The DTB header fields store unsigned values for size and offset, however
we have a 2 GB limit on the overall size, since we use signed "node"
offsets everywhere.
As fdt_open_into() is no exception here, check that the advertised DT
structure size fits in an int, before using that value as an offset into
a buffer.
Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
libfdt/fdt_rw.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/libfdt/fdt_rw.c b/libfdt/fdt_rw.c
index a0f03d0..062edcc 100644
--- a/libfdt/fdt_rw.c
+++ b/libfdt/fdt_rw.c
@@ -437,6 +437,8 @@ int fdt_open_into(const void *fdt, void *buf, int bufsize)
if (can_assume(LATEST) || fdt_version(fdt) >= 17) {
struct_size = fdt_size_dt_struct(fdt);
+ if (!can_assume(VALID_DTB) && struct_size < 0)
+ return -FDT_ERR_NOSPACE;
} else if (fdt_version(fdt) == 16) {
struct_size = 0;
while (fdt_next_tag(fdt, struct_size, &struct_size) != FDT_END)
--
2.17.5
