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Diffstat (limited to 'fs/udf/symlink.c')
-rw-r--r--fs/udf/symlink.c57
1 files changed, 46 insertions, 11 deletions
diff --git a/fs/udf/symlink.c b/fs/udf/symlink.c
index 6fb7945c1e6e..ac10ca939f26 100644
--- a/fs/udf/symlink.c
+++ b/fs/udf/symlink.c
@@ -30,49 +30,73 @@
#include <linux/buffer_head.h>
#include "udf_i.h"
-static void udf_pc_to_char(struct super_block *sb, unsigned char *from,
- int fromlen, unsigned char *to)
+static int udf_pc_to_char(struct super_block *sb, unsigned char *from,
+ int fromlen, unsigned char *to, int tolen)
{
struct pathComponent *pc;
int elen = 0;
+ int comp_len;
unsigned char *p = to;
+ /* Reserve one byte for terminating \0 */
+ tolen--;
while (elen < fromlen) {
pc = (struct pathComponent *)(from + elen);
+ elen += sizeof(struct pathComponent);
switch (pc->componentType) {
case 1:
/*
* Symlink points to some place which should be agreed
* upon between originator and receiver of the media. Ignore.
*/
- if (pc->lengthComponentIdent > 0)
+ if (pc->lengthComponentIdent > 0) {
+ elen += pc->lengthComponentIdent;
break;
+ }
/* Fall through */
case 2:
+ if (tolen == 0)
+ return -ENAMETOOLONG;
p = to;
*p++ = '/';
+ tolen--;
break;
case 3:
+ if (tolen < 3)
+ return -ENAMETOOLONG;
memcpy(p, "../", 3);
p += 3;
+ tolen -= 3;
break;
case 4:
+ if (tolen < 2)
+ return -ENAMETOOLONG;
memcpy(p, "./", 2);
p += 2;
+ tolen -= 2;
/* that would be . - just ignore */
break;
case 5:
- p += udf_get_filename(sb, pc->componentIdent, p,
- pc->lengthComponentIdent);
+ elen += pc->lengthComponentIdent;
+ if (elen > fromlen)
+ return -EIO;
+ comp_len = udf_get_filename(sb, pc->componentIdent,
+ pc->lengthComponentIdent,
+ p, tolen);
+ p += comp_len;
+ tolen -= comp_len;
+ if (tolen == 0)
+ return -ENAMETOOLONG;
*p++ = '/';
+ tolen--;
break;
}
- elen += sizeof(struct pathComponent) + pc->lengthComponentIdent;
}
if (p > to + 1)
p[-1] = '\0';
else
p[0] = '\0';
+ return 0;
}
static int udf_symlink_filler(struct file *file, struct page *page)
@@ -80,11 +104,17 @@ static int udf_symlink_filler(struct file *file, struct page *page)
struct inode *inode = page->mapping->host;
struct buffer_head *bh = NULL;
unsigned char *symlink;
- int err = -EIO;
+ int err;
unsigned char *p = kmap(page);
struct udf_inode_info *iinfo;
uint32_t pos;
+ /* We don't support symlinks longer than one block */
+ if (inode->i_size > inode->i_sb->s_blocksize) {
+ err = -ENAMETOOLONG;
+ goto out_unmap;
+ }
+
iinfo = UDF_I(inode);
pos = udf_block_map(inode, 0);
@@ -94,14 +124,18 @@ static int udf_symlink_filler(struct file *file, struct page *page)
} else {
bh = sb_bread(inode->i_sb, pos);
- if (!bh)
- goto out;
+ if (!bh) {
+ err = -EIO;
+ goto out_unlock_inode;
+ }
symlink = bh->b_data;
}
- udf_pc_to_char(inode->i_sb, symlink, inode->i_size, p);
+ err = udf_pc_to_char(inode->i_sb, symlink, inode->i_size, p, PAGE_SIZE);
brelse(bh);
+ if (err)
+ goto out_unlock_inode;
up_read(&iinfo->i_data_sem);
SetPageUptodate(page);
@@ -109,9 +143,10 @@ static int udf_symlink_filler(struct file *file, struct page *page)
unlock_page(page);
return 0;
-out:
+out_unlock_inode:
up_read(&iinfo->i_data_sem);
SetPageError(page);
+out_unmap:
kunmap(page);
unlock_page(page);
return err;

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