[PATCH v5 03/15] binfmt_flat: prevent kernel dammage from corrupted executable headers
From: Nicolas Pitre <hidden>
Date: 2016-07-24 15:30:38
Also in:
linux-fsdevel, lkml
Subsystem:
exec & binfmt api, elf, filesystems (vfs and infrastructure), the rest · Maintainers:
Kees Cook, Alexander Viro, Christian Brauner, Linus Torvalds
Signed-off-by: Nicolas Pitre <redacted> --- fs/binfmt_flat.c | 11 +++++++++++ 1 file changed, 11 insertions(+)
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index c3ccdefdea..03301bad1f 100644
--- a/fs/binfmt_flat.c
+++ b/fs/binfmt_flat.c@@ -466,6 +466,17 @@ 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