From: Eric Biggers <ebiggers@google.com>
Date: Sat, 3 Mar 2018 00:59:16 +0000 (-0800)
Subject: e2fsck: fix reading fscrypt_symlink_data.len
X-Git-Tag: v1.44.0-rc2~7^2~1
X-Git-Url: https://git.whamcloud.com/gitweb?a=commitdiff_plain;h=6471c19d8edc66ef85c03f83502fc673e7313f74;p=tools%2Fe2fsprogs.git

e2fsck: fix reading fscrypt_symlink_data.len

The ciphertext length field stored at the beginning of encrypted symlink
targets is 16-bit.  But e2fsck_pass1_check_symlink() is reading it as
32-bit.  This was apparently left over from an earlier on-disk format
that was not merged.  Fix it.

This bug caused a small proportion of encrypted symlinks with 4092-byte
targets to be considered invalid by e2fsck, but otherwise had no effect.

Fixes: 62ad24802c6e ("e2fsck: handle encrypted directories which are indexed using htree")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---

diff --git a/e2fsck/pass1.c b/e2fsck/pass1.c
index 7a82536..421fa28 100644
--- a/e2fsck/pass1.c
+++ b/e2fsck/pass1.c
@@ -239,7 +239,7 @@ int e2fsck_pass1_check_symlink(ext2_filsys fs, ext2_ino_t ino,
 			return 0;
 
 		if (inode->i_flags & EXT4_ENCRYPT_FL) {
-			len = ext2fs_le32_to_cpu(*((__u32 *)buf)) + 4;
+			len = ext2fs_le16_to_cpu(*((__u16 *)buf)) + 2;
 		} else {
 			len = strnlen(buf, fs->blocksize);
 		}