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authorNicolas Pitre <nicolas.pitre@linaro.org>2016-07-24 11:30:17 -0400
committerGreg Ungerer <gerg@linux-m68k.org>2016-07-25 16:51:42 +1000
commitc995ee28d29d6f256c3a8a6c4e66469554374f25 (patch)
treeb8f84976a87dcb65671daac9e0be1b5633174586
parent4adbb6ac4b807e2f3f07887cf2a925fa012a7825 (diff)
downloadlinux-c995ee28d29d6f256c3a8a6c4e66469554374f25.tar.bz2
binfmt_flat: prevent kernel dammage from corrupted executable headers
Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
-rw-r--r--fs/binfmt_flat.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
index c3ccdefdeac2..03301bad1f9b 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
*/