r/20210603000112.703037-7-kw@linux.com Reported-by: Joe Perches Signed-off-by: Krzysztof Wilczyński Signed-off-by: Bjorn Helgaas Signed-off-by: Sasha Levin --- drivers/pci/pci-label.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pci/pci-label.c b/drivers/pci/pci-label.c index 781e45cf60d1c..cd84cf52a92e1 100644 --- a/drivers/pci/pci-label.c +++ b/drivers/pci/pci-label.c @@ -162,7 +162,7 @@ static void dsm_label_utf16s_to_utf8s(union acpi_object *obj, char *buf) len = utf16s_to_utf8s((const wchar_t *)obj->buffer.pointer, obj->buffer.length, UTF16_LITTLE_ENDIAN, - buf, PAGE_SIZE); + buf, PAGE_SIZE - 1); buf[len] = '\n'; }