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[Qemu-devel] [PULL 1/1] device_tree: Fix integer overflowing in load_dev
From: |
Alistair Francis |
Subject: |
[Qemu-devel] [PULL 1/1] device_tree: Fix integer overflowing in load_device_tree() |
Date: |
Tue, 9 Apr 2019 23:55:17 +0000 |
From: Markus Armbruster <address@hidden>
If the value of get_image_size() exceeds INT_MAX / 2 - 10000, the
computation of @dt_size overflows to a negative number, which then
gets converted to a very large size_t for g_malloc0() and
load_image_size(). In the (fortunately improbable) case g_malloc0()
succeeds and load_image_size() survives, we'd assign the negative
number to *sizep. What that would do to the callers I can't say, but
it's unlikely to be good.
Fix by rejecting images whose size would overflow.
Reported-by: Kurtis Miller <address@hidden>
Signed-off-by: Markus Armbruster <address@hidden>
Reviewed-by: Philippe Mathieu-Daudé <address@hidden>
Signed-off-by: Alistair Francis <address@hidden>
Message-Id: <address@hidden>
---
device_tree.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/device_tree.c b/device_tree.c
index 296278e12a..f8b46b3c73 100644
--- a/device_tree.c
+++ b/device_tree.c
@@ -84,6 +84,10 @@ void *load_device_tree(const char *filename_path, int *sizep)
filename_path);
goto fail;
}
+ if (dt_size > INT_MAX / 2 - 10000) {
+ error_report("Device tree file '%s' is too large", filename_path);
+ goto fail;
+ }
/* Expand to 2x size to give enough room for manipulation. */
dt_size += 10000;
--
2.21.0