From: Alexey Makhalov <amakha...@vmware.com>
Current implementation of grub_relocator_alloc_chunk_align()
does not allow allocation of the top byte.
Assuming input args are:
max_addr = 0xfffff000;
size = 0x1000;
And this is valid. But following overflow protection will
unnecessarily move max_addr one byte down (to 0xffffefff):
if (max_addr > ~size)
max_addr = ~size;
~size + 1 will fix the situation. In addition, check size
for non zero to do not zero max_addr.
Signed-off-by: Alexey Makhalov <amakha...@vmware.com>
Reviewed-by: Daniel Kiper <daniel.ki...@oracle.com>
---
grub-core/lib/relocator.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/grub-core/lib/relocator.c b/grub-core/lib/relocator.c
index 5847aac36..f2c1944c2 100644
--- a/grub-core/lib/relocator.c
+++ b/grub-core/lib/relocator.c
@@ -1386,8 +1386,8 @@ grub_relocator_alloc_chunk_align (struct grub_relocator
*rel,
};
grub_addr_t min_addr2 = 0, max_addr2;
- if (max_addr > ~size)
- max_addr = ~size;
+ if (size && (max_addr > ~size))
+ max_addr = ~size + 1;
#ifdef GRUB_MACHINE_PCBIOS
if (min_addr < 0x1000)
--
2.11.0
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