[PATCH 4.14 85/91] USB: gadget: u_f: Unbreak offset calculation in VLAs

From: Greg Kroah-Hartman
Date: Tue Sep 01 2020 - 13:01:49 EST


From: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

commit bfd08d06d978d0304eb6f7855b548aa2cd1c5486 upstream.

Inadvertently the commit b1cd1b65afba ("USB: gadget: u_f: add overflow checks
to VLA macros") makes VLA macros to always return 0 due to different scope of
two variables of the same name. Obviously we need to have only one.

Fixes: b1cd1b65afba ("USB: gadget: u_f: add overflow checks to VLA macros")
Reported-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Brooke Basile <brookebasile@xxxxxxxxx>
Cc: stable <stable@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20200826192119.56450-1-andriy.shevchenko@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/usb/gadget/u_f.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

--- a/drivers/usb/gadget/u_f.h
+++ b/drivers/usb/gadget/u_f.h
@@ -28,9 +28,9 @@
size_t offset = 0; \
if (groupname##__next != SIZE_MAX) { \
size_t align_mask = __alignof__(type) - 1; \
- size_t offset = (groupname##__next + align_mask) \
- & ~align_mask; \
size_t size = array_size(n, sizeof(type)); \
+ offset = (groupname##__next + align_mask) & \
+ ~align_mask; \
if (check_add_overflow(offset, size, \
&groupname##__next)) { \
groupname##__next = SIZE_MAX; \
@@ -46,8 +46,8 @@
size_t offset = 0; \
if (groupname##__next != SIZE_MAX) { \
size_t align_mask = __alignof__(type) - 1; \
- size_t offset = (groupname##__next + align_mask) \
- & ~align_mask; \
+ offset = (groupname##__next + align_mask) & \
+ ~align_mask; \
if (check_add_overflow(offset, groupname##_##name##__sz,\
&groupname##__next)) { \
groupname##__next = SIZE_MAX; \