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| author | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2020-01-24 23:02:24 +0300 |
|---|---|---|
| committer | Ville Syrjälä <ville.syrjala@linux.intel.com> | 2020-02-15 00:30:04 +0300 |
| commit | 7304b9810a7367131dc26ced61696e7c98dd6666 (patch) | |
| tree | 41e3259c8a484005a34f49ce67d0b1bf07c7ed00 /drivers/gpu | |
| parent | 7f97d3e80649055350e072fbf00bfaed2706f7ec (diff) | |
| download | linux-7304b9810a7367131dc26ced61696e7c98dd6666.tar.xz | |
drm/edid: Check the number of detailed timing descriptors in the CEA ext block
CEA-861 says :
"d = offset for the byte following the reserved data block.
If no data is provided in the reserved data block, then d=4.
If no DTDs are provided, then d=0."
So let's not look for DTDs when d==0. In fact let's just make that
<4 since those values would just mean that he DTDs overlap the block
header. And let's also check that d isn't so big as to declare
the descriptors to live past the block end, although the code
does already survive that case as we'd just end up with a negative
number of descriptors and the loop would not do anything.
Cc: Allen Chen <allen.chen@ite.com.tw>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200124200231.10517-1-ville.syrjala@linux.intel.com
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/drm_edid.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index 1fcec5f4c3ec..3fb280837fdb 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -2217,10 +2217,13 @@ typedef void detailed_cb(struct detailed_timing *timing, void *closure); static void cea_for_each_detailed_block(u8 *ext, detailed_cb *cb, void *closure) { - int i, n = 0; + int i, n; u8 d = ext[0x02]; u8 *det_base = ext + d; + if (d < 4 || d > 127) + return; + n = (127 - d) / 18; for (i = 0; i < n; i++) cb((struct detailed_timing *)(det_base + 18 * i), closure); |