udf: Check path length when reading symlink

Symlink reading code does not check whether the resulting path fits into
the page provided by the generic code. This isn't as easy as just
checking the symlink size because of various encoding conversions we
perform on path. So we have to check whether there is still enough space
in the buffer on the fly.

CC: stable@vger.kernel.org
Reported-by: Carl Henrik Lunde <chlunde@ping.uio.no>
Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/udf/namei.c b/fs/udf/namei.c
index c12e260fd6c4..6ff19b54b51f 100644
--- a/fs/udf/namei.c
+++ b/fs/udf/namei.c
@@ -233,7 +233,8 @@ static struct fileIdentDesc *udf_find_entry(struct inode *dir,
                 if (!lfi)
                         continue;
 
-                flen = udf_get_filename(dir->i_sb, nameptr, fname, lfi);
+                flen = udf_get_filename(dir->i_sb, nameptr, lfi, fname,
+                                        UDF_NAME_LEN);
                 if (flen && udf_match(flen, fname, child->len, child->name))
                         goto out_ok;
         }