From: B Horn <b@horn.uk>
Date: Sun, 12 May 2024 01:03:33 +0000 (+0100)
Subject: fs/ufs: Fix a heap OOB write
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c1a291b01f4f1dcd6a22b61f1c81a45a966d16ba;p=thirdparty%2Fgrub.git

fs/ufs: Fix a heap OOB write

grub_strcpy() was used to copy a symlink name from the filesystem
image to a heap allocated buffer. This led to a OOB write to adjacent
heap allocations. Fix by using grub_strlcpy().

Fixes: CVE-2024-45781

Reported-by: B Horn <b@horn.uk>
Signed-off-by: B Horn <b@horn.uk>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---

diff --git a/grub-core/fs/ufs.c b/grub-core/fs/ufs.c
index a354c92d9..01235101b 100644
--- a/grub-core/fs/ufs.c
+++ b/grub-core/fs/ufs.c
@@ -463,7 +463,7 @@ grub_ufs_lookup_symlink (struct grub_ufs_data *data, int ino)
   /* Check against zero is paylindromic, no need to swap.  */
   if (data->inode.nblocks == 0
       && INODE_SIZE (data) <= sizeof (data->inode.symlink))
-    grub_strcpy (symlink, (char *) data->inode.symlink);
+    grub_strlcpy (symlink, (char *) data->inode.symlink, sz);
   else
     {
       if (grub_ufs_read_file (data, 0, 0, 0, sz, symlink) < 0)