diff options
| author | Roman Smirnov <r.smirnov@omp.ru> | 2024-03-19 11:13:44 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-04-13 12:51:39 +0200 |
| commit | 72d091b7515e0532ee015e144c906f3bcfdd6270 (patch) | |
| tree | dd9ca6bcf367572581ebeefab809b106c8a0b645 | |
| parent | 77f34b9af3abcc21ab2a0483fbe79d1294e6ed64 (diff) | |
| download | linux-72d091b7515e0532ee015e144c906f3bcfdd6270.tar.gz linux-72d091b7515e0532ee015e144c906f3bcfdd6270.tar.bz2 linux-72d091b7515e0532ee015e144c906f3bcfdd6270.zip | |
fbmon: prevent division by zero in fb_videomode_from_videomode()
[ Upstream commit c2d953276b8b27459baed1277a4fdd5dd9bd4126 ]
The expression htotal * vtotal can have a zero value on
overflow. It is necessary to prevent division by zero like in
fb_var_to_videomode().
Found by Linux Verification Center (linuxtesting.org) with Svace.
Signed-off-by: Roman Smirnov <r.smirnov@omp.ru>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/video/fbdev/core/fbmon.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/video/fbdev/core/fbmon.c b/drivers/video/fbdev/core/fbmon.c index 8e2e19f3bf44..dab5fdeafa97 100644 --- a/drivers/video/fbdev/core/fbmon.c +++ b/drivers/video/fbdev/core/fbmon.c @@ -1311,7 +1311,7 @@ int fb_get_mode(int flags, u32 val, struct fb_var_screeninfo *var, struct fb_inf int fb_videomode_from_videomode(const struct videomode *vm, struct fb_videomode *fbmode) { - unsigned int htotal, vtotal; + unsigned int htotal, vtotal, total; fbmode->xres = vm->hactive; fbmode->left_margin = vm->hback_porch; @@ -1344,8 +1344,9 @@ int fb_videomode_from_videomode(const struct videomode *vm, vtotal = vm->vactive + vm->vfront_porch + vm->vback_porch + vm->vsync_len; /* prevent division by zero */ - if (htotal && vtotal) { - fbmode->refresh = vm->pixelclock / (htotal * vtotal); + total = htotal * vtotal; + if (total) { + fbmode->refresh = vm->pixelclock / total; /* a mode must have htotal and vtotal != 0 or it is invalid */ } else { fbmode->refresh = 0; |