Commit 5ab58d69 authored by Ville Syrjälä's avatar Ville Syrjälä
Browse files

drm/i915/bios: Validate the panel_name table 



In addition to the fp_timing,dvo_timing,panel_pnp_id tables
there also exists a panel_name table. Unlike the others this
is just one offset+table_size even though there are still 16
actual panel_names in the data block.

The panel_name table made its first appearance somewhere
around VBT version 156-163. The exact version is not known.
But we don't need to know that since we can just check whether
the pointers block has enough room for it or not.

Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405173410.11436-7-ville.syrjala@linux.intel.com


Reviewed-by: default avatarJani Nikula <jani.nikula@intel.com>
parent 58b2e382

drivers/gpu/drm/i915/display/intel_bios.c

+17 −1
Original line number Diff line number Diff line
@@ -206,7 +206,7 @@ static const struct { 
static bool validate_lfp_data_ptrs(const void *bdb,

				   const struct bdb_lvds_lfp_data_ptrs *ptrs)

{

	int fp_timing_size, dvo_timing_size, panel_pnp_id_size;

	int fp_timing_size, dvo_timing_size, panel_pnp_id_size, panel_name_size;

	int data_block_size, lfp_data_size;

	int i;
@@ -221,6 +221,7 @@ static bool validate_lfp_data_ptrs(const void *bdb, 
	fp_timing_size = ptrs->ptr[0].fp_timing.table_size;

	dvo_timing_size = ptrs->ptr[0].dvo_timing.table_size;

	panel_pnp_id_size = ptrs->ptr[0].panel_pnp_id.table_size;

	panel_name_size = ptrs->panel_name.table_size;



	/* fp_timing has variable size */

	if (fp_timing_size < 32 ||
@@ -228,6 +229,11 @@ static bool validate_lfp_data_ptrs(const void *bdb, 
	    panel_pnp_id_size != sizeof(struct lvds_pnp_id))

		return false;



	/* panel_name is not present in old VBTs */

	if (panel_name_size != 0 &&

	    panel_name_size != sizeof(struct lvds_lfp_panel_name))

		return false;



	lfp_data_size = ptrs->ptr[1].fp_timing.offset - ptrs->ptr[0].fp_timing.offset;

	if (16 * lfp_data_size > data_block_size)

		return false;
@@ -268,6 +274,9 @@ static bool validate_lfp_data_ptrs(const void *bdb, 
			return false;

	}



	if (ptrs->panel_name.offset + 16 * panel_name_size > data_block_size)

		return false;



	return true;

}
@@ -291,6 +300,13 @@ static bool fixup_lfp_data_ptrs(const void *bdb, void *ptrs_block) 
		ptrs->ptr[i].panel_pnp_id.offset -= offset;

	}



	if (ptrs->panel_name.table_size) {

		if (ptrs->panel_name.offset < offset)

			return false;



		ptrs->panel_name.offset -= offset;

	}



	return validate_lfp_data_ptrs(bdb, ptrs);

}

drivers/gpu/drm/i915/display/intel_vbt_defs.h

+5 −0
Original line number Diff line number Diff line
@@ -737,6 +737,7 @@ struct lvds_lfp_data_ptr { 
struct bdb_lvds_lfp_data_ptrs {

	u8 lvds_entries; /* followed by one or more lvds_data_ptr structs */

	struct lvds_lfp_data_ptr ptr[16];

	struct lvds_lfp_data_ptr_table panel_name; /* 156-163? */

} __packed;



/*
@@ -778,6 +779,10 @@ struct bdb_lvds_lfp_data { 
	struct lvds_lfp_data_entry data[16];

} __packed;



struct lvds_lfp_panel_name {

	u8 name[13];

} __packed;



/*

 * Block 43 - LFP Backlight Control Data Block

 */