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Revision 58fca355ad37dcb5f785d9095db5f748b79c5dc2 authored by Srinivasan Shanmugam on 07 February 2024, 04:50:57 UTC, committed by Alex Deucher on 07 February 2024, 23:30:04 UTC 
drm/amd/display: Implement bounds check for stream encoder creation in DCN301
 
'stream_enc_regs' array is an array of dcn10_stream_enc_registers
structures. The array is initialized with four elements, corresponding
to the four calls to stream_enc_regs() in the array initializer. This
means that valid indices for this array are 0, 1, 2, and 3.

The error message 'stream_enc_regs' 4 <= 5 below, is indicating that
there is an attempt to access this array with an index of 5, which is
out of bounds. This could lead to undefined behavior

Here, eng_id is used as an index to access the stream_enc_regs array. If
eng_id is 5, this would result in an out-of-bounds access on the
stream_enc_regs array.

Thus fixing Buffer overflow error in dcn301_stream_encoder_create
reported by Smatch:
drivers/gpu/drm/amd/amdgpu/../display/dc/resource/dcn301/dcn301_resource.c:1011 dcn301_stream_encoder_create() error: buffer overflow 'stream_enc_regs' 4 <= 5

Fixes: 3a83e4e64bb1 ("drm/amd/display: Add dcn3.01 support to DC (v2)")
Cc: Roman Li <Roman.Li@amd.com>
Cc: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Roman Li <roman.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
1 parent e63e35f
Raw File
ioremap.c 
// SPDX-License-Identifier: GPL-2.0
/*
 * Re-map IO memory to kernel address space so that we can access it.
 * This is needed for high PCI addresses that aren't mapped in the
 * 640k-1MB IO memory area on PC's
 *
 * (C) Copyright 1995 1996 Linus Torvalds
 */
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/io.h>
#include <linux/export.h>
#include <linux/ioremap.h>

void __iomem *generic_ioremap_prot(phys_addr_t phys_addr, size_t size,
				   pgprot_t prot)
{
	unsigned long offset, vaddr;
	phys_addr_t last_addr;
	struct vm_struct *area;

	/* An early platform driver might end up here */
	if (WARN_ON_ONCE(!slab_is_available()))
		return NULL;

	/* Disallow wrap-around or zero size */
	last_addr = phys_addr + size - 1;
	if (!size || last_addr < phys_addr)
		return NULL;

	/* Page-align mappings */
	offset = phys_addr & (~PAGE_MASK);
	phys_addr -= offset;
	size = PAGE_ALIGN(size + offset);

	area = __get_vm_area_caller(size, VM_IOREMAP, IOREMAP_START,
				    IOREMAP_END, __builtin_return_address(0));
	if (!area)
		return NULL;
	vaddr = (unsigned long)area->addr;
	area->phys_addr = phys_addr;

	if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot)) {
		free_vm_area(area);
		return NULL;
	}

	return (void __iomem *)(vaddr + offset);
}

#ifndef ioremap_prot
void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
			   unsigned long prot)
{
	return generic_ioremap_prot(phys_addr, size, __pgprot(prot));
}
EXPORT_SYMBOL(ioremap_prot);
#endif

void generic_iounmap(volatile void __iomem *addr)
{
	void *vaddr = (void *)((unsigned long)addr & PAGE_MASK);

	if (is_ioremap_addr(vaddr))
		vunmap(vaddr);
}

#ifndef iounmap
void iounmap(volatile void __iomem *addr)
{
	generic_iounmap(addr);
}
EXPORT_SYMBOL(iounmap);
#endif
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