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RISC-V: Fix out-of-bounds accesses in init_resources()

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init_resources() allocates an array of resources, based on the current
total number of memory regions and reserved memory regions.  However,
allocating this array using memblock_alloc() might increase the number
of reserved memory regions.  If that happens, populating the array later
based on the new number of regions will cause out-of-bounds writes
beyond the end of the allocated array.

Fix this by allocating one more entry, which may or may not be used.

Fixes: 797f0375dd ("RISC-V: Do not allocate memblock while iterating reserved memblocks")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Atish Patra <atish.patra@wdc.com>
Cc: stable@vger.kernel.org
Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
This commit is contained in:
Geert Uytterhoeven 2021-03-12 16:46:34 +01:00 committed by Palmer Dabbelt
parent fa59030bf8
commit ce989f1472
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1 changed files with 2 additions and 1 deletions
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arch/riscv/kernel/setup.c
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@ -147,7 +147,8 @@ static void __init init_resources(void)
bss_res.end = __pa_symbol(__bss_stop) - 1;
bss_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
mem_res_sz = (memblock.memory.cnt + memblock.reserved.cnt) * sizeof(*mem_res);
/* + 1 as memblock_alloc() might increase memblock.reserved.cnt */
mem_res_sz = (memblock.memory.cnt + memblock.reserved.cnt + 1) * sizeof(*mem_res);
mem_res = memblock_alloc(mem_res_sz, SMP_CACHE_BYTES);
if (!mem_res)
panic("%s: Failed to allocate %zu bytes\n", __func__, mem_res_sz);