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Subject[PATCH v3 03/12] binfmt_flat: prevent kernel dammage from corrupted executable headers
Date
Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
fs/binfmt_flat.c | 11 +++++++++++
1 file changed, 11 insertions(+)

diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index 36f5bb6b2c..9c76d9a222 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c
@@ -470,6 +470,17 @@ static int load_flat_file(struct linux_binprm * bprm,
}

/*
+ * Make sure the header params are sane.
+ * 28 bits (256 MB) is way more than reasonable in this case.
+ * If some top bits are set we have probable binary corruption.
+ */
+ if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) {
+ pr_err("bad header\n");
+ ret = -ENOEXEC;
+ goto err;
+ }
+
+ /*
* fix up the flags for the older format, there were all kinds
* of endian hacks, this only works for the simple cases
*/
--
2.7.4
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