From 9e6766cc8c125cf406960a5bfdf1455473f4835c Mon Sep 17 00:00:00 2001
From: Duane Griffin <duaneg@dghda.com>
Date: Thu, 8 Jan 2009 22:43:48 +0000
Subject: [PATCH] ufs: validate maximum fast symlink size from superblock
The maximum fast symlink size is set in the superblock of certain types
of UFS filesystem. Before using it we need to check that it isn't longer
than the available space we have in the inode.
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/ufs/super.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/fs/ufs/super.c b/fs/ufs/super.c
index 261a1c2f22dd0..e1c1fc5ee2395 100644
--- a/fs/ufs/super.c
+++ b/fs/ufs/super.c
@@ -636,6 +636,7 @@ static int ufs_fill_super(struct super_block *sb, void *data, int silent)
unsigned block_size, super_block_size;
unsigned flags;
unsigned super_block_offset;
+ unsigned maxsymlen;
int ret = -EINVAL;
uspi = NULL;
@@ -1069,6 +1070,16 @@ magic_found:
uspi->s_maxsymlinklen =
fs32_to_cpu(sb, usb3->fs_un2.fs_44.fs_maxsymlinklen);
+ if (uspi->fs_magic == UFS2_MAGIC)
+ maxsymlen = 2 * 4 * (UFS_NDADDR + UFS_NINDIR);
+ else
+ maxsymlen = 4 * (UFS_NDADDR + UFS_NINDIR);
+ if (uspi->s_maxsymlinklen > maxsymlen) {
+ ufs_warning(sb, __func__, "ufs_read_super: excessive maximum "
+ "fast symlink size (%u)\n", uspi->s_maxsymlinklen);
+ uspi->s_maxsymlinklen = maxsymlen;
+ }
+
inode = ufs_iget(sb, UFS_ROOTINO);
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
--
2.30.2