From: Daniel Axtens <d...@axtens.net>
rlocn->offset is read directly from disk and added to the metadatabuf
pointer to create a pointer to a block of metadata. It's a 64-bit
quantity so as long as you don't overflow you can set subsequent
pointers to point anywhere in memory.
Require that rlocn->offset fits within the metadata buffer size.
Signed-off-by: Daniel Axtens <d...@axtens.net>
Reviewed-by: Daniel Kiper <daniel.ki...@oracle.com>
---
grub-core/disk/lvm.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/grub-core/disk/lvm.c b/grub-core/disk/lvm.c
index 7efbaec79..4e17b8897 100644
--- a/grub-core/disk/lvm.c
+++ b/grub-core/disk/lvm.c
@@ -248,6 +248,14 @@ grub_lvm_detect (grub_disk_t disk,
}
rlocn = mdah->raw_locns;
+ if (grub_le_to_cpu64 (rlocn->offset) >= grub_le_to_cpu64 (mda_size))
+ {
+#ifdef GRUB_UTIL
+ grub_util_info ("metadata offset is beyond end of metadata area");
+#endif
+ goto fail2;
+ }
+
if (grub_le_to_cpu64 (rlocn->offset) + grub_le_to_cpu64 (rlocn->size) >
grub_le_to_cpu64 (mdah->size))
{
--
2.11.0
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