2.6.32-longterm review patch. If anyone has any objections, please let me know.
------------------ From: Jan Kara <[email protected]> commit a1d47b262952a45aae62bd49cfaf33dd76c11a2c upstream. UDF specification allows arbitrarily large symlinks. However we support only symlinks at most one block large. Check the length of the symlink so that we don't access memory beyond end of the symlink block. Reported-by: Carl Henrik Lunde <[email protected]> Signed-off-by: Jan Kara <[email protected]> [bwh: Backported to 2.6.32: adjust context] Signed-off-by: Ben Hutchings <[email protected]> CVE-2014-9728 Signed-off-by: Willy Tarreau <[email protected]> --- fs/udf/symlink.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/fs/udf/symlink.c b/fs/udf/symlink.c index c3265e1..e28a902 100644 --- a/fs/udf/symlink.c +++ b/fs/udf/symlink.c @@ -76,10 +76,16 @@ static int udf_symlink_filler(struct file *file, struct page *page) struct inode *inode = page->mapping->host; struct buffer_head *bh = NULL; char *symlink; - int err = -EIO; + int err; char *p = kmap(page); struct udf_inode_info *iinfo; + /* We don't support symlinks longer than one block */ + if (inode->i_size > inode->i_sb->s_blocksize) { + err = -ENAMETOOLONG; + goto out_unmap; + } + lock_kernel(); iinfo = UDF_I(inode); if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) { @@ -87,8 +93,10 @@ static int udf_symlink_filler(struct file *file, struct page *page) } else { bh = sb_bread(inode->i_sb, udf_block_map(inode, 0)); - if (!bh) - goto out; + if (!bh) { + err = -EIO; + goto out_unlock_inode; + } symlink = bh->b_data; } @@ -102,9 +110,10 @@ static int udf_symlink_filler(struct file *file, struct page *page) unlock_page(page); return 0; -out: +out_unlock_inode: unlock_kernel(); SetPageError(page); +out_unmap: kunmap(page); unlock_page(page); return err; -- 1.7.12.2.21.g234cd45.dirty -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
