In fb_find_mode_cvt(), iff mode->refresh somehow happens to be 0x80000000,
cvt.f_refresh will become 0 when multiplying it by 2 due to overflow. It's
then passed to fb_cvt_hperiod(), where it's used as a divider -- division
by 0 will result in kernel oops. Add a sanity check for cvt.f_refresh to
avoid such overflow...
Found by Linux Verification Center (linuxtesting.org) with the Svace static
analysis tool.
Fixes: 96fe6a2109 ("[PATCH] fbdev: Add VESA Coordinated Video Timings (CVT) support")
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Helge Deller <deller@gmx.de>
This code has two bugs:
1) "cnt" is 255 but the size of the buffer is 256 so the last byte is
not used.
2) If we try to print more than 255 characters then "cnt" will be
negative and that will trigger a WARN() in snprintf(). The fix for
this is to use scnprintf() instead of snprintf().
We can re-write this code to be cleaner:
1) Rename "offset" to "off" because that's shorter.
2) Get rid of the "cnt" variable and just use "size - off" directly.
3) Get rid of the "read" variable and just increment "off" directly.
Fixes: 96fe6a2109 ("fbdev: Add VESA Coordinated Video Timings (CVT) support")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Helge Deller <deller@gmx.de>
CVT v1.1 spec says: "the vertical front porch shall in all cases be
fixed to 3 lines". The code in fbcvt.c instead sets the _back_ porch to
3 (plus margin).
After swapping cvt.v_front_porch and cvt.v_back_porch the resulting
timings were in line with CVT timings in VESA DMT spec.
The bug seems to be more than 9 years old, but I presume it has not been
noticed as usually the video timings come from the EDID or from the
timing tables in fbdev, and probably swapped values for vfp and vbp work
fine for most of the displays.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: David Ung <davidu@nvidia.com>
Cc: Antonino A. Daplas <adaplas@gmail.com>
Instead of having fbdev framework core files at the root fbdev
directory, mixed with random fbdev device drivers, move the fbdev core
files to a separate core directory. This makes it much clearer which of
the files are actually part of the fbdev framework, and which are part
of device drivers.
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Rob Clark <robdclark@gmail.com>
Acked-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2014-04-17 08:10:19 +03:00
Renamed from drivers/video/fbdev/fbcvt.c (Browse further)
