[PATCH AUTOSEL 4.14 09/11] fbdev: core: syscopyarea: fix sloppy typing

From: Sasha Levin
Date: Sun Oct 29 2023 - 19:04:45 EST


From: Sergey Shtylyov <s.shtylyov@xxxxxx>

[ Upstream commit e8e4a470b677511f9d1ad4f3cef32adc1d9a60ca ]

In sys_copyarea(), the local variable bits_per_line is needlessly typed as
*unsigned long* -- which is a 32-bit type on the 32-bit arches and a 64-bit
type on the 64-bit arches; that variable's value is derived from the __u32
typed fb_fix_screeninfo::line_length field (multiplied by 8u) and a 32-bit
*unsigned int* type should still be enough to store the # of bits per line.

Found by Linux Verification Center (linuxtesting.org) with the Svace static
analysis tool.

Signed-off-by: Sergey Shtylyov <s.shtylyov@xxxxxx>
Signed-off-by: Helge Deller <deller@xxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/video/fbdev/core/syscopyarea.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/core/syscopyarea.c b/drivers/video/fbdev/core/syscopyarea.c
index c1eda31909682..7b8bd3a2bedc5 100644
--- a/drivers/video/fbdev/core/syscopyarea.c
+++ b/drivers/video/fbdev/core/syscopyarea.c
@@ -316,7 +316,7 @@ void sys_copyarea(struct fb_info *p, const struct fb_copyarea *area)
{
u32 dx = area->dx, dy = area->dy, sx = area->sx, sy = area->sy;
u32 height = area->height, width = area->width;
- unsigned long const bits_per_line = p->fix.line_length*8u;
+ unsigned int const bits_per_line = p->fix.line_length * 8u;
unsigned long *base = NULL;
int bits = BITS_PER_LONG, bytes = bits >> 3;
unsigned dst_idx = 0, src_idx = 0, rev_copy = 0;
--
2.42.0