From 66012982c8e3344b6fc94defba2909356c607a6d Mon Sep 17 00:00:00 2001
From: Michael Halcrow <mhalcrow@google.com>
Date: Wed, 26 Nov 2014 09:09:16 -0800
Subject: eCryptfs: Remove buggy and unnecessary write in file name decode
 routine

commit 942080643bce061c3dd9d5718d3b745dcb39a8bc upstream.

Dmitry Chernenkov used KASAN to discover that eCryptfs writes past the
end of the allocated buffer during encrypted filename decoding. This
fix corrects the issue by getting rid of the unnecessary 0 write when
the current bit offset is 2.

Signed-off-by: Michael Halcrow <mhalcrow@google.com>
Reported-by: Dmitry Chernenkov <dmitryc@google.com>
Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/ecryptfs/crypto.c | 1 -
 1 file changed, 1 deletion(-)

(limited to 'fs')

diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index f71ec125290d..1da2446bf6b0 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -2102,7 +2102,6 @@ ecryptfs_decode_from_filename(unsigned char *dst, size_t *dst_size,
 			break;
 		case 2:
 			dst[dst_byte_offset++] |= (src_byte);
-			dst[dst_byte_offset] = 0;
 			current_bit_offset = 0;
 			break;
 		}
-- 
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